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Comments matching the search albedo:

    More than 100 comments found. Only the most recent 100 have been displayed.

  • What’s going on with the Greenland ice sheet?

    rip71749 at 11:09 AM on 2 September, 2022

    It's hard to be optimistic.  Record temperatures, record fires (Siberia burns year round and Russia started flaring and burning their natural gas that they don't want to send to Europe because they can't shut down their wells), record floods, shrinking albedo and record amounts of fossil fuels used.  Countries are trying to find new sources of fossil fuels.  I live in southern Calif and the temp yesterday was 112oF and probably warmer today and all next week, really hot!  China is turning more to coal, probably India too.  Clearly the world has to work together to solve these problems, and then you look at the top 4 fossil fuel emitters - China, US, India and Russia.  It's hard to imagine those 4 ever working together.  6' by 2100 sounds conservative to me.

  • 2nd law of thermodynamics contradicts greenhouse theory

    MA Rodger at 21:11 PM on 18 July, 2022

    grindupBaker @1509,
    You ask about a particular statement within this talk by Jennifer Kay 2021 'How do clouds affect global warming?'. @6:30 the video addresses the question "How do clouds affect the mean climate?" pointing to a net global mean effect of -21.1Wm^-2 (thus cooling), this comprising -47.3 Wm^-2 (cooling effect) due to albedo and +26.2 Wm^-2 (warming effect) due to a "longwave effect." Thus the statement:-



    [From 8:04] "Clouds also have a longwave effect on the system. Just like greenhouse gases in the atmosphere, clouds absorb and re-emit long wave radiation and that actually causes the surface and the atmosphere to be warm."


     



    My own objection to this statement would go no further than pick up on the use of the term "re-emit."
    Your objection that "only a tiny portion" of the LW radiation arriving at the surface were 're-emitted' from clouds apparently expresses a similar concern.
    But I'm not sure why you would then go beyond simply suggesting the replacement of "re-emit" with "emit". You appear to want to distance these cloud IR emissions from surface warming with description of them setting off "absorb-and-re-emit cycles before succeeding in achieving surface absorption," a description that deploys the very same objectionable "re-emit" term.


    The point the video makes is that the climate system ("the surface and the atmosphere") is warm to the level it is significantly because of this long wave cloud effect. And I think we agree it is this warmth that sets the level of IR whizzing about in the atmosphere as well as the level being absorbed and emitted by the surface.
    (And as a point of note: I recall that perhaps some 10% of the LWR from clouds will be due to reflection and presumably some will be directly returning surface-emitted IR back to the surface.)

  • 2nd law of thermodynamics contradicts greenhouse theory

    MA Rodger at 22:26 PM on 17 July, 2022

    This interchange is getting rather forensic and probably unproductive. All agree. There is a troposhperic lapse rate. Radiation from the atmosphere goes in all directions so at any point the net radiation flux emitted by the atmosphere will be 50% one way and 50% the other, this with the caviat that the lapse rate reduces temperature with altitude and thus emission reduces with altitude (at least within the troposphere).


    grindupBaker @1507,
    You ask for confirmation that absorbed radiation is transferred to atmosphic thermal energy through mollecular collision. This is entirely correct. The average relaxation time for an excited molecule to re-emit is measured in hundredths of seconds while the atmospheric collisions occur in microseconds. Indeed, one of the points I would have made concerning your statements @1505 was use of the term "re-emit" which you allow unchallenged. It is the temperature of the atmosphere that determines (almost all) the radiation it emits, not the radiation being absorbed by that atmosphere.


    I guess your comment (not a lot to do with laws of thermodynamics) is prompted by the often dreadful descriptions of the greenhouse effect we all encounter. But I'm not sure your efforts assist in such general descriptions.


    When discussing the greenhouse effect, it is usually not linked to albedo (as you do) and is best seen in terms of the effective height (and thus temperature) at which the planet radiates to space. Thus it is not so much 'cloud thickness' which you imply @1505 is the important factor, but it is the 'cloud height'.


    Trying to aportion the strength of the GH-effect to particular atmospheric constituents is far from straightforward as their contributions are interdependent. Thus to say O2 & N2 have no part to play is wrong as without them you get a Martian atmosphere which has an insignificant GH-effect. And specific to Earth, while H20 (gas, liquid and solid) is bigger player than CO2, it requires the CO2 to get into the atmosphere.
    Trying to aportion the sensitivity of the GH-effect to particular atmospheric constituents is also far from straightforward.

  • Skeptical Science New Research for Week #26 2022

    Doug Bostrom at 08:10 AM on 4 July, 2022

    "It is physically impossible that the balance is not there."


    Yes, and here in the context of CO2 added to the atmosphere that balance is to do with radiative equilibrium. Equilibrium will happen— accompanied by many changes, mostly of an awkward nature as can be seen if one bothers to check research findings. One can easily calculate a ratio of good/bad by following NR, here. The ratio isn't good. 


    "That meteor 66 millions years ago ( killed dinosaurs and 3- of every 4 living things on earth) lowered the world 5 degrees overnight and darkened the earth completely sunless for 6 years. 30 degree F drop in 6 years, then swinging higher than previous normal and climbing to 2000-2500ppm once the sun returned. It all came back."


    After enough death and dying (aka "evolutionary pressure"), everything was fine— right, got it. And the human species is collectively behaving like a brainless rock, yes. How is this good news, consolation, or reassurance? Meanwhile, thinking in geologic time isn't our nature and as well isn't really helpful in terms of dealing with changes happening right now.


    The irony kicker: 


    "More co2 increases foliage (detected by Nasa's MOTIS), more transpiration, more moisture in the air, more low clouds with higher albedo."


    If one bothered to follow NR and rather than instantly singing a comforting cantata of vague hopes instead read only titles and abstracts of papers listed here, one wouldn't make such a glib, facilely optimistic remark. One would know that neither of those claims pencil out as salvation.

  • Skeptical Science New Research for Week #26 2022

    peppers at 00:53 AM on 4 July, 2022

    I see this as a sort of misplaced approach to this issue, as all this data does little to folks passing by your stand at the swap meet. You are addressing people who may be saying there is no changing happening, and I dont think that remains logical. But some may be saying that to be obstinant or antagonistic. For myself, I dont think that change is happening is hard to see. The crisis stated by all this refers to the hockey puc being a precident in history, and the world will now be ending shortly by a runaway cycle. The train barreling down on a next generations child was the fearsome icon. But the world has experienced this before. That meteor 66 millions years ago ( killed dinosaurs and 3- of every 4 living things on earth) lowered the world 5 degrees overnight and darkened the earth completely sunless for 6 years. 30 degree F drop in 6 years, then swinging higher than previous normal and climbing to 2000-2500ppm once the sun returned. It all came back. My point is that, no matter it happening or the source, the world ( the universe ) balances. More co2 increases foliage (detected by Nasa's MOTIS), more transpiration, more moisture in the air, more low clouds with higher albedo. You will find even more paths of balance if you turn your capable eye to the cycling of nature, meaning the inescapable balance of all cycles. It is physically impossible that the balance is not there, I assure you. I am happy to elaborate more if there is interest. Thanks and best, David

  • Climate Confusion

    peppers at 21:44 PM on 28 June, 2022

    Love the balance acknowledgements. I dont hear this much yet it covers all of nature. By nature I extend to include the universe. Balance to me is like gravity. It is everywhere and will drop the apple on your head for lunch or speed you to demise when you step off the ledge. Orbits, plantlife, rivers and mineral cycles; even the milky way is in a 350M year orbit around our galaxy group. Balance. Co2 is a close brother of oxygen, and even though we draw up old reserves of that goo, Ox too is captured in the limestone and will require storms and erosion to bring it back up. Ox is in a steady decline for a M years in another cycle. I am watching for Co2 to balance with the 20% increase in foliage (Nasa) since 2000, 5% each last couple years, and the evaporation and cooling and added clouds and albedo this brings. Until once again there is balance, as this author references. There are millions of cycles interacting and the only constant is change and a desire to balance, without regard to one species or intent (see apple and falling above). Earth balanced after the big one (which sequestered the co2 and ox in the calcium and carbon slew), back from 4k ppm co2. If we consider balance, then warmer and erosion and trusting gravity and balance could mean the bigger picture just has us hubristically interjecting ourselves in to something, well, that might be needed later. Involving ourselves in something, not past our understanding, but past our paygrade. Interjections we are too important to get understanding just from an apple or acknowledging we know truly little, and that we can and will fall when we go past the edge.

  • Climate Confusion

    Doug Bostrom at 06:54 AM on 28 June, 2022

    Confusion over "warming in the pipeline" reminds me a bit of the general  confusion over the so-called "hiatus" observed in certain temperature records during whenever-to-whenever (1998-...?) any particular study showed a deceleration or halt of temperature rise.


    There was never and could never be a "hiatus" in overall planetary warming short of a vast and mysterious disappearance of various GHG species, or some other impossibility. What appeared to be a slowdown or stall in warming to the extent this showed up in our metrics was (had to be) simply lack of perception on our part, incomplete instrumentation. There was no implausible change in radiative balance, sudden (and oddly unobserved) global albedo change or any other physical means of actually reducing the amount of energy accumulating on the planet. The energy was simply going where certain means of measurement couldn't see it. 


    But "hiatus" means a specific thing in the minds of most people, an actual pause in action. 


    "Warming in the pipeline" and "hiatus" are both examples of hastily conceived, poor terminology, sharing the feature of being mental pitfalls for information consumers of the normal, average variety. 

  • SkS Analogy 2 - Ferrari Without Gas

    Evan at 08:57 AM on 10 March, 2022

    OPOF, actually the quilt works fine for the Snowball Earth condition. Consider the following dialogue.


    "How many blankets do you need to stay warm at night?"


    Thinking of sleeping inside their house, the respondant says, "Two".


    "Oh, you mean two blankets will keep you warm outside tonight?"


    Now aware that the respondent did not think of background temperature, they quickly revise their answer to "four".


    "Oh, you mean four blankets will keep you warm outside tonight in the snow?"


    Now aware that the respondent did not think of background temperature and the geography, they quickly revise their answer to "six".


    "Oh, you mean six blankets will keep you warm outside tonight in the snow in the middle of Antartica?"


    You get the idea. To stay warm, the number of blankets, or the amount of filling in the quilt needed depends on the background temperature, which is controlled partly by the sun's temperature and partly by Earth's albedo, which controls IR radiation. It is never just a matter of the number of blankets or the stuffing in the quilt. :-)

  • It's albedo

    MA Rodger at 22:27 PM on 5 March, 2022

    Bob Loblaw @131,


    I also have struggled to identify any sign of a significant driver of climate in the arguments presented by blaisct. If we wind back to the initial proposal (in the 'Does Urban Heat Island effect exaggerate global warming trends?' thread @59), I feel the scoping of a direct potential forcing can be scoped quite simply** but refining such an analysis does not appear possible with commenter blaisct who now introduces further speculative feedbacks into the discussion, thus piling unhelpfulness on top of unhelpfulness.
    (**According to Wild et at [2015] fig2a, the average land albedo equates to 48Wm^-2(land) = 14Wm^-2(global). If urbaniseation reduced that to zero over 1M sq km, that would equate to a 0.1Wm^-2(global) forcing, thus a maximum value for a quantity which may not even be positive. Note Guo et al [2022] suggest the effect is negative over urbanisation in China.)

  • It's albedo

    Bob Loblaw at 09:04 AM on 3 March, 2022

    I have been watching this discussion for a while, and I too have a really difficult time understanding what blaisct's real purpose or argument is. With respect to albedo, it seems as if he is implying that albedo causes the change in climate, while ignoring the possibility that other factors are changing the climate and albedo is responding to that - the classical albedo feedback that is a standard part of climate science.


    I have access to some high temporal resolution surface radiation data from a continental location. Let's look at four graphs of daily values:


    January radiation and albedo:


    January radiation


    January albedo


    ...and the same location in July


    July radiation


    July albedo


    Let's talk about the last two first. It's a mostly sunny day. with some morning cloud and mid-day scattered cloud. Global radiation peaks at over 1000 W/m2. There is a strong diurnal pattern to albedo - lowest in mid-day (less than 0.2), and highest around sunrise and sunset (around 0.3).


    Then let's compare these to the first two, from January. A similar day in the sense of morning cloud and afternoon clear skies, but global radiation is much lower - (peaks at about 300 W/m2). Albedo is quite different - it drops from about 0.9 in the morning to


    I also know a bit about the temperatures on each day. In July, it was much cooler in the morning and evening, and hottest in the early afternoon. January was much, much colder.


    Should I assume that the differences in albedo have caused those temperature differences? After all, there is a strong correlation: albedo drops, and temperature rises. Very high albedo? Very cold temperatures!


    ...but all I have done is shown that winter is colder than summer, so you can get snow on the ground instead of agricultural crops. After all, the energy input from solar radiation in January peaks at 30% of what it was on that July day, even if we don't account for the higher January albedo and shorter daylight period.


    And the diurnal cycle in July? It is well-known and well-documented that surface albedo shows variability with solar zenith angle in clear skies. The sun is high in the sky at solar noon (which is about 1pm clock time on these graphs), and low in the sky at sunrise and sunset. It's not the albedo that is driving temperature differences: it is the change in solar input.


    Nothing surprising here. Albedo differences are the result of other factors that affect weather and climate.


    I think the same applies to blaisct's humidity and cloud arguments. There is nothing that I can see in his comments that gives any evidence that albedo or humidity are the driving force behind changing climate - they can (and are more likely to be) the result of a changing climate. A feedback, not a forcing.

  • It's albedo

    blaisct at 12:08 PM on 1 March, 2022

    Rodger @128
    Once again thanks for your input and patience. My objective in these three cases was to show the difference in air quality (temp and RH) of possible man-made land changes. These air changes are related to the cloud ceiling.
    Sorry for the errors. I do not do a good job going from my excel sheet to this format. I should have shown the before water step in case 1, and I did copy the results of case 1 wrong.
    To correctly compare these cases a base case enthalpy change must be picked based on real world data that represents the middle part of the earth with the sun shining. I have made lots of temp vs RH plots and came up with 8 kJ/kg(da) as a good average change in enthalpy. The same data shows that adding 2g/kg dry air was typical of tropical conditions.
    The short cut you suggested is ok as long as it crosses the 18g/kg water line and the 74kJ/kg(da) (66+8) line simultaneously. The two albedo cases are ether side of the 8kJ/kg base case at 6.4 kJ/kg and 9.7kJ/kg. I corrected the cases to include the case 1 with out water added and the enthalpy difference for each case. All cases start at the same 25’C and 80%RH.
    Cloud ceiling (m) = (ground temp. – ground dew point)/2.6 *1000*0.3084
    I hope all the errors are out of these cases and we can discuss the conclusions.
    1. These simple cases show that the beginning (event 1) of the LHAC theory in @121is valid in that land changes that result in lower available moisture will produce higher temperatures and lower RH air even if the albedo is increased.
    2. This higher temperature lower humidity air is correlated to cloud ceiling.
    Base case water added: typical rain forest (other vegetation or water sources would have less water added)
    Base case no water: Just to show what the rain forest would look like without water added. Note same enthalpy change and same dew point of all the other cases.
    Low albedo: intended to simulate a UHI.
    High albedo: intended to simulate the rain forest conversion in Amazonia.
    Summary of these cases:
    Base case water added: 8kJ/kg(da), 27.9’C, 75.5% RH, 23.3 dew point calculating 561 m ceiling
    Base case no water: 8kJ/kg(da), 32.5’C, 52.0% RH, 21.4’C dew point calculating 1318 m ceiling
    Low albedo: 9,7kJ/kg(da), 33.4’C, 47.0% RH, 21.4’C dew point calculating 1543 m ceiling
    High albedo: 6.7kJ/kg(da), 31.5’C, 55.5% RH, 21.4’C dew point calculating 1171 m ceiling
    Cloud ceiling and cloud cover should have a negative correlation? This exercise also suggests that the LHAC theory is more related to cloud prevention than destruction. The real-world origins of the ceiling correlation to temp and dew point suggest the plume of hot low RH air reaches high into the atmosphere supporting the model in Figure 3 @121.
    Comments on how big (% of earth’s surface) this effect is? See event 2 calculation @121. I get 7.8% of the earth surface that could be affected by hot low RH air to some degree. Figure 2 @121 show a decreasing RH over time, suggesting low RH air is being produce.

  • It's albedo

    MA Rodger at 07:51 AM on 28 February, 2022

    blaisct @127,


    I'm not sure this interchange is going anywhere. You are not noting the obvious errors in these numbers you are throwing around and if they were corrected I don't see any relevance to the climate change occuring, either globally or regionally.


    On the errors thing, do note that your numbers from the Free Online Interactive Psychrometric Chart are wrong. Consider simplifying the process you are trying to represent. This is not some reversable process so all that matters is the start & end points, not the route between.


    Thus if you choose to start at 25°C & RH=80%, you can add the SH from 16g/kg to 18g/kg (that is 11% increase not 22%) giving RH rising to 89.4% & Enthalpy increasing from 66kJ/kg to 71kJ/kg.
    Now if you add further energy through warming with SH fixed at 18kJ/kg, the enthalpy will rise and the RH will drop with that warming.
    So your Case 3 with an endpoint of 72.3kJ/kg gives a temperature increased from +25°C to +26.2°C & RH drops to 83.6%.
    Your Case 1 with an endpoint of 74kJ/kg gives a temperature increase to +28°C & RH dropping to 75.5%.
    And your Case 2 with reduced albedo giving additional warming to +9.7kJ/kg from the same start conditions yields an endpoint of +29.3°C & RH dropping to 69.7%.


    But these are just numbers. I don't see them relating to what we see of the real world climate change.

  • It's albedo

    blaisct at 09:33 AM on 25 February, 2022

    I don't know what went wrong but I tested these; Online psychrometric chart  and Tutorial


    Please except my assumption and online calculator results in the summary of the three conditions, they are only examples.
    Doing some further research on the clouds I found this site Cloud Ceiling Calc that had a correlation used by airplane pilots to predict cloud celling.


    Cloud ceiling (m) = (ground temp. – ground dew point)/2.6 *1000*0.3084
    The base case is virgin land with lots of trees and vegetation, and is simulated by adding water to the online psychrometric chart calculator. The water added (22% of total water) is typical of data for rain forest type land.
    I have added the cloud ceiling calculation to the summary to show that the LHAC cases increase the cloud ceiling no matter what the albedo is. The high albedo case is 20% higher albedo than the base case and much greater than your chart on W/m^2 vs time. The emphasis of the LHAC theory is that cities and cropland do not put as much water into the atmosphere as the orginal virgin land and this lack of water can reduce the cloud cover.



    Summary of these cases:
    Base case: 29.2’C and 70% RH with 23.3 dew point calculating 701 m ceiling
    Low albedo: 33.4’C and 47% RH with 21.4 dew point calculating 1543 m ceiling
    High albedo: 31.5’C and 55.5% RH with 21.4 dew point calculating 1171 m ceiling
    Cloud ceiling and cloud cover should have a correlation.


     

  • It's albedo

    MA Rodger at 21:08 PM on 24 February, 2022

    blaisct @125,


    Your URLs don't work but...


    I assume when you say @123 that "the psychometric chart in @106 shows the math" you mean that this Free Online Interactive Psychrometric Chart for HVAC engineers does the aritmentic. The "math" is your own. And I would suggest it includes questionable assumptions as well as error and is incomplete. Certainly the contradiction I posed @122 (that Costa et al [2007] showed increasing albedo rather than the required decreasing albedo yet still showed warming temperatures) remains unexplained.

  • It's albedo

    blaisct at 07:35 AM on 24 February, 2022

    Rodger @122
    To show that albedo differences are not that significant, let’s do three examples on the psychometric chart. 1) the land the UHI/cropland was on before. 2) the UHI/cropland with decrease albedo 3) the UHI/land with increased albedo. In event 1 of the LHAC theory we have two things going on: one, the pure albedo effect that is about 0.08W/m^2 for a 0.05 albedo change (not very much), and two the total heat from the sun (about 177 W/m^2) is generating hot low RH air. We will use the psychometric chart to calculate the difference in the “cloud killing” capability of this air in the three cases. You chart at @124 is clearer than mine at @106 but does not show that the yellow lines (wet bulb lines) are constant enthalpy lines (on a dry air basis), constant flux (W/m^2) or the albedo over time transferred to the air (W-hr/m^3 or kJ/kg(dry air)). (if you were an air-conditioner installer this would be related to the HP or tons of your unit, in our case it is the sun’s energy.) We need to get to these units to calculate how much cloud cover this hot low RH air can destroy or prevent, then we can go back to W/m^2.
    I will be honest with you; I use a free online calculator for these charts at Online Interactive Psychrometric Chart


    The site Tutorial is a good tutorial.


    The following is from the interactive site;
    1) For virgin land let’s pick 25’C and 80% relative humidity a little after the sun rises on a clear day, that will put us on the constant specific humidity, SH, line of about 16 g/kg(dry air), the web site call this “Humid.Ratio”. To simulate an sensible heat rise over the course of the day, move right on the constant 16g/kg(dry air) SH line for this example we will stop at 52% RH and 32.5’C (this would be the conditions with no water added) (The 52% RH will match the 8.0 kJ/kg(da)(differences between starting conditions and end of day enthalpy conditions needed to match most cities temp vs RH line, I am sorry this is a trial and error procedure). We will also assume that vegetation and other water sources add water to 18 g/kg(dry air)(22% increase in SH, this is equivalent to one example I found- not much data out there on this) results in an adiabatic cooling (follow yellow line back to right) to 29.2’C and 70% RH on the 18g/kg line.
    2) For decrease in albedo, we will assume 20% higher energy than case 1, or 9.7kJ/kg(da) (this was in range of city data I found), and we will start at the same RH of 80% and 25’C. The trial-and-error calculation yields 33.4’C and 47% RH.
    3) For increase in albedo, we will assume 20% lower energy than case 1, or 6.4kJ/kg(da). The trial-and-error calculation yields 55.5% RH and 31.5’C.
    Note: the temp vs RH for most cities I plotted match the no water added lines in the psychrometric chart.
    Summary of these cases: all cases start at 25'C and 80% RH.
    Base case: 29.2’C and 70% RH water added
    Low albedo: 33.4’C and 47% RH
    High albedo: 31.5’C and 55.5% RH
    The base case is just into the cloud killing/prevention range of 80% and the other two cases are well into the cloud killing/prevention area. This is only an example not a conclusion.
    The next question is how much of the hot low RH air is produced and how much makes it to cloud destruction/prevention. We know from the plume described in Figure 3 of @121 that it is 2-4 X the area of the UHI/cropland. This calculation would require more expertise than I have. I have looked at some very rough numbers (without mixing and pressure change) and get a significant percentage (4%-45%) of the atmosphere that could be affected not counting the probability of getting a chance at cloud destruction/prevention.
    The IPCC has very good mixing and thermo models that should be able to do this.

  • It's albedo

    MA Rodger at 19:08 PM on 22 February, 2022

    blaisct @123,


    It is good we can now see clearly the mechanism (1) to (5) of your LHAC theory in which you propose a driver of increasing global temperatures.


    But then we run into a problem or two.


    If the driver is step (1), a decrease in surface albedo driven by spreading urban development, how can you now say "the change in albedo is not that significant"? The change in albedo is surely the driver of the process. Or is my "translation of LHAC theory" less than correct?
    Perhaps the contradiction I posed @122 (that Costa et al [2007] showed increasing albedo rather than the required decreasing albedo yet still showed warming temperatures) is in some way explained but I do not see it. And identifying the driver of a process is fundamental to such theorising. It appears that has not been achieved.


    You also say the chart @106 shows the maths but I would disagree. The chart sinply plots temperature (aka dry-bulb teperature, aka psycometric temperature) against dew-point temperature to allow heating engineers to calculate water content etc. It does no calculating. (A clearer version of the chart may assist.)


    {sycometric Chart


    And the process concerns changing energy fluxes. While heating engineers may work in W-hr/m^3, in climatology there are a fixed number of hours in a day and of cubic kilometres in the sky. So Wm^-2 is perfectly adequate as a measure of the proposed mechanism at work.

  • It's albedo

    blaisct at 03:36 AM on 22 February, 2022

    Rodger @122
    Yes, your translation of the LHAC theory is correct. Sorry for the whole apple, it was the only way to answer your question. One point of clarification. The production (flux over time) of hot low humidity air (through the day when the sun is shining) will occur no matter what the albedo of the UHI or cultivated land is, so the change in albedo is not that significant but the change in moisture availability is. The albedo affects how hot, water availability affects how low the RH, and area affects how much is produced over time. The Amazonia study showed this. The psychometric chart in @106 shows the math. In the LHAC theory, hot low RH air has always been a part of weather. Over time, man has changed how hot, how low the RH and how much is produced with UHI’s and new cultivated land. The generation of hot low RH air deals with W-hr/m^3 not W/m^2 and destruction of clouds should be on the same W-hr/m^3 basis.
    Correction in @121
    At bottom of @121 should read: we get -1.6W/m^2 change in incoming SW [ 342W/m^2*0.8% cloud cover change*(85% *(1-0.05)+(1-85%)*(1-0.15) – (1- 0.31 earth’s albedo)*(1-50% cloud albedo))]

  • It's albedo

    MA Rodger at 23:33 PM on 20 February, 2022

    blaist @121
    I had the impression the Order of the Day set out @111 was "small bites" but @121 you appear to be serving up a giant five-course meal.


    You seem to be proposing a driver of AGW with a mechanism initiated by (1) a decrease in surface albedo due to the spread of urban areas leading to (2) a rise in surface temperature which in turn leads to (3) reduced relative humidity which leads to (4) reduced cloud cover which then amplifies the warming due to (5) a reduction in cloud albedo. Do correct me if I have misunderstood your proposed mechanism.


    Yet if this suggestion is to hold water, how does it reconcile with the 'Amazonia report' you cite, Costa et al (2007) which (as you describe) "showed that in despite of an increase in albedo from rain forest to crop/pasture, the temperature increased." And this increase in surface albedo with land-use-change is global and has been on-going since 1700 according to your other citation Ghimire et al (2014) whose Fig 2 is pasted below showing a cooling radiative forcing (inset rising albedo).
    Ghimire et al (2014) fig2
    So if there is an increase in surface albedo, what is it causing the increasing global temperature and thus kicking-off your proposed mechanism, (1) to (5) above? Why would we be experiencing warming if globally surface albedo has been increasing since 1700?

  • It's albedo

    blaisct at 07:28 AM on 20 February, 2022

    MA Rodger @112
    Before I answer your question on whether there is something other than AGW causing global warming. Let me clarify that I am not a skeptic on Anthropical Global Warming, AGW, I firmly believe that man’s activities are causing AGW. The paper Dubal & Vahrenholt expressed doubt that the 20 years of CERES data showed significant evidence of GHG caused AGW and that clouds were the significant factor. How is cloud cover related to AGW? The Skeptical web site seems to be committed to evaluating theories. Here is the answer to your question:
    The data I have looked at (below) suggest that AGW is not cause by one thing but a series of interactive events starting with land albedo and ending with ocean/land albedo and relative humidity (not specific humidity) in the middle. You will see (below) that this cycle of events is a known cycle in weather and that man’s activities have interfered with the cycle to cause AGW. For lack of a better name, I will call the cycle of events the “Low Humidity Albedo Cycle”, LHAC. The LHAC cycle back in the 1700-1800 (with low man-made albedo change) was:
    Event 1: Over land on sunny days the temperature rises and the relative humidity, RH, drops through the day no matter what the albedo of the land is. How much the RH drops depends on availability of water from liquid water evaporation or plant transpiration. If no water is added to this daily event the specific humidity, SH, will remain constant while the RH drops. With water available the RH does not drop as much and the SH increase. The energy fueling this event (sunny days) depends on the albedo and latitude of the land, the lower the albedo and the closer to the equator the stronger this event. Clouds greatly dampen this event.
    Event 2: The air above this land is hot and dryer and it rises all day long, creating a plume of rising hot low humidity air. That plume of air moves with the prevailing winds usually to the east in a circling pattern due to the Corellas effect.
    Event 3: This hot low RH air is hungry for water. If this air finds clouds it eats away at them until the air is saturated with water, this process cools the air and raises the SH and RH. If this hot low RH air does not find a cloud it can cool as the pressure drops at the higher altitudes or it can serve as a deterrent to cloud formation. In all cases it reaches saturation.
    Event 4: With fewer clouds more sun can reach the earth and warm the land and oceans, this is the final albedo decrease event. This last albedo event is the strongest because the change in albedo in the greatest with no clouds in the way of direct sun light. The warmer oceans store some of this energy and evaporate more water - find cold air and make more clouds.
    This natural LHAC cycle of event will remain stable if the albedo and moisture availability remain constant. Let’s take each event and look at its contribution to the total AGW since 1880:
    Event 1: Since 1700-1880 man has made some small changes in land use albedo but a large change in the land area. Most of these albedo changes came along with a decrease in moisture availability. UHI’s are most noted, with albedo changes between 0 and 0.2 depending on what the city replaced. I don’t have a source for the average, I will assume 0.05 average albedo change. The urban area has increased to about 3% of the earth’s land mass for all cities. I have no trouble doubling that to 6% for all man-made structures, rural + urban, they all have lower albedos and generate heat. Go to any city at Climate data and you can find the daytime data for temperature vs RH, in the morning the RH is high and as the day progress the temperature rises and the RH drops sometimes to 40% RH or lower, this is a normal psychometric thermodynamic process. Figure 1 is an example of daily RH from Beijing and is typical of most cities (just focus on the day time).



    Figure 1


     


     


    The change in albedo flux of all the earth’s cities is estimated at 0.08W/m^2 (assuming 177W/m^2 sun to the city, 50% cloud cover, 0.05 albedo change, 3% of land mass cities). Even if we make larger assumptions, we still can’t get to the 2.2W/m^2 we are looking for to account for all the AGW since 1880 or the 1.3 W/m^2 in Dubal & Vahrenholt . These cities can have daily temperature rise of up to 8’C. A large part of this temperature rise is due to the psychometric rise, PR, in temperature while the RH drops at a constant energy input (albedo). Looking at temperature anomalies, SH, and RH all plotted together vs time, Figure 2, we see they are all correlated (Temp and SH positively, and Temp and RH negatively).



    Figure 2


    If PR were not occurring on a global basis the RH and SH would both have a positive slope. Using the psychometric chart in @106 we can get the average temperature rise per % RH of -0.15 ‘C/%RH. The slope of the RH data in (2) is 0.16%RH/decade, for the 40 years of the chart this is 0.6% change in RH, giving a PR temp rise of 0.1’C for the 40 years vs the 0.7’C observed, small but not insignificant.  This hot low RH air has no W/m^2 flux as it leaves the UHI; but, the hot low RH air has potential energy gain in getting saturated with water. Let’s add the crop/pasture land albedo changes to the UHI's. Globally the change since 1880 from virgin land to crop/pasture was about 6% with little change in albedo (Global albedo change); but, with low moisture change. The most notable of these changes was the deforestation of the Amazonian rain forest to make crop and pasture land Amazonia report (and @106). Amazonia report showed that in despite of an increase in albedo from rain forest to crop/pasture the temperature increased, the RH deceased, the cloud cover decreased, and the rain decreased. Classic example of psychometric temperature and RH behavior. Most likely all of this global 6% increase in crop/pasture land is producing hot low RH air just like the UHI’s. Combining the UHI and crop/pasture land changes we get 9% of the earth’s land mass producing more hot low RH air than 1880.
    Event 2: This hot low relative humidity air rises and goes downwind from the UHI or changed crop/pasture land. The picture from (6) shows the extent of the UHI plume from Chicago, Il.



    Figure 3


     


    This is a computer model tuned with real data and calculates the extent of the plume to be 2 to 4 time the area of the UHI. The model also predicts the shape of the plume, rising to where some clouds could be. Using 3 times as the average extent of the plume we now get 27% of the land mass (7.8% of the earth) being affected by plumes like the one in Figure 3.
    Event 3: Cloud destruction/prevention is the closest target for the hot low RH plume; but, if clouds are not available the lower pressure will saturate it or it will mix with cooler air. When this plume of hot low RH air increases its RH to 80% it is no longer is a threat to clouds or cloud prevention. Clouds and RH observations are that almost no clouds can form below 60% RH and significant reductions will occur below 80% RH.



    Figure 4


    Data shown in the figure 4 shows a 41%/decade decrease in clouds over 40 years.  Dubal & Vahrenholt Figure 9 show about 0.57%/decade decrease, this data can be correlated to Figure 2 RH data and get 2.7% change in cloudiness/change in RH (R^2 =0.63).  Not the best correlation but shows there is a relationship.  
    Event 4: The reduce cloud cover exposes more land and ocean to the sun. This land and ocean are located in the middle 75% of the earth where the cloud cover is about 50% vs about 60% for the whole earth, also assuming albedo of clouds is 50%. The sun’s flux to this exposed area is the cloud free flux of 342 W/m^2 (1367/4).  Dubal & Vahrenholt suggest this energy is split 85% over ocean (0.05 albedo) and remainder over land (0.15 albedo). Using 40%/decade cloud cover for 2 decades of CERES data we get -1.6W/m^2 change in incoming SW [ 342W/m^2*0.8% cloud cover change*(85% *(1-0.05)+(1-80%)*(1-0.15))]. A little greater than the -1.3 W/m^2 observed; but close enough to show that the LHAC theory is plausible.

  • It's albedo

    nobodysknowledge at 21:28 PM on 12 February, 2022

    Thank you for your presentation of the Dübal and Vahrenholt 2021-paper blaisct. I think there is a good overall agreement to the CERES data presented by Loeb et al 2021. I have commented this at Science of Doom. 


    The Dübal and Vahrenholt paper, Radiative Energy Flux Variation from 2001–2020, have got some attention. And for good reason. It is an important discussion. But there are some problems with some of the claims that are made.


    «Radiative energy flux data, downloaded from CERES, are evaluated with respect to their variations from 2001 to 2020. We found the declining outgoing shortwave radiation to be the most important contributor for a positive TOA (top of the atmosphere) net flux of 0.8 W/m2 in this time frame.»
    According to the CERES data they present (TOA all sky), the trend is LW out 0,28 W/m2/decade (cooling), SW out -0,70 (warming), and solar reduction 0,03 (cooling), wich gives a TOA warming trend of 0,39 W/m2/dec. So far so good. And in good agreement with Loeb et al 2021. EBAF Trends (03/2000-02/2021) 0.37 + 0.15 Wm-2 per decade.


    «The declining TOA SW (out) is the major heating cause (+1.42 W/m2 from 2001 to 2020).»
    Trend SW out all sky -0,70 W/m2/dec withsolar reduction included (0,70 W/m2/dec TOA warming). Gives 1,40 W/m2 over 20 years. This major heating is composed of SW clear sky heating trend of -0,37 W/m2/dec and a SW cloudy sky heating trend of -0,78 W/m2/dec. In the TOA radiation energy bridge-chart (figure 14) this is shown as SW clear sky increase of 0,15 W/m2 and SW cloudy areas increase of 1,27 W/m2. And the solar change impact is -0,17 W/m2 for 20 years. A great difference between trend and energy bridge-chart.
    Loeb et al has a SW TOA heating of 0,63W/m2/dec through albedo change, with clouds increasing absorbed SW Flux 0,44W/m2/dec and surface increased absorption 0,19W/m2/dec. In good agreement with Dübal and Vahrenholt. EBAF Trends (03/2000-02/2021) 0.68 + 0.12 Wm-2 per decade.


    «It is almost compensated by the growing chilling TOA LW (out) (−1.1 W/m2).»
    But as we have seen, the trend is only 0,28 W/m2/dec. This is composed of LW TOA flux clear sky 0,04W/m2/dec and LW cloudy sky 0,35 W/m2/dec. How can they claim so big «chilling» longwave cooling? It looks like they use the startpoint and endpoint of a graph, and that the «chilling» cooling at TOA was for the year 2020 relative to 2001. In the TOA radiation energy bridge-chart (figure 14) this is shown as LW clear sky increase of 0,46 W/m2 and LW cloudy areas increase of 0,64 W/m2. I think what is presented in the bridge-charts is close to cherrypicking.
    Loeb et al EBAF Trends (03/2000-02/2021) -0.31 + 0.12 Wm-2 per decade


    The Dübal and Vahrenholt calculations for cloudy areas are clearly showing how thinning of clouds is the greatest component of global warming for the last 20 years, and probably for 40 years when we read the papers of M Wild and other cloud scientists. So when some say that the AGW is the cause of all global brightening or of all increase in water vapor, they are not taking the attribution problem serious. Increasing surface and atmospheric temperatures is contributing a lot, but there is a great complexity behind all this. 

  • It's albedo

    MA Rodger at 23:36 PM on 10 February, 2022

    blaisct @115,
    And concerning your second question - "If all the global warming, GW, came from CO2 radiative forcing alone would not a graph like @111 be flatter...?"


    The 'graph @111' is Fig 3 of Dübal & Vahrenholt (2021) and specifically shows a quite-dramatic reduction in albedo 2001-20 with a trend of -0.70Wm^-2/decade. Fig 1 shows a reduction in solar of -0.03Wm^-2/d. Thus Figs 1 & 3 matches Loeb et al (2021) Fig 2d with Absorbed Solar 2002-20 given as +0.67Wm^-2/d. Loeb et al Fig 2d also presents an attribution of this increased absorbed solar warming 2002-20, ☻ 60% cloud albedo, ☻ 7% water vapour, ☻ 4% GHGs, ☻ 26% surface albedo, ☻ 3% aerosol. And note also that Loeb et al Fig 2a shows this 'quite-dramatic' effect occurs almost totally 2013-20.


    To explain this attribution; if 4%+7% of this increase-in-Absorbed Solar (decrease-in-albedo) is attributed to GHGs, this means additional GHGs+water-vapour is directly preventing solar being otherwise reflected away and instead directly absorbed by the increased GHG+water-vapour. The underlying cause for the water vapour increase is of course AGW.


     


    Your question implies that you consider there is something other than AGW and increased CO2 driving a significant part of this increase-in-Absorbed Solar (decrease-in-albedo) 2002-20. I don't think I could agree.


    Loeb et al does identify the geography of the various components of the net EEI, mapping them out in Fig 3 and pointing to the Surface effect being "greatest in areas of snow and sea-ice, where significant declines in coverage have been observed in recent decades." It is, of course, easy to see that the ice-loss is due to AGW.


    And for the biggest component, Cloud, Loeb et al says "Regional trends in net radiation attributable to changes in clouds are strongly positive along the east Pacific Ocean, while more modest positive trends occur off of the U.S. east coast and over the Indian, Southern, and central equatorial Pacific Oceans." Is this the finger print of AGW? If it isn't, it would require an alternative causation.


    If AGW is the cause, note that the increase-in-Absorbed Solar (decrease-in-albedo) 2002-20 is mainly occuring 2013-20 which matches the global temperature record showing 70% of the 2002-20 warming occurred in the period 2013-20.


    So without further explanation, I see no reason to expect a "flatter" slope from CO2-forcing alone, the slope being presumably all down to AGW.

  • It's albedo

    MA Rodger at 10:33 AM on 7 February, 2022

    blaisct @111,
    You say you want to "take smaller bites out of albedo apple" which is probably advisable and presumably it is also advisable to start from the first "small bite."



    So we have set out in Dübal & Vahrenholt (2021) for the 19 year period 2001-20 a trend in 'Incoming Solar (TOA)' of -0.0035Wm^-2/yr and a trend of 'Shortwave Out (TOA) ' -0.0704Wm^-2/yr of and thus an inferred trend in 'Absorbed Solar' of +0.0669Wm^-2/yr which would thus equate to +1.27Wm^-2 'Absorbed Solar' over the 19 years. So far so good.
    You then assert that the "change in global temperature over the CERES time period is about +0.45ºC" which is a reasonable value for global SAT 2001-20 although its best if its derivation was properly explained. But, so good so far.
    You then assert that this temperature increase of +0.45ºC is in some way equivalent to +0.9Wm^-2 per 20 yrs. That step does certainly need explaining.
    And if that explanation is convincing (warning - that is very unlikely to happen), when that explanation is provided, it would help why the discrepancy between 0.9 and 1.3 can also allow the two to be considered as "an almost perfect fit."


    And when these "small bites out of albedo apple" have been digested, the relevance of your first question may be more evident.

  • It's albedo

    blaisct at 04:24 AM on 7 February, 2022

    Ref my @104 and @106 replies
    Thanks again for the comments. I can see that I need to take smaller bites out of albedo apple in the CERES data. Let me start with Hans-Rolf Dübal et al 2021 graph of CERES data.




    Hans-Rolf Dübal et al 2021 does not have an official albedo change graph (change in sun’s energy out -change in sun’s energy in). The graph above needs to be correct for the small (-0.07 W/m^2/20 years) in coming energy (correction is: -1.3W/m^2/20 years). My post @104 has that correction in a graph. The change in global temperature over the CERES time period is about 0.45’C or -0.9 W/m^2/20 years. Over laying that on the graph above one can see an almost perfect fit (slightly higher slope for CERES data) (can’t show that in this format).
    First question: Does an almost perfect fit of global temperature to CERES albedo (in W/m^2) mean albedo is the main cause of global warming for the 20 years of CERES data? (Regardless of what caused the albedo change or the short 20 years of data)
    Second question: Should the slope of the albedo graph above be different (flatter) than the actual global temperature if CO2 caused radiative forcing was at work; since, CO2 caused radiative forcing does not use albedo change energy to cause global temperature rise?
    Any answer to these questions would help me understand the CERES data before exploring what caused the albedo change in CERES data.

  • How much has nuclear testing contributed to global warming?

    Bob Loblaw at 11:16 AM on 25 January, 2022

    Clay Hansen:


    I was able to open the link in your first comment. It does not make your argument stronger.


    A few key errors:



    • Equations 2 and 3 are incorrect. You have assumed that energy in = energy out (solar vs earth's emissions to space).


      • It takes time for the earth-atmosphere system to respond to an imbalance between energy in and energy out.

      • The speed at which it responds depends on the heat capacity.

      • For the atmpsphere only - ignoring land or water - the e-folding time is on the order of 200 days.

      • If you include the ocean mixed layer (60 to 70m depth), we are talking a decade or two for it to respond to an energy imbalance.

      • The deeper ocean takes even longer.

      • It is impossible to model temperatures on an annual basis without inclduing these heat capacity issues and non-equilibrium conditions.


    • Equation 4 is incorrect. You have assumed that the energy in can be calculated from the difference between the σT4 terms for solar (6000K) and terrestrial (assuming about 255K or 288K, you don't specify) along with a "shape factor".


      • No such constant "shape factor" can be used for both sources (solar, terrestrial).

      • σT4 for solar temperature gives a flux at the surface of the sun. The earth is not located that close to the sun. You need to account for the difference in area between a sphere with the radius of the sun, and a sphere with a radius of the earth's distance from the sun.

      • The solar radiation received from the sun also needs to be reduced by a factor of 1/4 to account for the area of the earth as a sphere vs the area of the earth as a disk.

      • The solar radiation absorbed by the earth also need to account for global albedo.

      • You may claim that your shape factor accounts for this - but the "shape factor" for solar radiation (which is simple geometry) is vastly different from any "shape factor" for earth's emissions to space, and you only have one "shape factor".

      • Since the solar "shape factor" is purely geometric, it will not vary over time as you assume in equation 5b.



    Given these fundamental errors in the first equations of your model, the rest is nonsense. I did not bother to try to follow the rest of your mathematics, as the initial assumptions are fundamentally wrong.

  • It's albedo

    Bob Loblaw at 02:19 AM on 28 December, 2021

    blaisct @ 106:


    Although it has been almost two weeks since your post, and others have commented, I wish to respond to one statement you have in your opening paragraph. You state:



    My understanding has been expanded to include: AGHs hotter temperature will reduce humidity and thus reduce cloud cover, expose more earth surface to the sun thus reduce earths albedo; therefor, albedo vs time for AGHs may not be flat.



    The "hotter temperatures will reduce humidity" does not follow. If air temperature increases and absolute humidity does not change, then yes, relative humidity will decrease, but we have no a priori reason to expect this to be the case.


    I suggest that you review the use of differnt terms for "humidity", which can get quite confusing at times. Wikipedia has a decent page covering this.


    A warmer atmosphere is expected to increase evaporation, which will add water vapour to the atmosphere. This cannot go on indefinitely, and globally we expect a new equilibriium where increased evaporation is matched by increased precipitation. At this new equilibrium, we expect global absolute humidity to be higher, and global relative humidity to be roughly the same as now.


    Spatial variation will almost certainly be different, and exactly how cloud cover will respond has uncertainties, but it is not as simple as you describe.


    Usually, the incorrect assumption you will see in the comments here goes along the lines of "more evaporation = more cloud". This is also far too simplistic. The balance between temprature, evaporation, cloud formation, and precipitation is a complex and delicate one.

  • It's albedo

    MA Rodger at 09:45 AM on 17 December, 2021

    blaisct @108,
    You talk of a "correlation in figure 2(f) CERES 20 years 2 (aka Loeb et al 2021)" which I find most odd as I see no correlation there. The figure 2(f) simply presents an attribution of the increasing IEE 2005-20, the sum of the attributions presented in figs 2(d) & 2(e). I thus fail to see any "conflict" between Fig 2(f) & fig 1. The total of the attributed components presented in fig 2(f) (+0.41Wm^-2/decade) is also the trend for the data shown in fig 2(c), CERES data which differs from fig1 only in that it covers a slightly extended period. I am thus not seeing any "conflict".
    And do be aware that the "in situ" (data which is in the main Ocean Heat Content data) is presented as a check on the CERES net values. If there was not a good fit between the OHC & CERES data, the CERES data would be seen as le robust with its use within the analysis thrown into some doubt. So the view that CERES should show less trend than "situ data if GHGs were a significant effect" doesn't stack up at all.


    Loeb et al (2021) is saying that CERES shows an increasing trend in downward radiation of +0.65Wm^-2/decade, part balanced by an increasing trend of +0.24Wm^-2 upward radiation, yielding a net downward EEI trend of +0.41Wm^-2. And a 'Partial Radiative Perturbation Analysis' attributes this net EEI trend almost entlrely to factors directly or indirectly resulting from AGW, these factors being:-
    +0.25Wm^-2/decade due to cloud albedo (which will comprise a reduction in cloud fraction and an indirect aerosol effect which presumably will be negative through this period).
    +0.31Wm^-2/deacde due to increasing water vapour (this due to global warming).
    +0.22Wm^-2/decade due to "other" effects (dominated by increased GH gases as well as a small solar variation which would have been negative through the period).
    +0.18Wm^-2/decade due to secreasing surface albedo (this shown in polar and mountain ragions and thus again a product of global warming reducing ice/snow cover.
    +0.01Wm^-2/decade due to a reduced direct aerosol effect.
    -0.53Wm^-2/decade due to a warmer planet increasing outward radiation.


    I do not see any correlation between albedo and global temperature, certainly not in Loeb et al (2021). Perhaps you could explain where you see it.


    These EEI trends acting since 2005 have collectively added some 0.7Wm^-2 to the EEI over the period to a start-of-period EEI of 0.4Wm^-2. Finally there is a concern that these 2005-20 trends are perhaps not representitive of the long-term trend. One factor not addressed by the analysis is the potential for significant short-term effects due to the situation prior to the period (thus the start-of-period EEI of 0.4Wm^-2 may be a poor start point). Loeb et al do consider short-term effects acting during the period 2005-20 that may abate long-term, specifically the PDO.

  • It's albedo

    blaisct at 01:39 AM on 17 December, 2021

    MA Rodger @107
    Thanks for your comments. The correlation in figure 2(f) CERES 20 years 2 (aka Loeb et al 2021) to GHG was noted but it is in conflict with the extremely good fit of CERES data to in situ in figure 1 CERES 20 years 2 which should show a smaller slope (of the statical fit) than the in situ data if GHGs were a significant effect. The conflict could be explained by the GHG if their effect on cloud formation is so strong that the GHG effect can not be seen in Figure 1 only the cloud effect can be seen; or that the GHG data in Figure 2(f) is confounded with another variable. With just 20 years of data, we can’t tell yet.
    My biggest takeaway from the reports in @106 was finally seeing a correlation to albedo that fit the observed temperature rise over 20 years. You are right in that this is only 20 year and not the 150 years of concern.
    The unproven theories at the bottom of @106 are just possible theories of unknown significance that may explain the Figure 1 correlation. I put them there incase someone had someone data on the subject.

  • It's albedo

    blaisct at 05:08 AM on 15 December, 2021

    Once again thanks for your comment (MA Rodger and the editor) and the additional papers on the subject. I will try to do better with the links.



    The earlier data I was referring to was earthshine 10 years and CERES 10 years which showed that the data for the earths albedo was very noisy and flat. The flat part was what was expected for anthropogenic greenhouse gas , AGH, global warming. My initial understanding of AGH radiative forcing was that AGHs absorbed radiation (got hot) and that the higher the AGH concentration (at constant radiation) the more heat it could hold back thus the temperature would increase but the energy in vs out of the zone where this occurred would be the same (albedo would be flat). My understanding has been expanded to include: AGHs hotter temperature will reduce humidity and thus reduce cloud cover, expose more earth surface to the sun thus reduce earths albedo; therefor, albedo vs time for AGHs may not be flat.
    The new (new to me) data I sited Earthshine 20 years showed a decrease albedo from both earthshine and CERES data – my only interest is this report was the agreement with earthshine an CERES data. The editor’s link CERES 20 years 1  and another link CERES 20 years 2 provided a lot more CERES data with different analyses. These three papers are the first time I have seen data showing a decrease in albedo (increase in TOA radiation) vs time. If all climate change was due to AGHs this graph would be flat. Using the CERES 20 years 2  graph for TOA radiation out. (of the three links I chose this one because it has the In Situ data (earth surface temperature)) one can see the good correlation between In Situ data and CERES data



    Figure 1
    “Comparison of overlapping one-year estimates at 6-month intervals of net top-of-the-atmosphere annual energy flux from the Clouds and the Earth's Radiant Energy System Energy Balanced and Filled Ed4.1 product (solid red line) and an in situ observational estimate of uptake of energy by Earth climate system (solid blue line). Dashed lines correspond to least squares linear regression fits to the data.”



    . If there was any AGH global warming mixed In with the TOA (red) data it would have a slope lower than the In Situ data. The report CERES 20 years 1  did look for the AGH flat line signal and found it in the “Clear Sky” LW (long wave) data but nowhere else (1 of four graphs).
    Two of these reports put a lot of emphasis on clouds decrease (new to me). (Decrease in cloud cover increased surface exposure to suns radiation and heats the earth more.) The report CERES 20 years 2  also found correlation to Water vapor, trace gases, surface albedo, as well as clouds. Both of these reports express doubts on the current understanding of climate change and make recommendation to further understand what is causing cloud cover to change.
    While this new data is interesting and worth following up on it is still very noisy (low R^2) and another 20 years would be better.


    I recognize that AGH global warming would promote other forcing including reduce clouds, reduced ice, reduced snow cover all exposing more surface to direct rays of the sun. Other man-made albedo changes can do the same thing. Here are two examples that may relate to the new papers.
    Let’s start with the “heat island effect”, UHI. While the global warming from UHI’s lower albedo is small it does have observable effect on cloud formation, CERES 20 years 2.



    “Figure 3
    Attribution of Clouds and the Earth's Radiant Energy System net top-of-atmosphere flux trends for 2002/09–2020/03. Shown are trends due to changes in (a) clouds, (b) surface, (c) temperature, (d) combined contributions from trace gases and solar irradiance (labeled as “Other”), (e) water vapor, and (f) aerosols. Positive trends correspond to heat gain and negative to loss. Stippled areas fall outside the 5%–95% confidence interval. Numbers in parentheses correspond to global trends and 5%–95% confidence intervals in W m−2 decade−1.”



    When air rises from a UHI it is hotter than the incoming air without a source of moisture to saturate it; so, it leaves as dryer air. This air generally rises and moves to the east. Look at figure 3 (a) and see the lower cloud formation change off the coast of east USA, Tokyo, and downwind Europe. With time (1880-2021) the UHI does not get hotter but it gets bigger thus the volume of low moisture air gets bigger. I am not going to argue the significances of the albedo part of UHI other than to recognize it is lower than 1 W/m^2 but not zero. What UHI is not given credit for is what happens downwind to this hotter low humidity air. Does it cool the ocean, reduce the snow line, melt ice, or reduce the cloud cover down wind, since this hot dry air should rise the clouds should be the first target.  I can also see a chain of events: Hot low moisture air (from AGHs, UHIs, or other land changes) rises and go downwind, reduces cloud cover, over water the sun heats the ocean, the hotter ocean currents circulate to the poles, and melt some ice.
    I’ll leave the quantification of this observable (figure 3 (a)) new (to me) correlation to others. A new UHI contribution to GW will be the albedo effect + the lower cloud effect + any other.



    Second, is land use changes such as forest to crop or pasture land or grass land to crop land.  Albedo decrease in grass land to crop land change is documented in Grass to Crops.   Forest to crop land change increase in albedo is documented in Forest to Crops.  Over 205 years the paper Global albedo study  calculates that all the pluses and minuses add up to little change in albedo from land use changes. It is assumed (by me) that decreased albedo of a parcel of land means an increase in temperature and vs/vs. The study Amazonia Forest to Crops shows that increasing albedo does not always mean cooler temps. This report shows that when rain forest was replaced with crop land that the temperature increased, the rain decreased, and the cloud cover decreased. The Figure 3 (e) above shows bright red spot for “water vapor” (I assume that is change to lower humidity) in Amazonia. This is not an uncommon effect from replacing forest with crop or pasture land. The report Forest study  observes that forests vs crop/pasture conversion gets warmer as the conversion gets south of 35’N latitude.



    This unintuitive (to me) observation that an increase in albedo does not always result in a decrease in temperature can be explained by moisture. The resulting temperature depends on a constant enthalpy (total heat in the air= gases + moisture). Enthalpy is usually determined by the albedo (higher albedo lower enthalpy vs/vs); therefore, land exposed to the same albedo (enthalpy) can have a wide range of temperatures depending on the moisture (relative humidity) of the albedo (enthalpy). This relationship has been captured in a psychrometric chart,


     



    (Sorry for the poor quality of this chart)
    Example of a rain forest conversion to crop land: Start out with a rain forest at 25’C (bottom scale) go straight up to 90% humidity curve; this is our hot humid rain forest. If we convert this rain forest to crop land with a higher albedo, we move to a lower enthalpy line (anyone will do). The constant enthalpy line run diagonal (upper left to lower right). If the moisture is maintained at 90% the temperature will drop as expected for the higher albedo. Following the same enthalpy line (same albedo) go to a lower humidity curve that may result (and does in Amazonia) and one will see the temperature will increase (even to above the starting rainforest temperature at very low humidity).
    A concern is how NASA and the IPCC pair surface temperature data with relative humidity and albedo. The three all connected in enthalpy. A misunderstanding of climate change could occur if Amazonian (rain forest to crop land) high albedo, high temperature, lower humidity type data was included in correlations with Canadian (forest to crop land) lower albedo, cooler temperatures, high humidity, type data. Does anyone know if this has been looked at? The report CERES 20 years 1 has looked at ocean enthalpy correlations. I have not seen any land enthalpy data.

  • It's albedo

    blaisct at 07:22 AM on 9 December, 2021

    The data presented earlier in this thread has been updated in document Earth's Albedo 1998–2017 as Measured From Earthshine


    [Link]


    albedo data from earth shine and CERES


    Figure 3
    “Earthshine annual mean albedo anomalies 1998–2017 expressed as reflected flux in . The error bars are shown as a shaded gray area and the dashed black line shows a linear fit to the Earthshine annual reflected energy flux anomalies. The CERES annual albedo anomalies 2001–2019, also expressed in , are shown in blue. A linear fit to the CERES data (2001–2019) is shown with a blue dashed line. Average error bars for CERES measurements are of the order of 0.2 .”



    This new data shows a good agreement between earth shine data and CERES satellite data one can also add the earth’s temperature for this time to this graph and fined good agreement with the albedo (+0.4'C or 0.8 W/m^2 in 20 years). The implication is that the earths albedo change can account for all the temperature rise over this time period. The document suggest that this albedo change was possibly due to reduced cloud cover. Leaving the question what caused the reduced cloud cover.


     

  • CO2 lags temperature

    MA Rodger at 01:53 AM on 13 November, 2021

    Yoshi @635,


    I fear you misinterpret the 90% figure. As described by Skakun et al (2012) (& discussed in this SkS post), the 90% is not the percentage of warming coming out of an ice age that is caused by CO2. It is the percentage when increases in CO2 occur prior to increases in global temperature.


    The actual post-ice-age warming resulting from increased CO2 is a portion of the GHG warming (which also includes methane). The GHG warming is given as 37% of the total in this CarbonBrief explainer. (The remainder is given as 50% ice albedo & 13% dust & aerosols.) The actual CO2 forcing is about 2.5Wm^-2.


    The cooling of the world that leads to a glacial maximum is much slower than the warming of the world that leads to an interglacial. The cooling begins with increased albedo in high northern latitudes as they lose sunlight through the orbital wobbles.


    The warming is quicker because it takes less time to melt down an ice sheet than it does to build it up. As with the warming, CO2 reacts to this cooling and increases the effect.

  • It's the sun

    cph at 21:57 PM on 11 November, 2021

     


    Diagram showing the monthly fluctuations in total global cloud cover since July 1983. During the observation period, the total amount of clouds fluctuated from about 69 percent in 1987 to about 64 percent in 2000. The annual variation in cloud cover follows the annual variation in atmospheric water vapor content, which presumably reflects the asymmetrical distribution of land and ocean on planet Earth.


     


    Within the still short period of satellite cloud cover observations, global cloud cover reached a maximum of about 69 percent in 1987 and a minimum of about 64 percent in 2000 (see diagram above), a decrease of about 5 percent. This decrease corresponds roughly to a net change in radiation of around 0.9 W / m2 within a period of only 13 years, which can be compared with the total net change estimated by the IPCC 2007 report from 1750 to 2006 of 1.6 W / m2 for all climate drivers including greenhouse gas emissions from fossil fuel burning(cooresponds to your mentioned 2,5-3W/m² in 2021). These observations leave little doubt that cloud cover variations can have a profound impact on global climate and meteorology on almost every time scale considered.


    The total reflectance (albedo) of the planet earth is about 30 percent, which means that about 30 percent of the incident short-wave solar radiation is reflected back into space. If all the clouds were removed, the global albedo would drop to around 15 percent and the short-wave energy available to warm the planet's surface would increase from 239 W / m2 to 288 W / m2 (Hartmann 1994). However, long-wave radiation would also be affected, which emits 266 W / m2 into space compared to the current 234 W / m2 (Hartmann 1994). The net effect of removing all clouds would therefore still be an increase in net radiation of around 17 W / m2. So the global cloud cover has a significant overall cooling effect on the planet, although the net effect of high and low clouds is opposite.


    HK: - "but also through its warming effect through its strong greenhouse effect, which is the most important of all positive (reinforcing) feedbacks on a global level."


    Wild, M., Hakuba, M.Z., Folini, D. et al. The cloud-free global energy balance and inferred cloud radiative effects: an assessment based on direct observations and climate models. Clim Dyn 52, 4787-4812 (2019).  https://link.springer.com/article/10.1007%2Fs00382-018-4413-y
    According to the current status, the net radiation effect of clouds is -19W / m² (Wild 2019) and corresponds very well with + 0.9W / m² per 5% less cloud cover.


     


    High levels of global cloud cover are associated with low global temperatures, demonstrating the cooling effect of clouds.                        A simple linear fit model suggests that a 1 percent increase in global cloud cover corresponds to a global temperature decrease                        of about 0.07 ° C.

  • It's the sun

    HK at 06:44 AM on 10 November, 2021

    My point in #1292 was that the 0.5 W/m2 of forcing from clouds and snow/ice is small compared to the overall net forcing over the last 150 years or so and that the albedo change brought up by you is at least partly a direct consequence of the warming, i.e., one of the positive feedbacks.


    However, I will admit that clouds and humidity are complex and can be influenced by other factors in addition to the direct result of man-made greenhouse gases. Desertification and deforestation in general and especially cutting down tropical rainforests can have a profound impact on the local hydrological cycle, changing humidity, cloud cover, rainfall and run-off and thus have an impact on the local temperature as well. So yes, man-made climate change isn't only about the greenhouse effect and the warming caused by it, but it's definitely the most important part of it on a global scale.
    It's also worth noting that even if the relative humidity seems to have decreased somewhat for the reasons explained here, the absolute or specific humidity has in fact increased, just as expected in a warming world.


    Specific humidity


     



    Water has an impact on the temperature not only via its removal of latent heat through evaporation – which has a local cooling impact – but also through its warming impact via its strong greenhouse effect, which is the most important of all the positive (amplifying) feedbacks on a global scale.

  • It's the sun

    cph at 22:01 PM on 9 November, 2021

    HK@1292 - "BTW, if clouds and snow/ice changed by themselves and not as a feedback to warming caused by GHGs, we wouldn't get a cooling stratosphere..."


    --- I did not understand your last sentence. I am of the opinion that, for example, a changed cloud albedo cannot be explained by a rise in temperature alone. Changes and anomalies in global mean cloud cover can also be caused by fewer (sulfate) aerosols or expanding deserts (dry regions become drier).


    https://www.carbonbrief.org/satellite-data-reveals-impact-of-warming-on-global-water-cycle


    Timeseries for evapotranspiration (top), precipitation (second from top), discharge (second from bottom) and change in ground water storage (bottom) over 2003-19.


    Evaporation increases by + 2.3 mm / year, which is not fully compensated for by increased precipitation of + 1 mm / year. A decreasing runoff through the rivers of -1.01 mm / year and a falling groundwater level of -0.75 mm / year quantify the drainage of the continents. This drainage (through drained bogs, wetlands, groundwater, aquifers, canalization of rivers and a constantly growing sealing of urban areas) is just as man-made as the CO² emissions, rising temperatures and the resulting higher evaporation. Too little H²O in desert regions and the earth's atmosphere, which in summer extend through droughts up to the Arctic Circle, are a temperature driver. Too much CO² is just as warming as too little H²O. Less evapotranspiration -> less cloud albedo -> higher incoming radiation energy and record temperatures on the earth's surface -> even faster drying out with even higher temperatures - imho, similar to the ice-snow albedo, form a vicious circle.


    The authors estimate a "statistically significant" increase in evapotranspiration of around 10% above the long-term mean (corresponds to a temperature increase over land areas of ~ + 1.44 ° C). During the same period, precipitation only increased by 3% and global river runoff decreased by 6%.


    ---


    What is noticeable here is a simultaneous decrease in relative humidity and cloudiness, which certainly correlates with a general increase in the number of hours of sunshine.


    time series sunshine hours germany 1951-2020


     


    Global time series of annual average relative humidity for the land (green line), ocean (blue) and global average (dark blue), relative to 1981-2010.

  • SkS Analogy 25 - Emissions vs Accumulation

    cph at 08:33 AM on 9 November, 2021

    michael sweet@19 - "It appears that large scale irrigation lowers the temperature a little. This has been known for a long time..."


    -— What you call a wild plan - I call it water cooling. It is much more efficient than air cooling and is generally described in climate science as the Bowen ratio. While it is ~ 0.1 over tropical oceans and rainforests, it reaches ~ 10 in deserts.


    Decreasing surface BR plays a major role in the surface energy budget. It is estimated that the cloud feedback may increase albedo by 0.13 and reduce Rnet by 25 W m−2 in summer over agricultural land.



    ms: - " The suggestion of piping enourmous volumes of water to the desert is absurd. / ...all available water is already used for irrigation and no additional water remains. "


    -— I suggested a water transfer without pipeline ! Absurd - is to think that you only have to turn on the tap to get water. / Perhaps in the Central Valley people should start thinking about using the water retention measures I described above. - In principle a simple, worldwide request to politics, agriculture, industry but also to private persons to build up extensive water reserves wherever & whenever possible in order to use them generously in plant growth, evaporation, clouds and "water cooling" during periods of drought in spring and summer.

  • It's the sun

    HK at 01:05 AM on 7 November, 2021

    "Explained by the cloud and snow / ice albedo that has decreased in the last few decades (0,5W/m² which is a lot)."


     


    The net forcing from the preindustrial period when counting both the positive forcing from the greenhouse gases and the negative forcing from man-made aerosols is now roughly 2.5–3 W/m².
    Changes in clouds and the snow/ice albedo are positive feedbacks amplifying that warming. The most important and fastest of those is the water vapour feedback which roughly doubles the initial warming.


    BTW, if clouds and snow/ice changed by themselves and not as a feedback to warming caused by GHGs, we wouldn't get a cooling stratosphere or more warming in winter than summer at high northern latitudes.

  • It's the sun

    cph at 00:09 AM on 7 November, 2021

    HK@1290 -


    "The only explanation making sense is that the Earth gives off less heat to space."


    --- Another additional explanation would be the fact, that the earth absorbs more short-wave solar energy from space, although the solar constant(1360,5W/m²) tends to decrease actually.


    Explained by the cloud and snow / ice albedo that has decreased in the last few decades (0,5W/m² which is a lot).


     

  • SkS Analogy 25 - Emissions vs Accumulation

    Jim Eager at 07:14 AM on 3 November, 2021

    Are you deliberately missing the point? It has nothing to do with the radiative forcing of H2O, it has to do with the fact that you can not directly increase the amount of water vapour in the atmosphere without first warming the atmosphere, otherwise the added H2O will simply condense out.


    Thought experiment: Remove all other greenhouse gasses from the atmosphere except water vapour. What will happen?


    The greenhouse effect will be reduced, cooling the surface and atmosphere. As a result the atmosphere will be able to hold less water vapour, so it, too, will be reduced by condensation and precipitation, thereby further reducing the greenhouse effect. As a result the atmosphere will be able to hold even less H2O. And so on. Pretty soon this will effect surface albedo as the precipitated water freezes into snow and ice, which will reflect more sunlight and reduce temperature still further.


    The point is you can not directly increase H2O, which means it can not be a driver of greenhouse warming, only contribute to it as a feedback.


    As for referring to Wikipedia as an authority on anything, you're joking, right?

  • SkS Analogy 25 - Emissions vs Accumulation

    Jim Eager at 01:13 AM on 3 November, 2021

    cph: "what do you think of H2O as the most strongest one"


    While H2O is by far the main greenhouse gas, it is condensible at normal Earth temperatures so it can only act as a feedback, not as a driver or forcing. Why? To increase the amount of water vapor in the atmosphere the atmosphere must first warm by some other means, either by an increase in incoming sunlight, a change in surface albedo, or by an increase in CO2 and/or CH4 in the atmosphere, neither of which are condensible at normal Earth temperatures.


    cph: "Cows and sheep livestock generate more greenhouse gases as measured in CO2 equivalents than the entire transportation sector."


    This is shear nonsenese perpetuated by strident vegans who have hijacked climate change to further their own agenda. See the sector graph MA Roger posted. One could commit the same slight of hand by combining portions of the mining, smelting, petrochemical, manufacturing, and construction sectors related to the tranport system into the transportation total. It is fundamentally dishonest to do that with livestock but not with other sectors, and it renders sector attribution meaningless.

  • It's albedo

    MA Rodger at 01:40 AM on 26 October, 2021

    I was reluctant to look into the values of Cloud Radiative Effect by location as up-thread the idea that added cloud & associated albedo came without added warming from water vapour seemed to be too difficult to accept by an insistent commenter and I wasn't sure how supportiive the result would turn out to be.


    However, Calisto et al (2014) does provide in its Fig 7 the positive and negative components of CRE by latitude for both Land & Ocean and they can be easilyare here adapted to show net CRE as in the following graphic (assuming the graphic is visible to others when I link to it). The net CRE by latitude is the gap between the bold red trace & the green/blue trace in the upper panels.


    Calisto et al (014) fig 7 adapted

  • It's albedo

    Bob Loblaw at 04:49 AM on 20 September, 2021

    I have no idea why the "hot link" problem occurs. When a simple click didn't get me to the graph, I tried copying the URL. When that worked, I thought I'd let others know.


    The sum of the trends isn't that far off 0:The balance is ET = Pr - Q - dS/dt, or 2.30 = 1.00 + 1.01 + 0.75 ==> 2.30 = 2.76, so only off by 0.46.


    (Pr, Q, and dS/dt are defined in the figure in MAR's comment.)


    I was able to download the Pascolini-Campbell et al paper through work. They do discuss the uncertainty in trends. On p 544, they say:



    "Propagated uncertainty in the trend is greatest for Pr (±0.41 mm yr−1 ), followed by Q (±0.32 mm yr −1), and smallest for dS/dt (±0.05 mm yr −1). This leads to a bounded ET trend estimate of 2.30 ± 0.52 mm yr−1 (determined by summing the square of the error in the trend of each component). The fractional uncertainty from Pr is 61%, 38% from Q and 1% from dS/dt. From this analysis it follows that the ET trend is positive and significant in light of the propagated error, and ranges from 1.78 mm yr−1 to 2.82 mm yr−1."



    This is getting off-topic for albedo, though.

  • It's albedo

    MA Rodger at 05:23 AM on 18 September, 2021

    The commenter @97 is no-longer a participant here but as this response to his comment @97 is albedo-stuff, I hope the moderators will allow it.


    ☻ Concerning the spectrum of reflected light in earthshine:- @97, the objection was to Woolf et al (2004) using an arbitrary ordinate scale on their Fig 1 (shown @96) rather than Wm^-2. Addressing this objection (although Woolf et al Fig 2 should have sufficed as it shows a roughly constant % albedo with wavelength), below is a graph of spectrum for wavelengths 0.25 to 6.5 microns (so into the UV) with a Wm^-2 ordinate scale. (Woolf et al above shows the spectrum 0.48 to 0.92 microns, so into the IR.)


    albedo spectrum


    ☻ Concerning Wild et al's -19Wm^-2 clear-sky radiation:- Indeed, as commented @97, it is "visa versa"  @96 as "cooling" was written in error and should have been "warming" from clear-sky relative to all-sky.


    Do note that the cooling from an AGW-induced decrease in albedo is greatly due to the reduction of tropical marine cloud. AR6 provides a better assessment of such cloud today that allows AR6 to state that "A net negative cloud feedback is very unlikely" with a potential range of -10Wm^-2ºC^-1 to +9.4Wm^-2ºC^-1 ['very likely' =1.67sd]. (Although half the range given in AR5, these remain broad confidence intervals.)


    Yet the -19Wm^-2 result from Wild et al (2019) was not misunderstood. The value is saying that the net energy balance under clear skys is -19Wm^-2 relative to the global average. (Note a coincidental -19Wm^-2 is also given by Wild et al for Land relative to Global.)
    It doesn't follow that a reduction of clear-sky conditions would result in a comenserate cooling of the planet (just as an increase in the land area of the planet would not be expected to increase planetary cooling). It is not so simple.
    Note what Wild et al consider their finding would be useful for:- "To better constrain (global climate models from CMIP5), we established new clear-sky reference climatologies." There is no mention of geo-engineering. (And note that if it were, the net planetary cooling would be -19Wm^-2 for the extra cloud and a further -19Wm^-2 for the loss of clear sky - this assuming a 50% global cloud fraction.) However, the impact of altering the global level of clear-sky conditions would depend entirely on the particulars of the alteration.
    Indeed, consider the cloud-effect in its totality. If the models take all the clouds out but keep everything the same, the GH-effect is diminished by about 15%. This would suggest increased cloud warms (and so does not cool,) a warming with a back-of-fag-packet global value of [33ºC GH-effect x 3.7Wm^-2/ºC x 15% =] +18Wm^-2. So +ve and not -ve. An interesting result.


    ☻ Finally, the mistake within the annotations of Fig3 of Pascolini-Campbell et al (2021) - It a trivial mistake (that the value of 2.3mm/yr in Fig3a should be 2.3mm/yr/yr and likewise elsewhere) as the mistake is quite evident. Simply look at the regression line. The graphed regression line rises from an anomaly of -18mm/yr in 2003.0 to +21mm/yr in 2020.0, so a rise of 39mm/yr over the 17-year period graphed = 2.3mm/yr/yr.

  • It's albedo

    coolmaster at 15:37 PM on 17 September, 2021

    @96


    MA Rodger: you state that "albedo is ... depends primarily on the wavelength of the light that hits the body/molecule." This is not correct. The reflected light is pretty-much independent of wavelength being no more than "bluish". The spectrum of reflected light is thus not significantly different from the spectrum of sunlight.


    coolmaster: I'm not sure if you know that e.g. plants are green (wavelength = ~ 550nm), a tomato red (~ 650nm) and blueberries (~ 450nm) blue when illuminated by sunlight with a full spectrum.


    Illuminated by a full spectrum (white), the objects appear to your eyes & brain in more or less monochrome light. So - many of the incident wavelengths are absorbed and only single colors are reflected.
    A snow surface is white and has a high albedo because all wavelengths are reflected in the range that is visible - nevertheless, snow absorbs very strongly in the long-wave range of IR radiation.


    What you describe as "bluish" is the Raleigh scatter.
    This has absolutely nothing to do with absorption, relative reflection and albedo.


    Your posted graph shows the spectral properties of the light emanating from the earth - and not the energy content of sunlight, that matters in an energy balance.
    Without having read the article - I guess you will hardly find the unit W / m², which is the important one for the radiation budget of the earth. So please don't mix it all up here. (MOD)


    MA Rodger: The TOA radiation balance under clear sky conditions averaged globally by Wild (2019) shows 19Wm^-2 more cooling than his all-sky average.
    coolmaster: No you are utterly wrong - it is vice versa.


    Or do you feel yourself cooler in sun under clear sky - and feel heat when a cloud covers the sun ????


    The radiation net effect of clouds and water vapor (CRE = -19W / m²) You still seem to confuse CRE with the atmospheric feedback of the clouds, which consists in the fact that with increasing temperature less cloud cover, changed lapse rate and optical depth are determined (+ 0.42Wm-2 ° C-1).    Earth - is - loosing - the clouds !


    MA Rodger: ☻ And to correct your bold assertions @94 / Your own derivation of a greatly different value of 344km^3/yr uses solely Fig 3a of the former paper which gives an annual rate of increase as 2.3mm/yr (it should actually be 2.3mm/yr/yr)???? and for the 16-year period the increase would be thus 5,500km^3/yr, in the circumstance not a significant difference from 7,000km^3/yr.


    coolmaster: 1500km³/yr is more than I suggested to retain.


    www.carbonbrief.org/satellite-data-reveals-impact-of-warming-on-global-water-cycle


    Can you give us just a reference or a page in the www. quote where the unit mm / yr / yr is used ???? You should then definitely get in touch with Ms. Madeleine Pascolini-Campbell and explain to her that she was mistaken by a factor of ~20.


    After all, her work and GRACE-FO are regarded worldwide as one of the most important findings of the last few years. So if you know better - go ahead ... Your pocket calculator with the built-in joker must have been very expensive.

  • It's albedo

    MA Rodger at 21:30 PM on 16 September, 2021

    coolmaster @94+,
    Trying to keep this on-topic for the thread (and I would have considered transferring this interchange on what is geo-engineering to another thread if it had a chance of being usefully continued), some Albedo issues which you raise.


    ☻ Firstly, within the deleted comment @95 (still visible to commenters), you state that "albedo is ... depends primarily on the wavelength of the light that hits the body/molecule." This is not correct. The reflected light is pretty-much independent of wavelength being no more than "bluish". The spectrum of reflected light is thus not significantly different from the spectrum of sunlight as Fig1 of Woolf et al (2002) demonstrates.


    Woolf et at (2002) Fig 1


    ☻ Your annotated graphics @71 are probably taking the simplisitic calculations a step-or-two too far.
    Want we can say from Wild (2014, 2019) is that Land Cloud albedo is shown as 19.7% with Land Surface albedo shown as 26.1%. Likewise Ocean Cloud albedo is given as 23.1% and Surface albedo as 8.1%.
    The TOA radiation balance under clear sky conditions averaged globally by Wild (2019) shows 19Wm^-2 more cooling than his all-sky average. Yet this result does not mean that cloud and its resulting albedo is overall a cooling influence. Cloud is well-known to cool if low and to warm if high and the latitude is also important. The usual climatological consideration is whether today cloud presents a positive or negative feedback to a warming world, the present understanding being that it is very likely positive, a position reinforced by recent work (eg Ceppi & Nowack (2021) [Abstract] (@94 you cite resumably IPCC AR6 with a similar finding.)

    We have up-thread shown very large increases in anthropogenic water 'use' on land and measured increases in evaporation over land. Thus to suggest an increase in evaopration over land would result in a higher cloud fraction and a strong cooling based solely on Wild's 19Wm^-2 is based on very shaky ground.


    And the following back-of-envelope calculations suggest there would not be cooling but warming.


    We see from Fig 2 Wild (2014) an all-sky Land Cloud albedo of 64Wm^-2. If cloud albedo were increased 1% that would pro rata present a global climate forcing of -0.19 Wm^-2 cloud albedo but with a loss of +0.05 Wm^-2 surface albedo. There is also reduced OLR cooling of +0.08 Wm^-2 pro rata suggested in Wild (2019) Fig14 and a water vapour forcing from the 1% increased humidity over land of roughly +0.12 Wm^-2. This would suggest a net warming from a 1% increase in Land evaporation of +0.06 Wm^-2, this a warming climate forcing larger than AGW.


    ☻ And to correct your bold assertions @94 concerning arithmetic. The 10% percent increase in land evaporation 2003-19 reported by Pascolini-Campbell et al (2021) multiplied by the 69,000/yr (+/-10%) land evaporation given by Abbott et al (2019) yields the 2003-19 increase of 7,000km^3/yr I present @93 (along with the references). The other values alongside which you object to are similarly derived.
    Your own derivation of a greatly different value of 344km^3/yr uses solely Fig 3a of the former paper which gives an annual rate of increase as 2.3mm/yr (it should actually be 2.3mm/yr/yr) and for the 16-year period the increase would be thus 5,500km^3/yr, in the circumstance not a significant difference from 7,000km^3/yr.

  • It's albedo

    coolmaster at 23:46 PM on 13 September, 2021

    @GPWayne:


    "We know the planet is warming, and that human agency is causing it. What we cannot say yet is how climate change is affecting albedo, how it might be affected in the future, and what contribution to climate change - positive or negative - it may make."


    coolmaster: The albedo is relative ... and depends primarily on the wavelength of the light that hits the body/molecule. We should therefore always specify a wavelength range for the albedo. Otherwise, strictly speaking, the entire incoming spectrum of the sun ( UVC140nm up to Micro waves10cm) is decisive. This relativity to the albedo is particularly important for an element as widespread worldwide as H²O. I.e. ice and snow with an albedo of up to 0,9 in the visible range(380-780nm) has an albedo in the micro wave range of only < 0,1.


    Albedo of the earth ist 0,3 because absorbtion is 0,7(0,5 on the surface + 0,2 in the atmosphere) --> so the atmosphere has an albedo. Higher concentrations of GHG specially CO² is lowering the albedo of the atmosphere and is thus increasing temperature. We could always increase the albedo elsewhere: clouds, white color in the outdoor area or lighter field crops through foliar fertilization with light clays are just a few of the many possibilities.


    The temperature of the earth's surface is globally determined by the radiation balance, the radiation budget. This records the interaction between absorption and reflection as well as re-emission and scattering.
    But no matter which albedo you are looking at, whether short or long wave - a higher albedo can never cause a rise in temperature or energy. Conversely, every falling albedo increases temperatures or energy on earth.
    So I suggest that you update the last sentence of your basic rebuttal.


    @Moderation response: "last warning"


    In my last comment, which you would like to see in the slr section, the word albedo appears 3 times - the words clouds and cloud cover even more often. You should also warn others, who do exactly the same(i.e. MAR,BL).
    The inseparable connection between albedo - clouds - water and SLR was invented by an immovable mover (Aristotle's definition of God) ! not me !
    I don't want to discuss religion here, if only because I don't belong to any official religious community and because my religion is art. For me, climate science is a discipline, just like painting, sculpture, dance, music, and theater, etc.


    Nevertheless, I noticed that there once was a man who said he wanted to save the world. Among other things, because he supposedly could move over the water ...
    I also want to save the world ... and move (spiritually & physically) over the water.


    If you don't like my holistic, alternative climate protection strategy, which lowers sea level rise and earth temperatures - I can't change it, but I can't understand it either. In my opiniont it is the very last opportunity for you, your readers, commentators, your descendants, and the rest of creation to escape from climate hell (as long as anybody presents a much better, faster or cheaper concept.)


    That was my last warning to you...


     

  • It's albedo

    coolmaster at 10:47 AM on 13 September, 2021

    MA Rodger93:


    MAR: "Your proposed grand scheme seems to be assuming atmospheric water can increase by 0.001335M km^3 annualy, or a 10% annual increase."
    No - I never ever assumed, wrote or thought about that I plan or can increase atmospheric water by 1335km³ annualy.


    You are making a very similar mistake as Prof. Stefan Rahmstorf from PIK in Potsdam in response to my comment in another climate forum.


    https://www.realclimate.org/index.php/archives/2021/08/sea-level-in-the-ipcc-6th-assessment-report-ar6/#comment-794653


    Your mistake is probably that you have not read my posts with due attention, even though they are kept very simple and straightforward.
    An increase in atmospheric water by 10% / year would mean that, according to the CCF, earth temperatures rise by approx. 1.4 ° C per year. A state of the climate which means certain death for all life on earth.


    So you also completely misunderstood me.


    My climate protection strategy would like to take the volume of 3.7mm SLR(1335km³) from the global rivers discharge when their water levels are sufficient(&clean) or even specially in flood events after rain- !!! to store it in soil moisture and groundwater over the land mass.
    In principle a simple, seasonal storage of retained river water also to adapt to droughts and floods.


    In dry seasons, this water will be mainly evaporated from agriculture, but also the before mentioned “amunas” of the old inca culture and their water management are a perfect way to rewet forests & moors.


    hidraulicainca.com/lima/sistema-hidraulico-amunas/


    This in turn ensures an increasing relative (and specific) humidity and additional cloud formation over land in a regional drought season.


    After an average of ~8.5 days in the atmosphere it will return – even with a relatively high probability – as precipitation over another land area. There will be a multiplier effect that increase together with soil moisture and evaporation rate (wet regions become wetter).


    As a result, the water cycle over the land areas is intensified by ~ 1-1,5% and thus the increasing size of the annual mean cloud cover over land areas leads to a higher albedo & CRE, which I estimate to be at least a cooling RF of ~ -0.2W/m² / year.
    A really cooling, additional radiative forcing, which, in my opinion, can more than compensate for the current annual radiative forcing caused by CO² .


    A holistic, functioning climate protection strategy,(stopping SLR AND global temperature rise & adaptation to droughts and floods) which works alternatively and independently of the reduction in CO² emissions, which only promises to stop the temperatures rise perhaps after ~ 2070 (if we as humanity can reduce emissions immediately – which I personally do not believe)


    In the latest IPCC report / WG1 Chapter 7.4.2.4.3, the positive feedback of the cloud cover on an atmosphere warmer by 1 ° C is given with +0.42W m-2 ° C-1.


    We are slowly but steadily losing not only areas of ice and snow albedo, but also the clouds albedo due to decreasing global mean cloud cover and higher lapse rate.
    The cooling CRE with ~-19W m-2 (chapter 7.2.1. in the same report) should decrease accordingly.


    The slower warming of the oceans means that there has not been enough moisture evaporated into – and then held in – the air above the oceans to keep pace with the rising temperatures over land. This means that the air is not as saturated as it was and – as the chart below shows – relative humidity has decreased, desertification is spreading rapidly mainly caused by human activities.
    Dryness is a temperature driver and cloud killer.


    https://www.carbonbrief.org/wp-content/uploads/2020/11/Global-time-series-of-annual-average-relative-humidity-for-the-land-ocean-and-global-average-relative-to-1981-2010.jpg



    That is why I (as an artist - not a climate scientist) think it's a good idea to create additional “artificial” clouds by additional artificial irrigation retained by river discharge from the superfluous water of the oceans.


    ---


    MAR: but the reported 10% increase in evaporation rate 2003-19 over land equates to some 7,000km^3/y while the reported 3% increase in rainfall equates to 3,300km^3/y and the decrease in direct discharge from land to ocean a further 3,000km^3/y.


    This suggests your grand scheme wouldn't make a ha'p'orth of difference. Evaporation over land is shown to have increased five-time the amount you propose yet AGW and SLR continued apace.


    coolmaster: ???


    360.57M km² ocean area * 3.7mm SLR = 1334.1km³ water = 8.93mm above the land area.


    149.43M km² land area * 2.3L / m² increasing evaporation per year = 343.689km³ water.


    * 1L / m² increasing precipitation per year = 149.43km³
    * -1.01L decreasing runoff through the rivers per year = -150.92km³
    * -0.75L decreasing groundwater level per year = -112.07km³


    Your calculator probably has a built-in joker.
    And if you are holding a PhD, you should hand it over (to me ?) as soon as possible.

  • It's albedo

    MA Rodger at 21:56 PM on 12 September, 2021

    coolmaster @92,


    Your final paragraph is packed full of unsupported assertions which you say will result from your grand scheme of annually diverting 1,335km^3/y of water that would otherwise discharge into the oceans and thus radically increase global albedo through increased cloud. The "unsupported" nature of your assertions is easily demonstrated with the two references you provide.


    ♣ The graphic you present is from Wikithing but is adapted from Abbott et al (2019) 'Human domination of the global water cycle absent from depictions and perceptions'  who provide the numbers in their Fig 3. Relevant to your grand scheme is the size of the various global water reservoirs. The giant reservoir is of course the oceans which hold 1,340M km^3. Next is ice with 25M km^3 and surface/soil water with 23M km^3 while trailing along far behind is the atmosphere holding just 0.0125M km^3 water.


    Your proposed grand scheme seems to be assuming atmospheric water can increase by 0.001335M km^3 annualy, or a 10% annual increase. Note this 10% annual increase in atmospheric water would add to the GH-effect, perhaps by some 4Wm^-2 annually, so 100x stronger than today's AGW.


    ♣ The CarbonBrief reference describes Pascolini-Campbell et al (2021) 'A 10 per cent increase in global land evapotranspiration from 2003 to 2019' which is iteslf paywalled [Abstract] but the reported 10% increase in evaporation rate 2003-19 over land equates to some 7,000km^3/y while the reported 3% increase in rainfall equates to 3,300km^3/y and the decrease in direct discharge from land to ocean a further 3,000km^3/y.


    This suggests your grand scheme wouldn't make a ha'p'orth of difference. Evaporation over land is shown to have increased five-time the amount you propose yet AGW and SLR continued apace.

  • It's albedo

    Philippe Chantreau at 03:03 AM on 12 September, 2021

    I've followed this exchange somewhat distractedly, but now I'm noticing this from coolmaster when confronted with the lack of cooling that has happened from exactly the physical process he argues would cause it:


    "NO. The water consumption of civilization and agriculture has increased steadily with the population growth.
    Agriculture in particular, as the largest consumer, has already dangerously lowered and polluted the water table in many places. Consumption continues to rise and the switch to river and rainwater is actually inevitable."


    How does that constitute any kind of response? It is completely beside the point and has nothing to do with the initial argument that the retained water would promote cloudiness, change albedo and lower temperatures. From that point of view, where the water comes from is irrelevant. The fact remains that the cooling imagined by Coolmaster from the physical process he described has not happened.

  • It's albedo

    Bob Loblaw at 11:49 AM on 11 September, 2021

    coolmaster @ 82:


    Congratulations. Another comments policy violation. You can't find anything using Google? Maybe if you look at the Skeptical Science Team page, you will find some clues about my background and why your Google search failed.


    It is amusing that you complain about a lack of links or references, when you still have yet to provide a reference for your claim that local surface evaporation will lead to a 1% increase in cloud cover. Just in case you have forgetten it, here is your original claim again:



    This volume can be retained by a wide variety of measures before it flows into the oceans and converted into evaporation. - 9L / m² corresponds to ~ 1% of the average annual rainfall over land and should therefore create ~ 1% additional clouds over the land mass.



    You repeat a diagram previously linked to. Let's us try to find the evidence we seek in that diagram.



    • Cloud cover data? Yes, for three types (high, middle, and low).

    • Clear annual cycles, especially for middle and low.

    • Global total cloud cover? We don't see sums, but it is obvious that the low and middle cloud amounts are counter-cyclical... when one goes up, the other goes down. Less variation in high cloud. Could it be possible that these cloud types are responding differently to whatever the seasonal cycles are? Maybe there are changes in geographical distribution? Maybe differences between land and sea?

    • Trends over time? Yes, And different trends for different cloud types.


    Oh, there is that pesky cloud type issue again. Maybe it's actually important?


    Now, let's look for evaporation data, so we can finally verify the elusive "1% increase in evaporation causes 1% increase in clouds" story.


    Hmmm. I'm looking hard, but I don't see it.



    • I see "atmospheric water". Is that "evaporation"? I don't think so. I seem to remember that "evaporation" is a flux from the surface to the atmosphere, not the storage in the atmophere.

    • Are we looking at a system where increased evaporation is actually causing these cloud changes? I see no evidence of that.

    • Oh, wait. Coolmaster has pointed out that this graph shows "...clouds feedback during the last decades triggered by a warming atmosphere..." My mistake - I thought you were trying to show data that supported your grand theory.


    This is typical of what coolmaster has produced here: links to papers or diagrams, with no explanation as to how they are supposed to support his argument, leaving the reader to try to examine the paper or diagram in search of something only coolmaster sees. There is no "there" there.


    You seem to like the IPCC reports. Since you appear to have a copy of AR6, I'll skip linking to it. Maybe it has something to say about your grand theory that irrigation can increase evaporation and cool the planet.


    [search]
    [search]


    Oh, maybe this is it!



    Section 7.3.4.1 Land use.



    It mostly covers albedo changes for land, but the second last paragraph says: "The contribution of irrigation (mainly to low cloud amount) is assessed as –0.05 [–0.1 to 0.05] W m -2 for the historical period (Sherwood et al., 2018)."


    Hmmm. With those error bars, it's hard to tell if the effect is positive or negative. It's also the total effect attributable to all the increases in irrigated land over the historical period. If the -0.05 number is correct, would there be a linear response to more irrigated land, so that 100x the historical area would lead to -5W/m2 and offset the CO2 forcing? How much water is used each year for current irrigated land?


    That might give coolmaster a glimmer of hope. Why has he not presented this information before? Maybe the more detailed results in the reference the IPCC uses do not support coolmaster's grand theory? Maybe he just doesn't know what to look for?


    Maybe coolmaster will eventually provide us with the evidence we need, but I won't hold my breath.


     

  • It's albedo

    coolmaster at 09:19 AM on 10 September, 2021

    BL@78


    BL: you double-down on your claim of a strong cooling effect for clouds. Let's examine some actual science.


    I have already sent you the current science in this regard. The graphics for the global radiation balances all_sky, clear_sky, land & ocean were created and published by Prof. Dr. Martin Wild / ETH Zurich. He is a very nice person and lead author of the IPCC AR6 WGI Chapter 7: The Earth’s energy budget, climate feedbacks, and climate sensitivity. (Chapters 7.2.1 and 7.4.2.4.3 are relevant for our topic.)
    You will not find our topic much more actual and precise anywhere, and if you continue to have doubts about the strong cooling influence of clouds - you should contact with Prof. Dr. M. Wild directly.


    BL: summary diagrams are summary diagrams - not detailed models."
    You will surely see that a slr volume of 1335km³ / year has to be distributed globally and that I therefore use global, summarizing radiation balances.


    Using the posted information in the explanatory file on land use and irrigation,


    https://www.frontiersin.org/articles/10.3389/feart.2020.00245/full


    you also have the opportunity to observe my claims about irrigation, cloud formation, precipitation, temperature, radiative forcing etc. on a more regional level.


    BL: ...it condenses to form cloud, but this is not always the case. ...So will this "extra" moisture cause more clouds? Maybe. Maybe not.
    You have provided no scientific justification for this claim, or references to suitable scientific publications to support it. You are completely wrong here. You claim that there is some kind of rest room for water vapor in the atmosphere. Could you please prove that.
    99,999% of atmospheric water vapor will form a cloud before it return as precipitation. Dew e.g. is also considered to be a form of precipitation.


    BL: As a consequence of increasing evporation, the location where the evaporation occurs will also see less thermal energy transfer to the atmosphere, so temperatures are also affected.
    Yes Sir - that´s what I mean. More latent heat flux = less sensible(thermal as you say) heat flux. H²O in the air will form clouds - dry and hot air in the atmosphere will kill them. Soil and air temperatures will decrease - and that's exactly what I intend to do with my strategy. You should also know that the extra amount of 1% precipitation/irrigation/evaporation is planed to released predominantly in spring / summer allways into a relatively unsaturated, dry and hot clear_sky atmosphere, which most closely corresponds to a drought period or desert.


    Intensification of the global hydrological cycle is a robust feature of global warming, BUT at the same time, many land areas in the subtropics will experience drying at the surface AND in the atmosphere. This occurs due to a ! limited water availability ! in these regions, where the cloudiness is consequently expected to decrease.


    Your speculations about different clouds, with their different effects on the albedo and SW / LW radiation effects, are not conducive to the discussion and are unimportant for my assessments. In a dry, hot, sunny high pressure atmosphere, I guess at least that mostly convective fair-weather clouds or thunderclouds (cumulus or c.-nimbus) will arise.


    1% more precipitation / evaporation will not have a major impact on the general cloud pattern. The natural regional variability of the amount of precipitation is often 200mm or more between dry and humid years. Since 9mm more or less per year will regionally cause no noticeable changes in the cloud regime. Maybe there will be 3-4 rainy days/year instead of increasing hours of sunshine.
    BL: Coolmaster's diagrams are nice pictures that help illustrate a few aspects...
    Again - these diagrams are not mine. They are calculated by professionals of IPCC experts. You have no clue about the difference between water- & air cooling, heat capacity & efficiency. That's your problem - not mine.

  • It's albedo

    coolmaster at 10:43 AM on 3 September, 2021

    Also in response to blaisct's comment #66 posted over on the Urban Heat Island discussion. 


     The albedo is relative ... and depends primarily on the wavelength of the light that hits the body. We should therefore always specify a wavelength range for Albedo. Otherwise, strictly speaking, the entire spectrum of the sun is decisive. This relativity to the albedo is particularly important for an element as widespread worldwide as H²O.


    As water vapor, it absorbs (28W / m²) largely only in the long-wave range and lets most of the visible light pass through.


    As liquid water on the surface, it absorbs long-wave and short-wave light very strongly, although as a cloud in the same aggregate state, finely distributed in the atmosphere, it again reflects a high proportion (-47W / m²) of the high-energy, short-wave radiation.


    As solid ice or snow on the surface, it reflects short-wave radiation as well as clouds. On the other hand, in the long-wave range it behaves like a black body and a layer of ice over the open sea isolates the one below
    warmer water and prevents it from emitting its heat radiation to the atmosphere and space which in turn relativizes the ice albedo effect.


    So @bleisct is not that wrong if he ascribes the Earth's albedo a major influence on global temperatures. The atmosphere (and every single component - including CO² molecules) also has an albedo if the solar spectrum is viewed holistically across all wavelength ranges and light refraction and transmission are taken into account as factors. Higher levels of GHG lower earth`s albedo by absorbing ~20% of radiation energy.


    @MA Rodger is right when he remarks that the cloud albedo ingeniously has the strongest albedo and the global albedo(change) is of very minor importance over urban areas.


      With a global mean surface albedo of 13.5% and net shortwave clear-sky flux of 287 Wm−2 at the TOA this results in a global mean clear-sky surface and atmospheric shortwave absorption of 214 and 73 Wm−2, respectively. From the newly-established diagrams of the global energy balance under clear-sky and all-sky conditions, we quantify the cloud radiative effects(CRE) not only at the TOA, but also within the atmosphere and at the surface.


    The cloud-free global energy balance and inferred cloud radiative effects


     Illustration of the magnitudes of the global mean shortwave, longwave and net (shortwave + longwave) cloud radiative effects (CRE) at the Top-of-Atmosphere (TOA), within the atmosphere and at the Earth’s surface, determined as differences between the respective all-sky and clear-sky radiation budgets presented in Fig. 14. Units Wm−2 


    When assessing the earth`s albedo, it`s also helpfull to have a look to the different radiation balances from land and sea and the fact that the cloud albedo is very closely interlinked with latent heat flux of evaporation in the radiation balance. 


    Do not confuse the strongly cooling CRE (-19W / m²) with the warming cloud radiative feedback CRF of ~ + 0.42Wm-2 ° C-1, which is a missing +RF in the above graphic by @Bob Loblaw as is also the radiative forcing of the ice Albedo effect.


    .The energy balance over land and oceans


    The energy balance over land and oceans

  • The new IPCC Report includes – get this, good news

    MA Rodger at 19:26 PM on 15 August, 2021

    anticorncob6 @1,


    The CO2 budgets quickly become very complicated and comparing them takes a little spade-work. Here is my simplistic take on it.


    That 2013 Carbon Budget you link to is quite a generous one, even though it is for +2ºC AGW. Its 1,000Gt(C) emissions budget or 3,664Gt(CO2) with an Airborne Fraction of 45% would yield [1,000 x 0.45 / 2.13 + 275ppm=] 486ppm atmospheric CO2 by 2090 (followed by negative emissions). Other Carbon Budgets, for instance the IPCC SR1.5 budget from 2018 set a budget at 432ppm for a 66% chance of avoiding +1.5ºC AGW, this with large negative emissions to follow the reaching of zero. (My assessment here using the simplistic Af=45%.) The AR6 SSP1-2.6  with its 2% annual reductions for a +2ºC AGW, again followed by negative emissions post 2075, I'd assess at something like 285Gt(C) post-2020 so 474ppm, not greatly less than that 2013 Budget you linked to @1. Mind the real wake-up numbers come from AR5 which put the 66%  +1.5ºC AGW at 417ppm.


    You mention the "positive feedbacks" and perhaps nigelj @2 should have added that land ice will continue melting away unless global temperatures are reduced, the worry being that Greenland will melt down (taking millennia) with warming somewhere between +1.0ºC & +2.0ºC AGW and with nothing to stop it once its summit drops down to warmer altitudes. And the stability of the West Antarctic ice is potentially even more sensitive to warming.


    Specific to being "positive feedbacks" (which melted ice fields are not unless they entirely disappear & so reduce albedo), the melting tundra is also a process which will continue for centuries without a return to a chillier climate. The size of such the feedback from melting tundra will depend on how hot we make it.


    Keeping the ice sheets intact and the tundra frozen is one of the more obvious reasons why limiting AGW to +1.5ºC is a sensible policy.

  • It's Urban Heat Island effect

    Bob Loblaw at 02:38 AM on 15 August, 2021

    blaisct:


    I have also replied to your post # 66 over on the Albedo Effect where Michael Sweet has responded.

  • It's albedo

    Bob Loblaw at 02:35 AM on 15 August, 2021

    Also in response to blaisct's comment #66 posted over on the Urban Heat Island discussion.


    Blaisct:


    You continue to make poor choices in the numbers and calculations that you are doing. Going over your latest effort by number:


    1. You continue to select an albedo for urban areas that is too low for anthropogenic surfaces, and you have failed to cite a reference for your value. In my comment # 64 on the Urban Heat Island discussion, I gave a reference to several artificial surface materials, all with albedo values that exceed the the value you have chosen. "Urban" areas are a mix of things like grass, roads, houses, etc. You would need to calculate how much of the surface is covered by each type, and work out an albedo for an "urban" area that way. If that is what you have done, you need to show your detailed calcuations on how you arrive at the 0.08 value.


    2. There are no assumptions in the 0.31 albedo value for the earth as a whole. That is based on satellite measurements, and includes reflection from the surface, clouds, clear atmosphere, etc. Note that the only part of the surface reflection that reaches space is the part that makes it back out through the atmosphere and cloud cover. To calculate this in a model (which is what you are trying to do), you need to account for spatial variations (and daily/seasonal cycles) of solar input, surface albedo, cloud cover, and atmospheric conditions.


    3 to 14. You continue to make unreasonable assumptions about the area that is undergoing a surface change, and how it relates to population. There is no reason to think that they are related through a simple proportion.


    15 to 20. You continue to make errors in converting solar output (1367 W/m^2 measured perpendicular to the sun's rays) to an areal average over the surface of the earth. As MIchael Sweet points out, there is a factor of 4 involved, not a factor of 2. I also mentioned this in my earlier comment. If you do not understand why this is the case, then it is difficult to see how you can expect to do any useful calculations. You also need to consider seasonal variations in solar radiation distribution and seasonal albedo.


    21. Converting radiative forcing to global temperature change involves looking at the top-of-atmosphere changes (what is seen from space), not surface changes alone. To properly incorporate surface changes into a calcuation, you need to use a much more complicated model of climate response to surface albedo changes.


    22. You still get a wildy incorrect answer, due to bad data input and bad assumptions.


    I have not bothered to follow the link to the Mark Healey document you mention. If that is the source you are getting your incorrect ideas from, then it is not worth bothering. The result you quote (that albedo changes can account for all the obsvered temperature rise) is completely inconsistent with the science.


    Over at RealClimate, they have recent posted several articles on the just-released IPCC reports. One of those summarizes 6 key results. In that post, they provide the following graph from the IPCC report, which shows the estimated temperature response due to a variety of factors over the last 100 to 150 years. "Land use reflection and irrigation" is the second-last bar on the right. Note that the calculated effect is minor cooling, not warming.


    RealClimate IPCC radiative forcings


    Michael Sweet's suggestion to read the IPCC reports is a good one. I often suggest that people start with the first 1990 report, as this covers a lot of the basic climate science principles in a manner that is easier to understand for the non-expert. In the 1990 report, they mention the Sagan et al paper I linked to in my first comment. Google Scholar can probably help you fnd a free copy.


    https://science.sciencemag.org/content/206/4425/1363.abstract

  • It's albedo

    michael sweet at 01:05 AM on 15 August, 2021

    blaisct:


    From here: It is generally a waste of time to do your own calculations.  The albedo of urban areas cannot have changed more that 50%.  The area of urban areas is less than 1% of the Earth's surface.  A 50% change in albedo in such a small area cannot have such a large effect.


    For starters you need to devide incoming solar radiation by 4 and not 2 to account for day/night and the curvature of the Earth. 


    Vacant land converted into farmland has significant (possibly greater) changes in abedo than urban areas and is a much greater part of the Earth's surface.  The melting of Arctic ice causes a greater change in albedo than the rural/urban change does.  We see that reflected in the Arctic increasing in temperature faster than the rest of the Earth.  If urban areas caused 30% of the warming they would all be extremely hot during the day.  This is not observed.  If your calculations were correct than albedo changes would account for all of global warming and that is not what is observed.


    If you look in the just released IPCC report you will undoubtedly find a chapter on albedo change.  See what the scientists say.  An old saying among grad students is "An hour in the library will save you a week in the lab".  See what you can find in the IPCC report and come back here to inform us.

  • It's Urban Heat Island effect

    blaisct at 01:01 AM on 14 August, 2021

    Thanks All for the input. You are increasing my understanding of the albedo effect. I appreciate the articles you mentioned and see that the subject is very complex and calculations like mine are only useful for understanding the simple significance of the many variables and not useful for reaching conclusions or predictions. One general conclusion that seem to come from all the articles and papers is that albedo is most likely significant but there is not agreement on how significant, or the range of each of the variables, or the total interaction of all the albedo variables. I sure hope that the GW experts are improving their models with new NASA satellite data. Does anyone out there know how much of the current GW data (1.1’C) in the IPCC model is accounted for by albedo change?
    For entertainment only, I redid the significance of the 0.7% urban of total earth surface what if calculation to include some of the comments.
    1. The reported albedo of urban areas is about 0.08 (double the 0.04). (Albedo on a 0.0 to 1.0 scale)
    2. The reported total albedo of the earth is about 0.31. (Assume that includes clouds and urban albedo)
    3. % of earth that is urban: =0.7%
    4. The non-urban area of the earth is: 100%-0.7%= 99.3%
    5. The contribution of urban areas to the total albedo is: 0.08 * 0.7% = 0.00056
    6. The total non-urban area albedo contribution to the total is: (0.31-0.00056)/ 0.993 = 0.31162
    7. Assume the non-urban area albedo in the 1880 era was the same as today: =0.31162
    8. Current earth population is about = 7.8 B
    9. 1880 era population is about =1.3 B (Using 1880 as the approximate start of IPCC temp data)
    10. Assume the 1880 era urban area was proportional to population: = 1.3/7.6*0.7% = 0.12%
    11. The 1880 era urban area contribution to total albedo was: 0.07*0.12% = 0.0000933
    12. The 1880 era non-urban area contribution to the total albedo was: (1- 0.12%)*0.31162 = 0.311257
    13. The 1880 era total albedo estimate is: 0.311257+ 0.0000933 = 0.311351
    14. The difference in 1880 vs 2021 albedo is : 0.311351 – 0.31 = 0.00135 (or about 0.14% albedo change)
    15. The reported output of the sun reaching the earth is about: 1367 W/m^2
    16. Assume that the urban albedo is only seeing one half (balk of urban areas are in the middle half of the earth’s surface) of the above due to the curvature of the earth: 50%
    17. Average surface of the earth cloud cover: =67%
    18. Average albedo of clouds: = 50%
    19. Total sun’s output reaching cloud covered urban areas + non cloud covered urban (corrected for curvature) is : 455 W/m^2.
    20. Therefore, this energy of the albedo difference is: 0.00135* 455= 0.61W/m^2
    21. I have seen conversion factors for converting this to ‘C in earth temperature rise of 0.5 to 0.7 ‘C/W/m^2. I’ll use the 0.5.
    22. The equivalent earth temperature rise of the above albedo change from 1880 to now is: 0.61*.5 = 0.31’C


    The IPCC reported temperature rise over the 1880 to now is about 1.1’C. This what if calculation implies that a 0.7% urban area could account about 30% of this temperature rise – not insignificant.
    One of the papers (in your previous references) on land use albedo change seems to agree that man-made albedo changes (mainly in agriculture by Mark Healey https://www.scirp.org/pdf/ijg_2020062914563820.pdf) are significant and could account for all the IPCC temperature rise. Mark Healey’s paper suggest that land use changes since 1910 are stronger than the UHI albedo effect.
    I am switching over to the “It’s albedo” thread. What are all the possible albedo changes since 1880?

  • It's Urban Heat Island effect

    MA Rodger at 06:51 AM on 28 July, 2021

    blaisct @62,


    Perhaps repeating some of the criticism @64:-


    You say "The IPCC seems to give man-made albedo changes low significance because it is hard to measure and hard to detect change." But difficulty does not appear to be something to dampen your enthusiasm.


    Do note that 0.04 albedo is far too low and, while potentially applicable to a sky-pointing piece of asphalt, is not applicable to urban areas. Also note that clouds float above cities forests and oceans alike and they contribute some 75% of the planet's albedo. And also note that the sun sets every evening and never rises to be overhead except at noon in the tropics. You need to divide the tropical noon-day value by four to satisfy the very simple geometry of spheres.


    radiation budget diagram


    The solar radiation actually reflected spacewards by the Earth's surface is shown in the diagram at 23Wm^-2. If by 2100AD, the planet's urban spread were somehow to reach over 0.7% of the planet's surface area (as the most extreme projection in the graphic @60 suggests is possible) and even if that 0.7% had an albedo of zero, that 23Wm^-2 would only reduce by [23 x 0.007 =] 0.16Wm^-2 which, despite the use of the most exaggerating numbers, is significantly smaller (x10 smaller) for 2100AD than the value you arrive at for today's value. Using more realistic numbers would return an insignificant result (x100 smaller).

  • It's Urban Heat Island effect

    Bob Loblaw at 06:45 AM on 28 July, 2021

    Blaisct @ 62.


    As Rob Honeycutt says, there is something clearly amiss in your calculations. Let me point out the obvious ones.


    1. You do not cite a sources for your urban albedo of 0.04. Wikipedia lists 0.04 as a value typical for fresh asphalt. Most urban areas are not fresh asphalt. I have a well-worn copy of Tim Oke's Boundary Layer Climates, where he lists typical urban surafaces as follows (p 281):



    • Asphalt 0.04 to 0.20

    • Concrete 0.10 to 0.35

    • Brick 0.20 to 0.40

    • Roofing materials (various) 0.08 to 0.35


    Your estimate of urban albedo is way too low.


    Typical natural land surfaces (Ok.e op cit, p 12)



    • Soils (wet to dry) 0.05 to 0.40

    • Deserts 0.20 to 0.45

    • Grass 0.16 to 0.26

    • Crop land 0.18 to 0.25

    • Forests 0.05 to 0.20


    You need to consider just what urban material is replacing what natural material. Then you can estimate a change in albedo. Most urban landscapes are not that different from natural ones.


    4. Global albedo is not just a surface albedo. You need to factor in cloud cover. For a global cloud cover of 50%, only half the surface is seen from space - and surface albedo changes only have half the effect you get when you ingore cloud cover. You'd need to know the cloud cover over the urban areas you are doing calculations for.


    Your estimate of the contribution of urban surface albedo is an over-estimate. A serious over-estimate.


    7 through 13. Urban area is not proportional to population. Haven't you ever noticed how much more closely packed people are in cities, compared to rural areas? Population density is not uniform. Oke (op cit, p291) notes that the urban heat island effect tends to be proportional to the log of population, not linear. You are seriously over-estimating the amount of global albedo change in relation to urban population growth.


    14 and 15. The 1367 W/m^2 figure is for a measurement perpendicular to the sun's rays, in full sun. To compare to CO2 and other forcings, you need to divide by four, as the CO2 forcing is calculated for the entire globe, perpendicular to the earth's surface - not the sunlit side perpendicular to the sun's rays.


    You are over-estimating the effect by a factor of 4.


    16. As you have the wrong forcing in W/m^2, you are getting the wrong temperature rise.


    17. Essentially, garbage in, garbage out.


    Real scientists have been doing this the right way for decades. Try this one from way back in 1979:


    https://science.sciencemag.org/content/206/4425/1363.abstract


     

  • It's Urban Heat Island effect

    blaisct at 03:59 AM on 28 July, 2021

    Thanks MA Rodger, my fault, I used the % (3%) of the earth land mass that was urban instead of the % of the total earth that was urban. The number from your graph of 0.7% urban (of the total earth area) seems to agree with other published information. I assume the heat from the “heat island” effect would be well mixed around the earth and become part of the total measurement of climate change. I present the following to check out the significance of the 0.7%.
    1. The reported albedo of urban areas is about 0.04. (Albedo on a 0.0 to 1.0 scale)
    2. The reported total albedo of the earth is about 0.31. (Assume that includes clouds and urban albedo)
    3. The non-urban area of the earth is: 100%-0.7%= 99.3%
    4. The contribution of urban areas to the total albedo is: 0.04 * 0.7% = 0.00028
    5. The total non-urban area albedo contribution to the total is: (0.31-0.00028)/ 0.993 = 0.31190
    6. Assume the non-urban area albedo in the 1880 era was the same as today: =0.31190
    7. Current earth population is about = 7.8 B
    8. 1880 era population is about =1.3 B (Using 1880 as the approximate start of IPCC temp data)
    9. Assume the 1880 era urban area was proportional to population: = 1.3/7.6*0.7% = 0.12%
    10. The 1880 era urban area contribution to total albedo was: 0.04*0.12% = 0.000047
    11. The 1880 era non-urban area contribution to the total albedo was: (1- 0.12%)*0.3119 = 0.31154
    12. The 1880 era total albedo estimate is: 0.311538+ 0.000047 = 0.311585
    13. The difference in 1880 vs 2021 albedo is : 0.311585 – 0.31 = 0.001585 (or about 0.16% albedo change)
    14. The reported out put of the sun reaching the earth is about: 1367 W/m^2
    15. Therefore, this albedo difference is: 0.001585* 1367 = 2.1680W/m^2
    16. I have seen conversion factors for converting this to ‘C in earth temperature rise of 0.5 to 0.7 ‘C/W/m^2. I’ll use the 0.5.
    17. The equivalent earth temperature rise of the above albedo change from 1880 to now is: 2.168*.5 = 1.08’C



    The IPCC reported temperature rise over the 1880 to now is about 1.0’C. This calculation implies that a 0.7% urban area could account for all of that temperature rise. I know this is over simplified, and was only done to find out the significance of small changes in a higher heat source ( over 4X lower albedo in urban areas vs the earth as a whole) on the earth surface. Other factors in albedo change should also be included: roads, forest fires land area, sea ice melting, land ice melting, rain forest destruction, and farming practices. I can only guess that including these albedo changes in the above would increase the man-made albedo global warming calculation.
    The IPCC seems to give man-made albedo changes low significance because it is hard to measure and hard to detect change. Population change and even atmospheric CO2 change should also be an indicator of historical man-made albedo change, just need a reference point.

  • It's Urban Heat Island effect

    blaisct at 02:23 AM on 22 July, 2021

    Should we be looking at the surface area of the earth these differences in trends represents? These graphs would better be related to climate change if they included some correction for urban area change. Over time this urban area may be increasing (and suburban area decreasing) thus the total heat into the atmosphere is also increasing proportional to that area change. I expect that including urban area increase due to population would show a significant increase in total heat going into the atmosphere over time vs the suburban areas. When urban areas of the earth were small (less than 1%) the “heat island” effect was probably insignificant. Now that the urban area is over 3% of the earth’s surface an area correction is needed. There may also be some differences in the albedo of cities due to construction practices and population density.

  • The Albedo Effect and Global Warming

    blaisct at 06:35 AM on 20 July, 2021

    Reading about resent NASA satellite data on finding increase heat loss to space makes me wonder how this increase in heat loss is consistent with the Radiative Forcing theory of the IPCC. My understanding of that theory is that as atmospheric CO2 increase it hold in more heat and makes the surface temperature hotter like a blanket effect while the heat loss to space remains the same. The NASA data does not seem to support the Radiative Forcing theory or I must not understand the Radiative Forcing theory. Where is the extra heat coming from?



    Also reading about the “heat island” effect from big cities (up to 15’F difference between urban and suburban) makes me wonder could this be related to the NASA data on heat loss? Has population gotten big enough to have an impact on global warming? The “heat island” effect is caused by the much lower albedo (reported as 0.04, cloud free) of urban areas vs the earth as a whole (reported at 0.31). Using IPCC data one can calculate that an albedo change of only 0.15% (+1’C) is needed to account for all of the temperature change from 1880 until now. (that is a hard to detect 0.001%/year). While we are waiting on that detection level we can use related data to estimate man-made albedo change like population or atmospheric CO2.
    The earth’s urban area is reported at 3.1% of the total area of the earth. The urban area back in 1880 (start of IPCC global warming data) is estimated at 0.7% (proportional to population) over 4X change. In 1880’s the “heat island” albedo effect was probably insignificant plus there was not many black parking lots or paved roads. The IPCC reports a 1’C rise in temperature since 1880. Using published information one can calculate the heat rise of the current 3.1% urban area at 4’C rise (since 1880) in earth temperate just from the urban area albedo change. (Using IPCC data of sun’s radiation to the earth at 1367w/m^2 and surface temperature rise correlation of 0.5 ‘C/w/m^2). The calculated 4’C rise is more heat than necessary to account for the 1’C observed this is probably due the reflective increase in clouds (water evaporation that eventually become clouds and reflects sun light) that would come with more heat from urban area. This overly simplified estimate of the man-made albedo effect suggests a more scientific version of albedo change should be included in any global warming model or theory. As the population of the earth gets bigger and urban areas grow this effect will get bigger. There are also other man-made albedo effects (destruction of rain forest, forest fires, melting of sea ice, and agricultural practices) which would be proportional to their % of the earth’s surface and their individual albedos.



    The earth’s population should be a good indicator of urban area increase and thus man-made albedo change. Atmospheric CO2 is also corelated to population should also be a good indicator of urban area increase (albedo decrease). Are CO2 and albedo confounded in their correlation to global warming? Which force is bigger? The above calculation suggest albedo. NASA's ongoing map of the earth's cloud free albedo should be a big help in including albedo in global warming models, initial results seem to support the above.


     

  • Models are unreliable

    Bob Loblaw at 00:54 AM on 7 July, 2021

    MAR:


    This all hinges on what is meant by "calibration", and whether or not the parameters in a model are arbitrary.


    Wiktionary defines "calibrate" as "To check or adjust by comparison with a standard." When discussing climate models, this implies that there is some adjustable parameter (or seven) or input that can be varied at will to create a desired output.


    There are many problems with this argument [that climate models are "calibrated" to create a result]:



    • What are we calibrating for? A global 3-d climate model has thousands (if not millions) of outputs. Global mean surface temperature is one simple statistical summary of model output, but the model has temperatures that vary spatially (in 3-d) and temporally. It also has precipitation, humidity, wind speed, pressure, cloud cover, surface evaporation rates, etc. There are seasonal patterns, and patterns over longer periods of time such as El Nino. All of these are inter-related, and they cannot be "calibrated" independently. Analyzing the output of a GCM is as complex as analyzing weather observations to determine climate.

    • How many input parameters are devoid of physical meaning and can be changed arbitrariiy? The more physcially-based the model is, the fewer arbitrary parameters there are. You can't simply decide that fresh snow will have an albedo of 0.4, or open water will evaporate at 30% of the potential evapotranspiration rate, just because it makes one output look better. So much of the input information is highly constrained by the need to use realistic values. All these have uncertainties, and part of the modelling process is to look at the effect of those uncertainties, but the value to use can be determined independently through measurement. It is not a case of choosing whatever you want.


    So, robnyc987's claim that you can achieve 100% accuracy by "calibrating" a small set of parameters is bunkum. If climate models are so easy to "calibrate", then why do they show variations depending on who's model it is? Or depending on what the initial conditions are? That variability amongst models and model runs indicates uncertainty in the parameters, physics, and independent measurements of input variables - not "calibration".


    Perhaps robnyc987 will return to provide more explanation of his claim, but I somehow doubt it.

  • 2021 SkS Weekly Climate Change & Global Warming News Roundup #17

    MA Rodger at 17:49 PM on 26 April, 2021

    Dale H @3,


    Further to #3, the declining CO2 levels over the last few ten-of-million years are usually put down to errision following the Himilayan mountain-building. The Antarctic ice appeared about 35Mya on the cooling planet. On a shorter time-scale, the shutting-off of the oceans between N & S America 3 Mya ago resulted in the appearance of the Arctic ice which has been fuelling ice ages ever since.


    The frequency of these ice ages swapped from 40,000yr to 100,000yr roughly 1 Mybp (so your 1.2Mya @1). A mechanism for this transition is not entirely nailed down quite yet (eg see Chalk et al 2017 or Willeit et al 2019). However the usual suspect is the level of dust from exposed land during glacial cycles and its reduction of the ice albedo. So when the lands of northern lattitudes have been scoured clean back to the bedrock, the dust is greatly reduced and thus the albedo of the less-dusty ice caps does not decline so much during high glaciation, allowing ice a longer period before destablising into an interglacial.

  • CO2 lags temperature

    MA Rodger at 08:39 AM on 13 February, 2021

    brneilsen @629,
    I'm curious as to the origin of your 'greenhouse gas response' equation T=3.2563ln(C)-3.0323. And if there were any merit in such an equation, I'd be interested to learn how it 'yields' a "0.95 degC" boost to global ice age temperatures resulting from a 190ppm to 280ppm rise in CO2. My abacus (which I would be the first to admit is not always reliable) 'yields' +1.26ºC using this bizarre equation.


    The usual calculation of CO2 forcing is ΔF = 5.35 x ln(CO2[1]/CO2[0]) which gives a forcing of +2.07Wm^-2 and a thus 'direct' impact on global temperature of+0.56ºC which would cause climate feedbacks that would perhaps triple this value to +1.7ºC.
    The global average temperature rise out of an ice age is usually reckoned at +5ºC to +6ºC so this calculated CO2 forcing would perhaps be responsible for a third of this temperature rise. And this result fits with assessments which find the contributions to deglaciation warming to be roughly 50% surface albedo, 37% GHGs (of which CO2 is the major player) and 13% atmospheric albedo.

  • Increasing CO2 has little to no effect

    MA Rodger at 21:27 PM on 12 February, 2021

    devcarr @427,
    I assume your surprise at the graphic @425Response showing the AGW temperature rise halting as soon as emissions stop because your questioning didn't expect the residual warming-yet-to-come to be pretty-much balanced by the reduction in climate forcing. Following the end of emissions, the GHGs are no longer being boosted by those emissions but instead falls as GHGs are naturally drawn out of the atmosphere.


    Perhaps your expected a response to your question @425 to be for the time for warming to end and equilibrium to be reached for a constant level of GHGs. This is of course a different question.


    The radiative imbalance is running at something like 1 Wm^-2 and if that were allowed to play out by keeping GHG levels constant, it would take a century or more before equilibrium is effectively achieved, with ECS=+3.0ºC suggesting an additional +0.8ºC. The time for this is uncertain as it is the longer-term processes that are poorly quantified when the ECS is assessed, and the value of ECS is famously poorly bounded.


    Hansen et al 2011 fig4


    The left-hand graphic here is Fig 4a from Hansen et al (2011) 'Earth’s energy imbalance and implications'. It shows a large part of the warming-to-come appearing in the first decade and that followed by a further large part in the following century. The big uncertainty is in the longer-term warming and this is the major cause of ECS being so poorly defined. And that long-term warming is not entirely a thermodynamic thing. Major longer term warming due in albedo can be caused by a minor and quite insignificant temperature imbalance acting over a long period. So any such long-term warming will result from the warming-already-achieved (+1.0ºC) as well as warming-to-come (+0.8ºC). And so if climate forcing were maintained, this longer term could then become quite significant.

  • There's no empirical evidence

    Philippe Chantreau at 07:12 AM on 25 January, 2021

    Gzzzm2013,


    The fact that you feel you can be sentencious and pontificate on such obvious elements as the atmosphere being transparent to solar light reveals that you have not done anywhere near enough reading to form an informed opinion that will hold any value. Everyone who contributes here is well aware of everything you just said. I could be pedant and add that temperature decreases with altitude up until you hit the tropopause, then things get a little more complicated.


    And incidentally, both albedo (which you hint at without naming it) and aerosols have been studied extensively. They are the subject of an entire body of scientific litterature, and are an examined item of denial at SkS: It's aerosols

  • It's waste heat

    MA Rodger at 22:27 PM on 17 January, 2021

    Climate Detective  from elsewhere, [link URL not being uploaded https://skepticalscience.com//news.php?n=4962#136555 ]


    Forgive me for demonstrating the major fallacies within your grand work but as you say "The calculations are not difficult to do."



    The assertion you make that "All energy generation by humans results in an output of heat or thermal energy" is fundamentally wrong. It is "power" that is generated and when this is through the application of kinetic energy from passing fluids, through the burning of recently grown plant matter or from intercepting solar energy that would otherwise be absorbed by the ground, there is not net increase of the planet's surface energy. It is only the absorbing of albedo-decreasing solar energy, the splitting of heavy atoms or the burning of fossil fuels to release chemical energy that does result increased the planet's surface energy.
    Further your attempts to suggest a significant level of climatic warming in an area such as the UK is due to these increases in surface energy ignores what would be the absence of such warming in adjacent areas where there is effectively no such surface warming, like the North Sea, the North Atlantic or for that matter, the whole of Africa. Taken over the whole globe, the UK is exceptional as it uses ~1% of global primary power but within ~0.05% of the global surface area. Because, as with all small areas of the globe, UK temperatures are very much dictated by the adjacent climate, the global average is the relevant value and that is trivially small. (Generally the energy released by FF use is exceeded by the GHG effect of the CO2 thus released in 9 to 18 months, depending on the type of FF employed.)

  • 2021 SkS Weekly Climate Change & Global Warming Digest #1

    MA Rodger at 01:37 AM on 13 January, 2021

    Dr. S. Jeevananda Reddy @16,


    ♥ Indeed, your book Reddy, S.J., (2008) 'Climate Change: Myths & Realities' is mostly available to read on a Google Books preview up to page 87 but pages 88-193 "are not shown in this preview".


    ♥ And nobody would mistake the critique within the 'blog' by William Connolley as your work.


    ♥ As for your assertion that my use of the adjective "erroneous" is not backed up by science, that is yet more "erroneous" input from you.
    I haven't read past your comment @6 but that yields conclusive findings for me.
    Your suggestions that solar or wind power are contributing to global warming is plain silly. A wind farm mixes air, and actually extracts energy locally to be transported for use elewhere. Temperature increases are simply the result of mixing of air, not the generating of warming.
    A solar farm will decrease albedo but the additional solar energy absorbed is comparable to the waste heat from a fossil-fuelled or nuclear powerplant. And this is without the CO2 from a fossil-fuelled powerpalnt which will add to AGW.


    Any positive climate forcing raises global temperature and this in turn will be amplified by feedbacks, particularly through the resulting higher specific humidity.
    Thus you write condescendingly @6: "increased CO2 raises temperature slightly and that produces an increase in water vapour, which does have the capability of raising atmospheric temperature" but with the added comment "However, it is not the case." So how is it that a climate forcing from increased CO2 (at 3.7wm^-2 per doubling) does not increase global temperature and thus initiate further warming from feedbacks? What scientific principle could you invoke to argue such a thing?

  • 2021 SkS Weekly Climate Change & Global Warming Digest #1

    Dr. S. Jeevananda Reddy at 17:47 PM on 11 January, 2021

    Negelj


    Global Warming: It is an estimate of the annual average part of temperature trend. The trend of 1880 to 2010 is 0.6oC per century in which global warming component is 0.3oC – 1951 to 2100 is 0.45oC – according to linear trend. But in reality it is not so as the energy component is constant over which superposed sunspot cycle. However, the reliability depends up on the data used. For example number of stations in around 1850 were < 100 and by around 1980 [started satellite data collection started around this time] they were more than 6000 and with the availability of satellite data the number of stations drastically come down to around 2500. The satellite data covered both urban-heat-island effect and rural-cold-island effect and showed practically no trend – US raw data series also showed this. However, this data was removed from internet [Reddy, 2008 – Climate Change: Myths & Realities, available on line] and replaced with new adjusted data series that matches with ground data series. Here cold-island effect is not covered. With all this, what I want say is warmings associated with solar power plants is added to global warming. How much?? This needs collection of data for all the solar power stations. Met station covers a small area only but acts like UHI effect – I saw a report “surface temperatures in downtown Sacramento at 11 a.m. June 30, 1998 – this presents high variation from area to area based on land use [met station refers to that point only]. So, solar wind power plants effect covers similar to heatwaves and coldwaves. Here general Circulation Pattern plays main role.


    Nuclear Power: Nuclear power production processes contribute to “global warming process” while hydropower production processes contribute to “global cooling process”; the nuclear power production processes don’t fit into “security, safety & economy” on the one hand and on the other “environment & social” concepts; unlike other power production processes, in nuclear power production process different stages of nuclear fuel cycles are counted as separate entities while assessing the cost of power per unit and only the power production component is accounted in the estimation of cost of power per unit; carbon dioxide is released in every component of nuclear fuel cycle except the actual fusion in the reactor. Fossil fuels are involved in the mining-transport-milling conversion-processing of ore-enrichment of the fuel, in the handling of the mill tailings-in the fuel can preparation-in the construction of plant and it decommissioning-demolition, in the handling of the spent waste-in its processing and vitrification and in digging the hole in rock for its deposition, etc. and in the manufacturing of necessary required equipment in all these stages and thus their transportation. In all these stages radiological and non-radiological pollution occurs – in the case of tail pond it runs in to hundreds of years. Around 60% of the power plant cost goes towards the equipment, most of which is to be imported. The spent fuel storage is a critical issue, yet no solution was found. Also the life of reactors is very short and the dismantling of such reactors is costly & risky, etc., etc.


    Michael Sweet/ Negelj


    In 70&80s I worked and published several articles relating to radiation [global solar and net and evaporation/evapotranspiration] – referred in my book of 1993 [based on articles published in international and national journals]. Coal fired power plants reduces ground level temperature by reducing incoming solar radiation. In the case of Solar Panels create urban heat island condition and thus increases the surrounding temperature. In both the cases these changes depends upon several local conditions including general circulation patterns. Ground condition plays major role on radiation at the surface that define the surface temperature [hill stations, inland stations & coastal stations] – albedo factor varies. Also varies with soil conditions – black soil, red soil. Sea Breeze/land breeze – relates to temperature gradient [soil quickly warm up and quickly release the heat and water slowly warm up and slowly release heat] and general circulation pattern existing in that area plays the major role in advection.


    Response to Moderator


    See some of my publications for information only:


    Reddy, S.J., (1993): Agroclimatic/Agrometeorological Techniques: As applicable to Dry-land Agriculture in Developing Countries, www.scribd.com/Google Books, 205p; Book Review appeared in Agricultural and Forest Meteorology, 67 (1994):325-327.
    Reddy, S.J., (2002): Dry-land Agriculture in India: An Agroclimatological and Agrometeorological Perspective, BS Publications, Hyderabad, 429.
    Reddy, S.J., (2008): Climate Change: Myths & Realities, www.scribd.com/Google Books, 176.
    Reddy, S.J., (2016): Climate Change and its Impacts: Ground Realities. BS Publications, Hyderabad, 276.
    Reddy, S.J., (2019a): Agroclimatic/Agrometeorological Techniques: As applicable to Dry-land Agriculture in Developing Countries [2nd Edition]. Brillion Publishing, New Delhi, 372p.


    2.1.2 Water vapour


    Earth’s temperature is primarily driven by energy cycle; and then by the hydrological cycle. Global solar radiation reaching the Earth’s surface and net radiation/radiation balance at the Earth’s surface is generally estimated as a function of hours of bright Sunshine. Total cloud cover [average of low, medium & high clouds] has a direct relation to hours of bright Sunshine (Reddy, 1974). Cube root of precipitation showed a direct relation to total solar radiation and net radiation (Reddy, 1987). In all these latitude plays major role (Reddy & Rao, 1973; Reddy, 1987). Evaporation presents a relation with net and global solar radiation (Reddy & Rao, 1973) wherein relative humidity plays an important role that reduces with increasing relative humidity. If ‘X’ is global solar radiation received under100% relative humidity then with the dryness [with relative humidity coming down] it may reach a maximum of 2X; and under net radiation also with increasing relative humidity net radiation is reduced. That means water vapour in the atmosphere is the principal component that controls the incoming and outgoing radiation and thus temperature at the Earth’s surface. Thar Desert presents high temperature with negligible water vapour in the atmosphere as maximum energy reaches the earth’s surface. However, these impacts differ under inland (dryness), hill (declining temperature with height – lapse rate) & coastal (wetness) locations and sun’s movement (latitude and declination of the Sun — seasons) (Reddy & Rao, 1973). IPCC integrated these under “climate system” and the advective condition by general circulation pattern [GCP].
    Cold-island effect [I coined this, see Reddy (2008)] is part of human induced climate change associated with changes in land use and land cover. Since 1960’s to meet the food needs of ever increasing population, started intensive agriculture – conversion of dryland to wetland; & creation of water resources; etc. In this process increased levels of evaporation and evapotranspiration contributed to raise in water vapour up to around 850 mb levels in the lower atmosphere. Unusual changes in water vapour beyond 850 mb level [for example at 700 mb level] become a cause for thunderstorm activity (Reddy & Rao, 1978). Wet bulb temperature (oC) at the surface of the Earth provides the square root of total water vapour (g/cm2) in the vertical column of the atmosphere; and also wet bulb temperature (oC) is a function of dry bulb temperature (oC), relative humidity (%) and square root of station level pressure (height) relative to standard value in mb [p/1060] (Reddy, 1976). Thus, unlike CO2, water vapour presents a short life with steadily increasing with land use and land cover changes. However, met network in this zones have been sparse and thus the cold island effect is not properly accounted under global average temperature computations. Though satellite data takes this in to account, this data series were withdrawn from the internet and introduced new adjusted data series that matches with adjusted ground data series. Annual state-wise temperature data series in India wherein intensive agriculture practices are existing, namely Punjab, Haryana & UP belt, showed decreasing trend in annual average temperature – cooling. Some of these are explained below:


    Reddy (1983) presented a daily soil water balance model that computes daily evapotranspiration, known as ICSWAB Model. The daily soil water balance equation is generally written as:


    ▲Mn = Rn – AEn – ROn - Dn


    In the above equation left to right represent the soil moisture change, rainfall or irrigation, actual evapotranspiration, surface runoff and deep drainage on a given day (n). The term Actual Evapotranspiration [AEn] is to be estimated as a function of f(E), f(S) & f(C), wherein they represent functions of evaporative demand on day n, soil & crop factors, respectively. As these three factors are mutually interactive, the multiplicative type of function is used.


    AEn = f(En) x f(S) x f(C)


    However, the crop factor does not act independently of the soil factor. Thus it is given as:


    AEn = f(En) x f(S,C) and f(S,C) = K x bn


    Where f(S,C) is the effective soil factor, K = soil water holding capacity [that varies with soil type] in mm and bn is the crop growth stage [that vary with crop & cropping pattern] factor that varies between 0.02 to 0.24 — fallow to full crop cover conditions (with leaf area index crossing 2.75). Evaporative demand is expressed by the terms evaporation and/or evapotranspiration. Evaporation (E) and evapotranspiration (PE) are related as:


    PE = 0.85 x E [with mesh cover] or = 0.75 x E [without mesh cover].


    However, the relationship holds good only under non-advective conditions [i.e., under wind speeds less than 2.5 m/sec]. Under advective conditions E is influenced more by advection compared to PE. In the case of PE, by definition, no soil evaporation takes place and thus PE relates to transpiration only – where the crop grows on conserved soil moisture with negligible soil evaporation. With the presence of soil evaporation, the potential evapotranspiration reaches as high as 1.2 x PE or E with mesh cover. McKenney & Rosenberg (1993) studied sensitivity of some potential evapotranspiration estimation methods to climate change. The widely used methods are Thornthwaite and Penman presented 750 mm and 1500 mm wherein Thornthwaite method is basically uses temperature and Penman uses several meteorological parameters (Reddy, 1995).
    In this process the temperature is controlled by solar energy but moisture under different soil types [water holding capacity] it is modified. This modified temperature cause actual evapotranspiration and thus water vapour. This is a vicious circle. For example average annual temperature in red soils Anantapur it is 27.6oC; in deep black soils Kadapa it is 29.25oC & in medium soils Kurnool it is 28.05oC. That means, local temperature is controlled by soils.
    Reddy (1976a&b) presented a method of estimating precipitable water in the entire column of the atmosphere at a given location using Wet Bulb Temperature. The equations are given as follows:


    Tw = T x [0.45 + 0.006 x h x (p/1060)1/2]


    W = c’ x Tw2


    Where T & Tw are dry and wet bulb temperatures in oC; h is the relative humidity in %; p is the annual normal station level pressure in mb [1060 normal pressure in mb, a constant] ; W is the precipitable water vapour in gm/cm2 and c’ is the regression coefficient.
    WMO (1966) presented methods to separate trend from natural rhythmic variations in rainfall and assessing the cycles if any. (Late) Dr. B. Parthasarathy from IITM/Pune used these techniques in Indian rainfall analysis. Reddy (2008) presented such analysis with global average annual temperature anomaly data series of 1880 to 2010 and found the natural cycle of 60-years varying between -0.3 to +0.3oC & trend of 0.6oC per century [Reddy, 2008]. This is based on adjusted data series but in USA raw data [Reddy, 2016] there is no trend. The hottest daily temperature data series of Sydney in Australia shows no trend [Reddy, 2019a]. Thus, the trend needs correction if the starting and ending point parts are in the same phase of the cycle – below and below or above and above the average parts. During 1880 to 2010 period two full 60-year cycles are covered and thus, no need to correct the trend as the trend passes through the mean points of the two cycles.


    3.2.4 What is global warming part of the trend?


    According to IPCC AR5, this trend of 0.6oC per century is not global warming but it consists of several factors:
    a. More than half is [human induced] greenhouse effect part:
    i. It consists of global warming component & aerosols component, etc. If we assume global warming component alone is 50% of the total trend, then it will be 0.3oC per Century under linear trend;
    ii. Global warming starting year is 1951 & thus the global warming from 1951 to 2100 [150 years] is 0.45oC under linear trend;
    iii. But in nature this can’t be linear as the energy is constant and thus CSF can’t be a constant but it should be decreasing non-linearly;
    iv. Under non-linear condition by 2100 the global warming will be far less than 0.45oC and thus the trend will be far less than half;
    b. Less than half the trend is ecological changes [land use and land cover change] part – mostly local & regional factors:
    i. This consists of urban-heat-island effect and rural-cold-island effect;
    1. Urban-heat-island effect – with the concentrated met network overestimates warming;
    2. Rural-cold-island effect – with the sparse met network underestimates cooling;


    2.2.1 Uncertainty on “Climate Sensitivity Factor”


    The word “climate Crisis” is primarily linked to global warming. To know whether there is really global warming, if so how much, climate sensitivity factor plays the main role. Climate sensitivity is a measure [oC/(W/m2)] – how much warming we expect (both near-term and long-term) for a given increase in CO2? According to Mark, D. Zilinka (2020), “Equilibrium climate sensitivity, the global surface temperature response to the CO2 doubling, has been persistently uncertain”.
    Recent modelling data suggests the climate is considerably more sensitive to carbon emissions than previously believed, and experts said the projections had the potential to be “incredibly alarming”, though they stressed further research would be needed to validate the new numbers. Johan Rockström, the director of the Potsdam Institute for Climate Impact Research, said. “Climate sensitivity is the holy grail of climate science. It is the prime indicator of climate risk.
    The role of clouds is one of the most uncertain areas in climate science because they are hard to measure and, depending on altitude, droplet temperature and other factors can play either a warming or a cooling role. For decades, this has been the focus of fierce academic disputes. Catherine Senior, head of understanding climate change at the Met Office Hadley Centre, said more studies and more data are needed to fully understand the role of clouds and aerosols. With this vital disputes how anyone can say there is global warming without solving this issue; so I said “global warming hysteria factor is climate crisis”.


     

  • Milankovitch Cycles

    scaddenp at 13:28 PM on 5 August, 2020

    Hmm I think Hansen & Sato calculated this and reported in AR4. More like 4% for global solar change, 21% for albedo change and remainder from GHG (CO2 + CH4). However, locally (65N) the milankovich forcing is very high, enough to determine whether snow melts out in summer or not and so trigger the large scale albedo changes.

  • Climate sensitivity is low

    Cedders at 01:29 AM on 24 July, 2020

    The big news announced yesterday is the narrowing of equilibrium climate sensitivity (ECS) from a combination of paleoclimate and historical measurements and feedback modelling, a study which will feed into IPCC AR6. As I understand it, ECS is now very likely (90% likely) to be within 2.0‐5.7 °C, and likely (66% probability) to be 2.6‐3.9 °C, with a longer tail above 4.5 °C than below 2 °C. Anyone 'gambling' on low sensitivity would lose. Sherwood et al, "An assessment of Earth's climate sensitivity using multiple lines of evidence", Reviews of Geophysics, 2020. http://dx.doi.org/10.1029/2019RG000678


    The following long review tells me more than I need to know about feedbacks of all kinds: Heinze et al, "Climate feedbacks in the Earth system and prospects for their evaluation", Earth System Dynamics, 2019. https://doi.org/10.3929/ethz-b-000354206
    Although there may be 'black swan' events and earth-system feedbacks, the idea that climate scientists aren't including albedo or cloud changes in models is incorrect.


    More recent info on feedbacks in the latest CMIP6 models is in Meehl et al, "Context for interpreting equilibrium climate sensitivity and transient climate response from the CMIP6 Earth system models", Science Advances, 2020. https://doi.org/10.1126/sciadv.aba1981 and Zelinka et al, "Causes of Higher Climate Sensitivity in CMIP6 Models", Geophysical Research Letters, 2020. https://doi.org/10.1029/2019GL085782, the latter including a nice figure S7 showing the contribution of different feedbacks in different models.

  • Models are unreliable

    Tom Dayton at 08:36 AM on 5 July, 2020

    Deplore_This: Also, you seem to be overweighting the practical importance of the exact value of sensitivity. If you're in a car 200 feet from a rock wall, heading directly toward that wall, it doesn't really matter much if your speed is 50 or 60 miles per hour; the consequences are bad enough in either case that you should be applying the brakes right now. For climate change there is the additional urgency that the problem gets worse as time goes on, so even if sensitivity is on the low end, that merely delays the same bad consequences by an inconsequentially few years. Yet another time urgency comes from the fact that the primary causes (in particular greenhouse gas emissions) and feedbacks (e.g., lower albedo from loss of ice) are impossible to reverse on time scales that will be useful. Ice loss, for example, effectively is permanent on human timescales. Another problem with delaying action is that warming accelerates due to feedbacks, sort of like interest accruing on a loan. The longer you wait to pay, the more money you need to pay.

  • 2020 SkS Weekly Climate Change & Global Warming News Roundup #25

    Eclectic at 20:06 PM on 22 June, 2020

    Lawrie @9 , Slarty Bartfast maintains that there is no global warming of any significance at a statistical level or at a physical planetary level.   So to him, albedo is irrelevant.


    Being more than 24 hours since his last posting, it seems unlikely that Slarty will return to attempt rebuttal of criticisms of against his many positions.  But we can hope he will return, to give a grand explication of his apparent errors and inconsistencies.


    In order to save the valuable time of SkS readers, I have looked further into Slarty's blog of May / June 2020 , and I have pulled out some points of interest.   Slarty's statistical/mathematical skills are (IMO) far exceeding his climate science knowledge  . . .  and somehow I am reminded of the very emeritus & climatically-challenged Ivar Giaever !


    I have taken some care not to misrepresent or quote-mine Slarty.   And please note that Slarty, in his blog, describes himself as: physicist / socialist / evironmentalist.


    1.   Sea level rise cannot be more than slight , because there is no CO2-AGW or CO2-led Greenhouse effect.  And so our coastal cities have zero danger of submersion.


    2.   What little CO2-greenhouse effect is present now, is produced by CO2 reflecting IR back to the planetary surface.


    3.   Weather stations fail to give valid planetary data because they are far too few, and (just as importantly) they are not evenly spaced.


    4.   "temperature records just aren't long enough ... to discern a definite trend ... you need at least 50 years."


    5.   "[land ice] In Antarctica (and Greenland) this is virtually all at altitude (above 1000 m) where the mean temperature is below -20 C, and the mean monthly temperature NEVER gets above zero, even in summer.  Consequently, the likelihood of any of this ice melting is negligible."


    6.   AGW forcing does not supply enough heat to melt ice at the poles [he seems to include the Arctic, too].


    7.   The Arctic is not warming.  [Presumably news to those alarmist Inuit who live there.]


    8.   Berkeley Earth Study repeats the sins of Hadley/ NOAA / etc but in a more transparent way ~ and BEST generates a falsely-positive warming trend through its misuse of Breakpoint Adjustments (rather than using raw data).


    9.   Slarty's oceanic thermal expansion calculations are wrong [as pointed out by MA Rodger].


    And there's more !

  • 2020 SkS Weekly Climate Change & Global Warming News Roundup #25

    Lawrie at 11:34 AM on 22 June, 2020

    Any process that absorbs visible light decreases albedo. Photosysnthesis, the process that produced fossil fuels, would seem to be way ahead of solar power. Following on from Slarty's logic then the quickest way to reduce global warming would be to clear fell all the earth's forests and replace them with reflective concrete

  • 2020 SkS Weekly Climate Change & Global Warming News Roundup #25

    CD at 08:42 AM on 21 June, 2020

    I noticed that one of the proposals of this article is more solar power. Yet solar power decreases the Earth's albedo and thereby increases local surface warming. This warming (even without CO2 greenhouse emisions) can be as high as 1 degC as I note here - climatescienceinvestigations.blogspot.com/2020/06/14-surface-heating.html


    In thermodynamics there is no such thing as a free lunch. All human activity warms the planet. So what is the plan? Go back to prehistoric living and get everyone to live in a cave?

  • How much would planting 1 trillion trees slow global warming?

    baeb at 03:16 AM on 9 June, 2020

    There are several characteristics of forests that aren't mentioned as far as I can see in the article or the posts.  (1) Mature forests sequester a large amount of carbon in soil micro-biology mainly through large amounts of mycorrhizal fungi and their creation of humates.  This will build over time and remain there.  (2) Tree leaves represent laminate surfaces containing water so their temperatures change slower than air around them, so they condense water as dew and in many places condense large amounts of water. (3) Roots and dead tree matter particularly on slopes reduces runoff and rapid evaporation so water helps cool forests (4) Forests change the amount of water in an area in many other ways.  Rainfall and snow doesn't evaporate as easily in shade as in fields or parking lots so it is released slower and tends to contibute to more vegetation growth. The difference is large in hot areas. (5) As I understand it, forests don't emit mid and far-range infrared as much as an adjacent area of earth, rock, pavement, etc. because they don't get hot and cool themselves through transpiration.  This increases water vapor in the air along with nucleating pollen, that contributes to rain down wind which encourages more biomass.  Water vapor becomes clouds which can create albedo themselves, rain for more plants, lower temperatures blocking sun, but of course they also operate as greenhouse gases so there are some questions there. But water that goes up also comes down.


    The work of Prof. Walter Jahne (online) is interesting on this and there were at least two Science magazine articles on the modeling 20 years ago of rain, vegetation, and climate alteration.  Which is to say that the effect of forests on global temperatures is, just like climate, a very complicated issue.  But I would like to know what anyone with expertise in both forest ecology and climate thinks about these issues (if there is such a person) and its relation to the important topic of the crisis we face and what to do about it.

  • We're heading into an ice age

    Lawrence Tenkman at 05:16 AM on 27 April, 2020


    MA Rodger,



    Thank you so much for your kind resopnse. I much appreciate you. Very interesting. So complex.



    It seems that the article by Willeit & Ganopolski (2018) suggest that much dust comes from the equatorial advancing edge of the glacier (erosion from the advancing ice edge as I understand?)… not necessarily plant death as Ellis & Palmer suggest. Also, albedo blunting for glaciation escape is not accomplished by dust alone… albedo is increasingly blunted by the increase of both snow age & of dust accumulation, combined together. Perhaps this explains the lack of a critical level for the dust as a single factor blunting albedo… as multiple factors that combine to do it.


    Those equations made my head hurt. I feel like a patient sitting in a doctor’s office asking questions and expecting them to make me understand concepts it took years of medical school to understand. For sure, that’s not possible, as I’d have to go through all the training you did… year by year ... more answers leading to more questions.


    But I do appreciate you very much. Thank you for taking the time.  Thank you for doing what you do.


    LT

  • We're heading into an ice age

    MA Rodger at 23:47 PM on 26 April, 2020

    Lawrence Tenkman @407,


    To clear up the "parting comment", it appears in a 2015 blog-post linked at the last paragraph of #405 above. The denialist flavour of this "parting comment" does explain some of the very odd comment in Ellis & Palmer (2016).


     


    The 'CO2 mechanism' I say is not explained is specific to the glacial maxima. Ellis & Palmer (2016) demonstrate temperature, dust and CO2 are correlated (in their figs 1, 4, 8 & 9). We could also include sea level/ice volume and methane into such correlations. So the question arises - What is driving what?
    During the drop into an ice age we can be reasonably confident that reduced northern insolation allows a build-up of northern ice sheets reducing regional albedo which has a global impact on temperature and kicks-off positive feedbacks in albedo, CO2 & methane.


    But the glacial maxima appear to have a particular pattern to them, perhaps clearest when sea level is considered. The Ice Ages step up a gear as they dive into the maxima.Ice Age Sea Level


    Ellis & Palmer point the finger at the CO2 feedbacks. They would have difficulty using albedo as the dust-levels are building at these points in the Ice Age cycle and Ellis & Palmer dismiss the idea of atmospheric dust-levels being a significant cooling factor.


    Given the constraints placed on the workings of Ice Age maxima by Ellis & Palmer, their hypothesis seems to rely on some strong CO2 feedback that comes into play at this point in the Ice Age cycle. So my question - Are the measurements of CO2 showing a big enough reduction?  What is causing these large reductions in CO2? And what causes these reductions to quickly reverse when the maxima is over?


     


    And not greatly removed from any discussion of 'CO2 mechanism'....


    Regarding the lack of 'threshold' for dust levels to bring Ice Ages out of their maxima, Ellis & Palmer Fig 4 (below) shows great variation in the peak level of dust as well as variation in the duration of high-dust prior to the glacial maxima. This I term a lack of 'threshold'. The general impression is that a generally high level of dust reducing albedo of global ice sheets awaits the increase in nothern insolation caused by the Milankovitch cycle.


    But surely this variability means the power of the dust-reduced albedo forcing is not strong enough of itself to be the trigger. It is possible that analysis would show the Milankovitch cycle and the dust-albedo in combination provides a consistent threshold level, or perhaps CO2 levels are also a factor in the mix. But such necessary analysis would require an approach somewhat less simplistic than Ellis & Palmer. (For instance, compare the Ellis & Palmer approach with that of, say, Willeit & Ganopolski (2018).)


    Ellis & Palmer fig 4


    I think that covers the issues from #407, hopefully in an understandable form.

  • We're heading into an ice age

    Lawrence Tenkman at 05:40 AM on 26 April, 2020

    Scaddenp & MA Rodger,


    Thank you so much for your responses.


    MA Rodger, thank you for reading that article an phelping me with it. Please clarify a few things for me if you don’t mind. You mentioned that "Ellis & Palmer fail to explain the mechanism driving the CO2 reduction and why this cooling doesn't keep on going… and that the peak-dust levels do not appear to have a threshold level." My impression from reading was they propose Earth gets cold enough at the nadir of orbital Milankovitch cycle to start forming ice, and if enough ice forms, albedo is sufficient resist subsqeuent Milakovitch warming cycles, and Earth plunges into into a glacial period via increasing of both ice formation & ice albedo feedback. Ellis & Palmer suggest CO2 falls because the cold makes the ocean draw CO2 in (increased solubility of the cold water) and this CO2 drop is what stops further cooling, b/c plant death from low CO2 & low temp causes the dust.


    It all sounded interesting to me… but even if their theory about dust were true about glaciation exit mechanisms, I don’t think it would be right to conclude that infinitely high man made CO2 & greenhouse doesn’t matter in today's world. This website has so much data suggesting we need to care.


    I’m not sure what you mean by: "the peak-dust levels do not appear to have a threshold level." What does that mean? Threshhold referring to a temp or CO2 level at which dust forms? Threshhold referring to a level of dust at which it is can melt ice? I thought the dust elevations seemed to occur during temperature & CO2 nadirsand seemed to precede warming consistently.


    Ellis & Palmer’s parting comment wasn’t in the website link I had (http://science.uwaterloo.ca/~mpalmer/stuff/ellis.pdf) (“So the only evil in this world is not in the atmosphere, it lies in the hearts of those who wish to starve plants and animals of their most essential food supply — CO2.”). But on YouTube, I did hear Ellis suggest we may be put here by “intelligent design” to burn fossil fuels to save us from an ice age. Sounded a bit off to me…. and made them seem quite biased. Hence, I wanted to hear from someone more educated that me on these concepts. Thank you so much for discussing this with me.

  • We're heading into an ice age

    Eclectic at 05:13 AM on 26 April, 2020

    MA Rodger , geoengineering climate by distributing iron (as fertilizer) to pelagic ocean, has been discussed in previous years.


    Tim Conway & Seth John (2014, Nature ) indicated that a large proportion of North Atlantic ocean-water iron was deriving from Saharan dust.


    There has been some more casual  discussion of the idea of dust from dry land similarly producing algal bloom and thus a reduction of atmospheric CO2.   This climate-cooling mechanism (which I have not seen quantified) would act in opposition to the dust-albedo mechanism suggested by Ellis & Palmer (2016) .

  • We're heading into an ice age

    MA Rodger at 23:24 PM on 25 April, 2020

    Lawrence Tenkman @402,


    I did manage a read-through of Ellis & Palmer (2016). I note it isn't published properly which is likely why it fails to get mentioned within the literature. (It is published here but only as an “unedited manuscript” which was to “undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form.” I see no “final form.”)


    There is within Ellis & Palmer mention of “another story for another day” with the suggestion that this would add to the grand theorising with explanations of Dansgaard-Oeschger events and the mid-Pleistocene transition. A paper co-authored by Ellis has appeared on the web explaining the pre-MPT 41ky Ice Age cycle as resulting from there being an extra southern-driven version of the Ice Age cycle which post-MPT ran out of land in the post-MPT permanently-iced-over Antarctica and leaving only the northern-driven post-MPT 100ky Ice Age cycle.


    I'm not sure how the pre-MPT cycles would fit in with the Ellis & Palmer theory of dusty interglacial-triggering. (The appearance of interglacials in beat with the orbital eccentricity wobble is described in this follow-on thesis as purely coincidental. The frequency is defined by the 70ky it takes to prime the system with ice.)


    The absence of proper follow-on work, of publication or of citations is a kiss of death to theories such as set out by Ellis & Palmer. But that does not explain what it says or why it is wrong to say it.


    Ellis & Palmer (2016) is a poor piece of work. It occasionally says some very silly things but I shall ignore those. It also gallops past the science rather than addressing it, indeed describing it as “scientific lacuna.” But I shall here ignore such hubris.


    The grand theory presented explains that the precession/obliquity within the Milankivitch cycles does not always lead to an interglacial and that this is not immediately explained by CO2/albedo alone. To cause an interglacial Ellis & Palmer invoke a dusty atmosphere which reduced ice albedo and, as warming takes hold, adds to this albedo reduction when warming brings greater levels of dust to the melting ice surface.


    They say the dust results from reduced CO2 which causes lower tree-lines globally and this increasing dust as plant-less dusty mountain tops grow into dusty mountains and then dusty hills with the lowered tree-line. A correlation of dust and CO2 is presented. This dust-correlation could be made with many other different factors so is effectively an exercise in curve fitting with the low-CO2>>high-dust relationship remaining speculative.


    What is also not explained in all this is the mechanism driving the CO2 reduction and why this cooling doesn't keep on going. The peak-dust levels do not appear to have a threshold level and if there is a CO2/ice-volume/Milancovitch/dust mechanism at work it has yet to be convincingly demonstrated.


    So without further work beyond those referenced here, work to fill in the gaps and thus enable this allegedly important theory to be properly published, it is fair to say that not a great deal has been done since the initial appearance of this work in 2015 which was then, with its parting comment “So the only evil in this world is not in the atmosphere, it lies in the hearts of those who wish to starve plants and animals of their most essential food supply — CO2. “, certainly more work concrened with denialsim than with scientific analysis.

  • We're heading into an ice age

    Lawrence Tenkman at 00:44 AM on 23 April, 2020


    MA Rodger & Scaddenp,
    Thank you so much for your quick responses.


    MA Rodger, very interesting. So dust-albedo blunting has always been a proposed mechanism for glaciation escape, but perhaps at MPT, the source for the dust “dried up” so it stayed cold longer? Ellis says MPT is beyond this paper’s scope, but he has a line suggesting that elevation of the Himalayas may have influenced MPT. Ellis suggests the earth beneath dying forests as a source for dust. His theory is: forests die from combination of low temp and low CO2 (both of which lower at higher elevations). I was just curious of what you thought of the correlation he found with dust in his graphs at the end. The paper’s first page or so lays out his premise. The charts and graphs are interesting, especially the one at the end where it shows temperature & CO2 drop, followed dust formation, followed by temperature rise. I thought it looked convincing. But I lacking the knowledge most of you have, am not qualified to critique it. If you have a moment, would you mind?


    Scaddenp, your response draws on knowledge that I don’t have (synchronous southern glaciation showing CO2 being driver), and thus I cannot follow. Forgive me. I'm not sure what you mean about the denial of phyiscs.  I know CO2 air concentration can affect temp (greenhouse) and temp can affect CO2 air concentration (water solubility). (Is that what you were referring to?). Ellis says that going into glaciation, temp drop caused CO2 drop. He says CO2 was 190 ppm, but it got low enough to affect trees at certain elevations (where partial pressure is low enough to reach a critical level of 150-160). He has a chart showing temp and CO2 concentration at various elevations in tropical and alpine regions. So far, I’m impressed with his data, but hesitant with his conclusions (in light of other overwhelming data)… but my level of knowledge makes my critique of limited value.


    My goal is to read this entire website… this happens to be just one nugget I’m trying to digest at the moment.

  • We're heading into an ice age

    MA Rodger at 05:03 AM on 22 April, 2020

    Lawrence Tenkman @399,


    While I'm not familiar with the paper you enquire about, Ellis & Palmer (2016), I note it not referenced by the likes of Willeit et al (2019) (which may be why I've not encountered it before).


    On the subject of dust-driven albedo forcing, the Ice Age cycle does present one puzzle addressed by Wileit et al and that is the mid-Pleistocene transition - when Ice Ages changed from a 41ky cycle to a 100ky cycle a million years ago. My (evident) weak understanding of the literature is that a potential candidate mechanism for the MPT rests with the repeated Ice Ages scouring the high-latitude landscape back to bare rock that then reduced the source of dust during the depths of an Ice Age and thus reduced the power of the negative dust-albedo feedback, this reduced power allowing Ige Ages to last 100ky rather than 41ky.

  • We're heading into an ice age

    Lawrence Tenkman at 03:11 AM on 22 April, 2020

    Ralph Ellis suggests that the warming that ends glaciation is not from CO2 greenhouse effect, but instead dust storms cancelling albedo on northern ice sheets. He proposes that the inertia of natural cycles is towards glaciation: cold orbit forcings eventually start ice sheet formation, which adds albedo, which adds cold & more ice sheets, etc. When it gets cold enough, oceans draw in CO2, and at a critical point (low enough temp & low enough CO2) rapid plant death ensures at certain elevations. This allows for erosion / dust storms, which land on ice sheets to cancel their albedo. Although the dust effect he speaks of would not have as widespread effect throughout the world, it would have a local strong effect on the ice to break the feedback process. Because the critical cold temperature may take several Milankovitch cycles to reach, his theory may explain why not all Milankovitch spike result in glaciation escape. I’m curious what experts think about his theory. (I am not an expert.) To me it seems to make sense and seems like a very disciplined paper. Maybe he uncovered the a key strong variable for escape of glaciation.


    In light of his dust-albedo cancellation being a strong effect, Ellis then concludes that CO2 is too weak to threaten overheating us or runaway greenhouse effect, and we shouldn’t worry about it… afterall CO2 of 280 ppm had too weak an effect (about 3.7 W/m2?) to prevent entry into glaciation. Ellis suggested that its almost like we were put here to burn fossil fuels to prevent an ice age.


    I hesitate to follow him to all of his conclusions though. For one, why the two must be mutually exclusive? If his strong local “trigger” indeed matters more for glaciation exit, why must CO2, which is cumulative, lasting, global, & rapidly rising not matter at a high enough level in our situation? I’m most concerned that temp is quickly rising despite cooling forces from solar & orbital cycles… and we’ve only begun to make CO2 at a very rapid rate.


    In terms of “preventing an ice age”. Many above suggest we’ve already prevented or much delayed it. Also, many above suggest, CO2 is like a gas pedal that recoils slowly once pressed. Future generations could always press the pedal further if determined necessary for ice age avoidance thousands of years in the future. But if we determine that we’ve pressed it too far, and are now in danger… too late. Can’t draw CO2 down rapidly.


    I’m no expert though… so I’d much appreciate an expert’s reflection on the significance of Ellis’s paper.


    http://science.uwaterloo.ca/~mpalmer/stuff/ellis.pdf

  • Milankovitch Cycles

    MA Rodger at 03:33 AM on 31 March, 2020

    mkrichew @32elsewhere,


    The inclination of our slightly-less-than-round Earth doesn't appear to impact the area subject to insolation by very much. The Earth's dimensions are given as a polar minimum radius of about 6,357 km and an equatorial maximum radius of about 6,378 km. If we were to consider the Earth as an elipsoid with these dimensions, its area facing-the-sun with a pole pointing at the sun would be just 0.3% greater than with the tropics-facing-the-sun but that would be assuming the axis is tilting through 90º relative to the sun and staying there throughout the year. Yet the actual change in tilt is nothing like 90º and is only fully acting at the solstices.


    The tilt varies between 22º & 24½º through its 40,000 year cycle, so just a 2½º variation, and that inclination is achieved relative to the sun only at the solstices, twice a year. So the increase in Earthly area facing the sun would vary by perhaps (0.3% x 3% x 70% =) 0.006% or a forcing of  very roughly  0.015Wm^-2. That's only about 4-months-worth of AGW so not exactly significant. And bear in mind the bigger winter/summer temperature range at the two poles resulting from any increase in tilt. That would firstly see more energy leaking away into space (as the energy loss to space is T^4 so a constant temperature is more energy-efficient than hot-summer:cold-winter) and secondly the albedo change from the greater area of winter snow will reduce solar warming. These two cooling effects should well-exceed the warming from the greater earthly area catching the sun from there being a greater axial tilt.


    (Note also the calculated effect of orbital eccentricity in the link @54 is 0.167%, some 30x greater. Even with this larger increase in insolation leads John Baez to the conclusion "if changes in eccentricity are important in glacial cycles, we have some explaining to do.")

  • The pros and cons of planting trees to address global warming

    John Wise at 00:31 AM on 25 March, 2020

    JoeZ: I didn't find it negative, but it is cautionary, and aimed at those who might think that all we need to do is plant trees, or who think that trees can be planted anywhere and thrive. The diminishing of the albedo of the far north by planting there was news to me(mind you, it is still so cold and dry there that few trees would grow).

  • The pros and cons of planting trees to address global warming

    RedBaron at 00:26 AM on 25 March, 2020

    As I have stated many times here at Skeptical Science, this is the wrong biome.


    Trees do have their ecosystem functions and obviously protecting and restoring forests is a good thing, but it is not the biome responcible for cooling the planet. Thus this is more like using AGW as an excuse to plant trees rather than an actual solution designed to reverse AGW.


    I am glad Dana Nuccitelli wrote about the flaws in using the wrong biome to reverse AGW, but I am surprised how resistant people are, even here.


    Allan Savory has come on this very site and tried to explain it. Probably by far the best expert scientist on the planet regarding grasslands restoration and how this in fact is the correct biome to accomplish the task.


    I myself have posted significant numbers of published science when and where I can find it. And I have been doing this for years here.


    We can even trace the original tree planting idea back to a "merchant of doubt" denial and obfuscation proposed by Freeman Dyson. He did have some minimal expertise, but not really in the climate science field long enough to be considered a reliable source.


    Yet this "tree planting" myth still persists over actual working scientists that have dedicated their entire lives to this one specialty? I am always confounded by this. Is it really so hard to understand that carbon on the surface is more likely to decay back into the atmosphere than stay sequestered long term as the carbon deep below the surface? Is it so hard to understand that C4 grasslands have much higher albedo, lower humidity from transpiration, and much higher efficiency of photosynthesis, while putting all these "ecosystem services" under the surface where they are protected?


    I have no problems with planting trees when and where we can, but really this is not helping much. 


    And please. Lets be honest here. The real reason the grasslands solution is being ignored or discounted is due to all the prime bits of land being already in intensive agricultural production. Oh and by the way the very reason they are "prime bits of land" is generally because of the very fact they were at one time either grassland or savanna and have already sequestered vast amounts of carbon before we plowed them up. In fact they already did what the pseudoscience claims is imposible. 


    I really seriously can't understand why of all places on the web, at least you guys can't get this very important part of climate science right. And please don't just delete of mod clip this post. Because if you'll just answer at least I can go try and find you some good citations to address them.

  • Increasing CO2 has little to no effect

    Eclectic at 21:24 PM on 9 March, 2020

    (Checking to see if my post uploads successfully to SkS)


    Thank you, MA Rodger.   Mr Dakota was quite off-target in trying to picture things in relative CO2 concentrations such as 0.041% or 410 parts per million.


    As you say, the presence of water vapor adds a large complication ~ except for Mars.   Adjustments also for albedo or reflectiveness at non-visual wavelengths . . . plus or minus reflectiveness of sulfate aerosols from industrial and/or volcanic origin.   Other adjustments for Earth's tilt or seasons, and for clouds at different heights & latitudes.


    The climate scientists certainly have their work cut out for them, to get a handle on it all.   Mr Dakota is probably tempted to think it's much easier just to be a science-denier, and firmly close one's eyes to reality !

  • It's CFCs

    EGS at 23:59 PM on 6 March, 2020

    Eclectic,


    Are you claiming that the degree of northern hemisphere ice albedo is a trivial amplification feedback in anthropogenic radiative forcing? 

  • Skeptical Science New Research for Week #9, 2020

    MA Rodger at 20:31 PM on 6 March, 2020

    swampfoxh @1,


    Your question doesn't 'ring any bells' with me and the authors you mention don't seem to lead anywhere that I can see.


    The 1,500 year timescale is occasionally mentioned as the time it takes the ocean waters to re-appear at the surface and so reach CO2-quilibrium with the atmosphere. That is part of what Goreau (1990) 'Balancing Atmospheric Carbon Dioxide' addresses but it is not the same as timescales for temperature equilibrium under otherwise-fixed CO2 levels.


    Rohling is the lead author of Rohling et al (2009) 'Antarctic temperature and global sea level closelycoupled over the past five glacial cycles' and this does consider multi-millennial equilibrium timescales but this concerns sea level. There is a connection in that the melt-out of, say, Greenland would both impact sea level and temperature as the albedo change constitutes a slow climate feedback (see this SkS post). But over such multi-millennial timescales with Milankovitch cycles in operation, it would require more than "modest" climate forcings to be significant.


    More directly addressing your question, the ice cores do show a small increase in CO2 levels over the last 8,000 years. This would provide roughly a 0.3Wm^-2 climate forcing which (slow and fast feedbacks so perhaps a sensitivity of 6ºC) could have given a total temperature rise of +0.5ºC. Yet spread over eight milennia, any residual effect today would be now miniscule.


    CO2 graph 10000 years

  • How much would planting 1 trillion trees slow global warming?

    RedBaron at 14:36 PM on 26 February, 2020

    @2

    US started planting trees in the 1920's and there are at least as many now as the pilgrim days or more.

    What is different is the prairies. Most of them have been plowed under, especially the tallgrass prairie.

    You can look on Google Maps all you want, but just because you see an area without trees doesn't mean there was a forest there before. In most cases it was prairie.

    Unplowed Tallgrass Prairie: Rarer Than Old-Growth Forest

    This is important because grasslands are the planets cooling system, not forests. 

    Cenozoic Expansion of Grasslands and Climatic Cooling

    You are seeing the reason why right now in Australia. Above ground biomass always returns to the atmosphere eventually either by decay or my fire.

    Whereas a large % of the carbon (~40%) fixed by grasslands is stored deep in the soil profile. And a high % of that carbon (~70%) enters the geological long cycle and does NOT enter back into the atmosphere for thousands or even millions of years.

    Then there is also the albedo effects, where trees absorb much more radiation and grasses reflect more due to averaging a much paler green coloration. 

    The US easily plants as many or more trees than they log and have been doing this for about 100 years. So already many trees planted have already grown up and been logged again, and replanted again.

    However, as I said before, this does not mean the US isn't contributing to AGW. They certainly are. But the primary ways are because of fossil fuel emissions and plowing up and destroying the biome responcible for cooling the planet...grasslands.

  • Climate's changed before

    scaddenp at 10:26 AM on 26 February, 2020

    Bruce. Hard to know where to begin.

    CO2 does not reflect sunlight - the gas is transparent to the frequencies of radiation coming from sun. However, the gas absorbs infrared radiation leaving the surface. So GHG lets energy in but slows energy going out.

    A warming ocean will emit CO2 (melting permafrost and temperate wetlands are other sources of GHG as temperature rise), but the oceans will not become net emitters of CO2 for hundreds of years. Currently they are absorbing CO2 (and becoming less alkaline).

    The situation at the end of an ice age is different - the changing distribution of sun energy (milankovitch cycles) result in summer melt in high northern latitudes reducing the albedo (and thus the amount of sunlight reflected directly back to space from ice). The warming releases GHG by the various mechamisms and as a result whole planet warms.

  • Climate's changed before

    KR at 02:50 AM on 25 February, 2020

    theSkeptik - " I would assume that both greenhous gases and temperature are correlated to other parameters"

    Well, yes, because physics. Long lived non-precipitating greenhouse gases in the atmosphere (CO2, CFCs, Methane) reduce IR emissions to space from the top of the atmosphere, which causes an imbalance of energy in the climate against incoming sunlight, and the climate therefore warms until radiated energy once again equals incoming.

    Along the way there are feedbacks both (mostly) positive and (some) negative which on the whole amplify the temperature response, such as changing CO2 solubility in the oceans, changing Earth albedo by melting snow over darker landscapes, methane releases from warming permafrost, and as a fast response changes in absolute humidity due to warm air holding more water vapor (itself a greenhouse gas, although as a feedback, not a driver).

    Physics comes first - correlation analysis to determine the exact amplitude of the response between drivers and the climate comes later.

  • Australia's wildfires: Is this the 'new normal'?

    Bob Loblaw at 11:50 AM on 20 February, 2020

    Mark: you say "...the more I see it needs to be a bigger part..."

    Note that the paper you found has a list of references. Note that the earliest of those references is from 1987.

    I can also point you to a paper from 1979:

    Anthropogenic Albedo Changes and the Earth's Climate

    Carl Sagan, Owen B. Toon, James B. Pollack

    Science 21 Dec 1979:
    Vol. 206, Issue 4425, pp. 1363-1368
    DOI: 10.1126/science.206.4425.1363

    https://science.sciencemag.org/content/206/4425/1363

    Studying changing surface effects on climate is not new. This is not something the climate science community is unaware of.

  • Australia's wildfires: Is this the 'new normal'?

    Eclectic at 11:32 AM on 19 February, 2020

    Mark Thomas , in my own simple understanding of things ~ deforestation has a global warming effect because woody carbon is released to raise the atmospheric CO2 level (and the replacement grasslands or cultivated fields are much lower in carbon mass . . . also, cultivated soil tends to lose some of its stored carbon, too).

    OTOH, grasslands & farmland have a higher albedo, and thus some cooling effect ~ but not enough to counterbalance the CO2 effect.  Then there are other complexities, such as the methane produced in rice-fields.

    It would be difficult to determine whether small-region climate changes (e.g. in the Australian continent) could be brought about by deforestation.  "Micro-climate" might well be cooled by evaporation from tall forests ~ but I am a touch sceptical about the evaporative difference between grassland/agri-fields and virgin land of the scrubby or semi-arid type (of which Australia has always possessed a vast amount).

    Soil moisture may not be very important ~ since on dry lands the greater temperature during the day is counterbalanced by the lower temperature at night.

  • Earth is heating at a rate equivalent to five atomic bombs per second

    MA Rodger at 21:44 PM on 16 February, 2020

    rip71749,
    Regarding the energy from burning fossil fuels, there is an SkS graphic illustrating the relative size of the various global energy inputs.

    I feel that 3.7Wm^-2 figure requires some further explaining. It is the value of Climate Forcing, the global energy imbalance, that would result from a doubling of CO2 which, without feedbacks, would result in a global temperature increase of +1ºC. These values are explained by the solar warming (less albedo) being globally 240Wm^-2 which thus gives an effective planetary temperature of (240/5.67e-8)^0.25 = 255K. Add 3.7Wm^-2 and it becomes 256K. These values, of course, apply high up in the atmosphere but the temperature increase from any forcing also applies to the surface temperatures as the lapse rate acts in a linear fashion down through the atmosphere.

    Additional to the initial forcing, there are feedbacks which increase the warming. They act as the global temperature rises, this temperature rise meaning the initial climate forcing is being equalised. Thus the feedbacks do not appear as an increased energy imbalance but instead extend the temperature effect of the climate forcing as it equalises with rising temperature.

    Now, at any particular time during AGW (where the Climate Forcing is applied slowly over a period and not all at once) the energy imbalance which is warming the globe (and so theoretically available to melt Greenland ice) will be far smaller than the accumulative Climate Forcing since pre-industrial times. Much of this Climate Forcing (and as negative forcings are poorly defined, the value of net Forcing since pre-industrial is imprecisely known but it is usually quoted as very roughly 2Wm^-2) will have been balanced by the global temperature increase since pre-industrial. It is solely the remaining energy imbalance that is available for melting ice caps, this running presently at something like 1Wm^-2.
    From the imbalance, there is then perhaps something like 16ZJ/year entering the climate which, if it could be brought to bear on Greenland's ice, would melt Greenland in something like 50 years. Of course, getting all that energy imbalance to Greenland would be impossible but if the ice were to set off across the oceans, it does become possible. Indeed, having melting icebergs bobbing about at lower latitudes would lower the global temperature and this will increase the global energy imbalance. (This is the mechanism behind the hypothesis set out in Hansen et al 2016.)

    Hope all that makes sense.

  • Milankovitch Cycles

    Map at 07:04 AM on 3 February, 2020

    Scaddenp thank you, that graph show exactly what I was looking for.  Interesting that it shows the opposite of what I was comprehending before with the albedo on land mass.

  • Milankovitch Cycles

    scaddenp at 06:25 AM on 3 February, 2020

    The change in albedo from human constructions etc. is is under "Land use" in the breakdown forcings.

    Source:

    This is discussed (with references to the source data) in Chapter 8, section 8.3.5.  If you havent already read the the IPCC report, then you should so before leaping in here.

  • Milankovitch Cycles

    Map at 03:52 AM on 3 February, 2020

    Ok a quick question.  I am seeing throughout the comments that people are correlating milankovitch's theory with albedo and ocean current to "explain" how solar insolation and ocean co2 can add to the temperature effects of the milankovitch theory.  The question that I have is;   Is there a way that the extra structures that man have put on the land mass in the northern hemisphere and the factor that we move so much snow to expose the ground to make travel easier possibly changing the albedo effect on solar insolation and combining with our increased co2 output to amplify our current global warming?

  • CO2 lags temperature

    Eclectic at 22:50 PM on 2 February, 2020

    In reply to commenter "Map" , from the other thread :-

    Map, we must be careful to avoid semantic problems/confusions, so it is best if we all communicate in the standard scientific language (i.e. meaning of terms).  You will mislead yourself if you use terms such as "minor ice ages"  every 21000 years and "major ice ages"  every 43000 years.  For that is not what the well-established Milankovitch theory indicates.  (See ice-albedo , CO2 feedback, etcetera.)

    You haven't said exactly, but you seemed to be referring to Greenland ice cores (such as GISP2 from central Greenland).  Their data comes from local conditions ~ not from global temperature changes.

    There have been interestingly large/rapid swings in temperature shown in GISP2 data, but these are are mostly around the unusual event of the Younger Dryas . . . and do not reflect a basic global climate change (nor the inflow/outflow of heat energy which is the underlying cause of climate change).

    For the sudden rise you mentioned, please permit me to quote climate expert Richard Alley :-  "[temperature increase was] for Greenland, and applies moderately well around the North Atlantic, primarily as a wintertime change because there was a rapid shift from wintertime sea ice to wintertime open water in important regions.    ... I can provide lots of chapters and verses on all of this, but the skinny version is that when the abrupt shifts happened, they primarily involved circulation rather than greenhouse gases, they didn't do a lot to global mean temperature, but they did do a lot to regional climates in many places, with large, rapid changes in North Atlantic temperatures, rapid shifts in monsoonal rains and in the edges of the tropical rain belts, smaller shifts in northern temperatures away from the North Atlantic, and lagged and opposite shifts in southern temperatures (so northern warming was followed by southern cooling)".

    Map, I hope that provides you somewhat of a help.  Please note that the big swings in the GISP2 proxy temperature data . . . are often displayed in the Deniosphere (of science-denying websites) ~ where it is implied that it's a world temperature chart.   Worse, the GISP2 graph ends at 1855 (yes, eighteen fifty five ~ quite before the modern AGW temperature rise began) . . . and the chart scale is so compressed, that the casual reader is misled into believing past temperatures were much higher than modern times.

    Denialist websites, such as WattsUpWithThat [WUWT] are well-known for these types of deceptions & falsehoods.   Map, if that's where you've been getting some of your information/misinformation . . . then you have been handicapping yourself.   WUWT contains all sorts of propaganda ~ and a lot of mutually contradictory crackpottery . . . and the comments sections there are half-filled with people who are still in complete denial of the basic physics of CO2 radiational properties.   Really a snake-pit of intellectual insanity !

  • It's magma

    Eclectic at 17:41 PM on 23 January, 2020

    Cpske ~ check out the Myth #196 of the Most Used Climate Myths (top left corner of page).

    The short story : climate is changed by alterations in the 240 watts/squ.meter absorbed by the planetary surface.  The 240 figure changes somewhat with solar changes ~ alterations in solar output, over the longer term or over the 11-year solar cycle) . . . or is changed by ice-albedo alterations . . .  or is changed by major volcanic eruptions throwing aerosols into the stratosphere . . . or is changed by man-made industrial pollution aerosols . . . or is changed by alteration in the levels of Greenhouse gasses (of course).

    OTOH, the flow of heat from the depths of the Earth is at an average rate of 0.09 watts/squ.meter ~ so very tiny that it is rightly  ignored in climate measurements & calculations.  This geothermal heat flow data is determined from temperature measurements take at a range of depths in deep boreholes.   There's no evidence of significant variation in this geothermal flow, nor any reason to believe it could alter the climate ~ even over thousands of years.   Yes, there are magma plume hotspots (such as formed the Hawaii islands) but they are fairly steady . . . and any new hotspots are too small in area to change the planetary average (the Earth's surface area being 510 million square kilometers).

    Cpske, if it's not too much trouble for you, I would be interested in having a look at the "static" you mentioned.   I regularly have a look at some of the Deniosphere blogs ~ such as WattsUpWithThat [WUWT], which does occasionally (well, rarely!) have articles of minor scientific interest.  But mostly the WUWT articles are rather childish propaganda . . . and the comments columns are 95% full of crackpot ideas & political ultra-extremism & more general intellectual insanity & recycled long-debunked climate "theories".  WUWT can be amusing, if you find amusement in Schadenfreude.   But I haven't noticed any "geothermal nonsense" there recently.   

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