Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.

Settings

Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup

Settings

All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Bluesky Facebook LinkedIn Mastodon MeWe

Twitter YouTube RSS Posts RSS Comments Email Subscribe


Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...



Username
Password
New? Register here
Forgot your password?

Latest Posts

Archives

Recent Comments

Prev  2213  2214  2215  2216  2217  2218  2219  2220  2221  2222  2223  2224  2225  2226  2227  2228  Next

Comments 111001 to 111050:

  1. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    #16 Your graph runs up to 1995. Pretty much all of the increase over normal values seen in the Pew Center graph comes after that year.
  2. Berényi Péter at 01:11 AM on 4 September 2010
    Hurricanes And Climate Change: Boy Is This Science Not Settled!
    "this graph, also from the Pew Centre, shows a 40% increase in North Atlantic tropical storms over the historic maximum of the mid-1950" "North Atlantic tropical storm" is a very bad concept if it comes to history. Before the satellite era many such storms must have gone unnoticed. Hurricanes making landfall in the US on the other hand are pretty well documented, if not for any other reason, because of insurance issues. There is no increase in severity whatsoever, a slight decrease, if anything. You can check it here.
  3. Berényi Péter at 00:44 AM on 4 September 2010
    Urban Heat Islands: serious problem or holiday destination for skeptics?
    #34 kdkd at 00:20 AM on 4 September, 2010 Yes, pretty good job description. It's just not my job. In fact I am surprised it is not done already, because it is the only reasonable way to quantify temporal UHI effect on surface temperatures. Comparing trends for "urban" and "rural" sites is worthless.
  4. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    I would suggest that the scale for the y-axis for the storm frequency plot seems like it was chosen to deliver a certain impression. How about a 0 to 16 scale to improve the appearance of objectivity? However in any case, this is a great summary. Some clearly unsettled science makes for a different tone to the discussion, which I enjoy.
  5. Quantifying the human contribution to global warming
    TOP writes: CO2 is about saturated so adding more has little effect compared to other GHG which are not saturated. Sorry, nope. This is a common misconception, however. See Is the CO2 effect saturated? on this site, or (for more detail) A saturated gassy argument (by Spencer Weart) ... or see the really excellent explanation of this issue over at Science of Doom: CO2 – An Insignificant Trace Gas? – Part Eight – Saturation
  6. Urban Heat Islands: serious problem or holiday destination for skeptics?
    BP #34 Actually your analysis is worthless until you report the statistical significance of your regression model. What's the value of its F statistic (does it predict better than change)? What's the value and statistical significance of the correlation coefficient (i.e. is the slope significantly different from zero)? Until you report these key parameters, it's not actually possible to determine whether your model is any use at all.
  7. Berényi Péter at 00:17 AM on 4 September 2010
    Climate change: Water vapor makes for a wet argument
    "when something else causes a temperature increase (such as extra CO2 from fossil fuels), more water evaporates. Then, since water vapor is a greenhouse gas, this additional water vapor causes the temperature to go up even further—a positive feedback" Not so fast. Water vapor distribution in the atmosphere is always uneven (it is not a so called well mixed gas). GHG effect also depends on its distribution (which is pretty fractal-like), not only on its quantity. If upon heating this distribution does not simply scale up, but gets a bit more uneven, WV "feedback" can easily get neutral or even negative. Any empirical data on higher moments of atmospheric humidity distribution? One thing is sure. The more uneven water vapor distribution gets, the higher the radiative entropy production of the Earth system becomes. In an open thermodynamic system with many degrees of freedom the maximum entropy production principle tends to hold. It is like self organized criticality (e.g. in sandpile dynamics). In even more simple terms as soon as some radiative flux gets "trapped" by GHSs, it punches a hole in the water vapor canopy where the excess radiation can freely escape to space. The exact mechanism by which it happens is not important, it should happen somehow due to pretty basic principles. Anyway, hot and humid air usually ascends, expands, cools down adiabatically, water condenses, latent heat released, precipitation falls down to surface, relatively hot dry air is released at cloud top, moves sideways, cools down radiatively to space, descends. It is a hole like the one I've mentioned above.
  8. Urban Heat Islands: serious problem or holiday destination for skeptics?
    Nice, BP. Of course, I have a lot of reservations and concerns about your analysis, starting with the question of how representative the data are. You've narrowed the GHCN list down to a fraction of the list, and the time period to a single decade. That's going to make your analysis quite noisy, I would expect. And in fact, the mean trend you find (3.2C/century) before you apply your population correction is quite a bit warmer than most of the land-only reconstructions for that same decade (1990-2000). The seven I looked at averaged 2.25C/century for the same period. So there are two possibilities -- either your station sample is unrepresentative, or your process does not provide a good estimate of the final impact of UHI on the gridded (or otherwise spatially weighted) land temperature reconstructions that other people are doing. If we assume that your subset of stations is representative, and the actual 1990-2000 land trend (after correction for UHI) really is 1.5C/century as you report, this would reduce the global (land/ocean) trend over the same period by about 12% ... from 1.87C/century to 1.65C/century. Given the various weaknesses in your analysis, I think this 12% is probably an overestimate for the effect of UHI on the global trend. I don't know whether it's as low as the 3% calculated above, but I would be very surprised if it's as high as 10%. Oh, yes ... I probably agree with BP's comment here: Perhaps satellite shots of night light distribution is a better proxy for UHI than population density trends averaged over administrative districts.
  9. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    Maybe an analogy to this might be a person found guilty of murder, sentanced to death, killed by the state only later to be found innocent. You're going to struggle to convinced everbody this is an example of justice working.
  10. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    There is another possible spin to this rather than this is the scientific method at work. It strikes me the real contention around this subject is the heat generated on the subject around 2005/2006. Maybe much less should have been made around the short number of years of rise, whether the data was flawed or not isn't really the issue. You also neglect to show that the past few years have been fairly ordinary storm seasons which I guess also makes it difficult to keep on screaming about the subject in the same way. It's really not good enough to say things are OK because we now have balance, the question should be what was the driving force of the frenzy in the first place.
  11. Quantifying the human contribution to global warming
    Looks nice until you put it in context including H2O.

    CO2 closes off the right hand side of the H2O absorption band and CH4 contributes to the left hand side. One thing that is clear from this graph is that climate sensitivity changes with absolute temperature.
    The total spectrum of all atmospheric gases is given in the bottom plot. This shows a "window" between 0.3 and 0.8 microns (the visible window), which allows solar radiation (without the lethal UV component) to reach the earth's surface. "Earth radiation", the upwelling infrared radiation emitted by the earth's surface, has a maximum near 10 microns. The total atmosphere plot shows that a narrow window (except for an oxygen spike) exists in the range of wavelengths near 10 microns.Iowa State
    The effect of CO2 on absorption of IR and re-radiation is not linear as the equations above suggest. Once a certain level is reached adding another molecule has much less effect. Think of window shades. Once they are shut, closing them more has little or no effect. Nor does a decrease in CO2 below 280ppm cause a negative forcing which the equation for dF suggests. The absorption bands (wavelength regions) for carbon dioxide are nearly saturated, but those for other gases are not, so one additional molecule makes a larger impact.
    Iowa State

    CO2 is about saturated so adding more has little effect compared to other GHG which are not saturated.

    Iowa State
  12. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    Thanks Graham "two recent peer-reviewed studies completely contradict each other" Is this Landsea and Holland? If not any chance of the references?
  13. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    Cynicus (no. 10). Good post. I'm going to use Rotterdam as one of my "poster children of sea level rise." You seem to know a lot about the Netherlands: I'm guessing that you are Dutch. In any case, if you do know a lot about Rotterdam and sea level rise, I'd like to hear from you off-list. Email me, if you want, at huntjanin@aol.com
  14. How we know an ice age isn't just around the corner
    You know, I don't think there's enough information in the graph above. Here's an improved version, with some additional content -- I've added in total solar irradiance (TSI). Clearly, over the last 30 years, CO2 and temperature keep rising (green and red or dark-red lines), while PDO (blue) is fluctuating and solar irradiance (yellow) is stable or declining. It should be noted that this kind of visual correlation is not actually how scientists attribute climate change. This graph doesn't prove that CO2 causes the observed warming. But the graph is certainly consistent with the claim that CO2 causes the observed warming, and that solar and PDO are not the cause. So ... anything else we should add into this figure? There's still a little white space left in there.... :-) Apologies for straying off-topic. -------------- More fine print: See above for sources of PDO, temperature, and CO2 data. Solar irradiance data from University of Colorado, shown annually and with a 22-year LOESS smoothing function.
  15. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    tobyjoyce, a bit offtopic, but your polder-to-polder pumping strategy you described is not correct. Polders are usually surrounded by two ring levees with a canal in between the levees which is called the 'boezem'. Excess water from the polder is pumped into the boezem canal. The boezem canals are interconnected by even more canals, eventually leading to the sea or the IJsselmeer lake where the surplus water is pumped (or under free-fall via a 'spui' which is a type of sluice that can provide an open passage) into the Northsea. The water level in the boezems is approximately equal to the old lands and thus higher then levels in the polders (which used to be lakes), up to several meters. In times of drought or stale-water conditions in the polder fresh water can also be let in from the boezem into the polder, effectively reversing the flow of water. On the subject of AGW and sea level rise: Pumping is a lot more costly (in terms of construction, maintenance and energy use) then free-fall dumping of excess water into the sea. So as sea levels rise and the lands in the western Netherlands are slowly sinking due to isostatic rebound from the last ice age as well as compaction of peat soils due to deep level water extraction, the time excess water can be cheaply dumped in free-fall during low tides will shorten. Unfortunately rainfall is also expected to intensify, causing greater peak demands for water removal. These factors combined will require more pumping installations and more energy usage for keeping the lands (and polders) dry. Which, ofcourse, will cost society some serious money.
  16. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    Huntjanin @ 6 - indeed, storm surges have been the principal cause of salt intrusion into soils of the Pacific Islands for some years now. 2005 was a particularly bad year for powerful cyclones in the region. The Cook Islands were hammered by 5 cyclones in just over a month!. Check out some of the photographs here: Five Weeks of Fury I don't know if you're familiar with Niue, but my wife and I holidayed there back in the late 1990's. It's basically a giant rock thrust up out of the ocean. The Niue Hotel, where we stayed sits atop a cliff face perhaps 30 meters high. I fished off it a few times, it's quite a drop, the few fish I did catch fell back into the ocean. Anyway, cyclone Heta hit the island in 2004 & the accompanying storm surge completely obliterated the hotel room we stayed in. I couldn't believe it when I first saw the press coverage, 40 + meter waves!. If you have a look at these photos here, near the bottom of the page you can see the hotel manager standing outside, and the sea in the background gives some idea of how high above sea level it actually is. In fact most of the dwellings pictured are well above sea level - along the same cliff face. Must have very frightening when the highest point on the island is only about 60 meters above sea level.
  17. How we know an ice age isn't just around the corner
    Not trying to pile on here, but here's a helpful comparison for GallopingCamel: Note that the blue line (Pacific Decadal Oscillation, or PDO) doesn't match the red and orange lines (temperatures, from surface [GISS] and satellite [RSS]) very well ... especially during the last three decades. In contrast, the green lines (log of CO2, from ice core [Law Dome] and direct measurement [Mauna Loa]) match the temperature record more closely. Adding in the effects of other greenhouse gases, and subtracting the effects of volcanic and anthropogenic aerosols, would make this match even closer. Bottom line, ocean oscillations can't explain the observed temperature trend. Greenhouse gases can. -------------- The fine print: PDO data from University of Washington. Surface temperatures from GISS land+ocean. Satellite temperatures from RSS. Law Dome CO2 from NOAA NCDC. Mauna Loa CO2 from NOAA ESRL. PDO and temperature data shown in monthly and 120-month LOESS smoothed versions. Law Dome CO2 dating based on "air age" with 20-year smoothing. Mauna Loa CO2 (monthly) are seasonally adjusted. Both CO2 data sets were log-transformed (base 2). Data sets with differing units (PDO, temperature, log[CO2]) have been scaled to fit on the same graph.
  18. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    Daved, The paper can be viewed here. Their models do not consider CO2 but instead consider SSTs and atmospheric and ocean circulation patterns. Those models do a good job of representing modern TC actvitity so there is reasonable confidence in their Pliocence "forecast".
  19. Berényi Péter at 22:31 PM on 3 September 2010
    Urban Heat Islands: serious problem or holiday destination for skeptics?
    I have selected 270 GHCN stations worldwide with a reasonably uniform distribution over land in such a way, that all of them had almost complete coverage of the years between 1990 and 2000. Then I have computed base 2 log population density difference of that decade for each station along with temperature trend at that location. The stations are divided into three classes according to population density around them in 1990: dense: more than 15/km2 medium: between 0.8/km2 and 15/km2 sparse: below 0.8/km2 (but at least 0.01/km2) As you can see the scatter plot is not very different for these categories. Therefore, if there is a dependence of UHI on local population density, it extends well below 1/km2 indeed with no breakdown of the relation in sight. But the most important finding is that there is a (not very strong) correlation between these two parameters, so a regression line can be computed. Average temperature trend for these stations was about 0.32°C/decade between 1990 and 2000. But part of this increase is due to the 0.2 increase in base 2 logarithmic population density during this timespan, so we have to consider the regression line at zero. It is about 0.15°C/decade there. So more than 50% of the trend is due to increase in local population density around GHCN stations (most of the rest is probably NH soot pollution over snow and ice). This effect is also known as UHI (Urban Heat Island), although as we have seen it has not much to do with urbanization as such, it's just the local effect of increasing population density, even in very sparsely populated areas. I think this is the proper way to look for an UHI effect in land surface temperature records. That is, one should analyze the connection between changes in local population density around measurement points and surface temperature trend at the same location. I am afraid it is not done (yet) by those, who are responsible for maintaining these datasets, although by now many thousand billion dollar political and business decisions are dependent on their correctness (or its lack thereof). Also, I can see the problems with the GPWv3 dataset. Perhaps satellite shots of night light distribution is a better proxy for UHI than population density trends averaged over administrative districts.
  20. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    Miekol, #2, More like "more than 500 years" for dyke building in Holland, rather than 100. Jared Diamond has a good section on Holland in his book Collapse, which I am re-reading. The dykes go hand-in-hand with a co-operative ethic. Each "polder" (dyked area) pumps water into the neighbouring polder until it reaches the sea. Each polder depends on the one nearer the sea. Ironically, the Dutch had the world's first capitalist economy and stock-exchange. Also, the world's first speculative bubble (in tulip bulbs). We may have a lot to learn from the Sutch experience!
  21. Climate change: Water vapor makes for a wet argument
    davidwwalters, no CO2 doesn't 'hold onto' heat energy at all. Think of each CO2 molecule as a tiny spinning mirror which is transparent to visible light, but reflective to infrared. A photon of sunlight hits the CO2 molecule and goes right through... down to the surface where it heats up a rock or something. The rock then emits a photon of infrared radiation upwards towards space. With no greenhouse gases in the atmosphere that heat would just go up and escape. WITH CO2 and other GHGs it goes up, hits a CO2 molecule, and bounces off in a random direction. Maybe it continues going upwards (to escape or bounce off another GHG molecule) or maybe it goes back down and 're-heats' the surface. The greenhouse effect does not work by 'trapping heat' within molecules of greenhouse gases. It works by slowing down the rate at which heat escapes the atmosphere into space. That heat winds up in molecules of other gases, liquids, and solids rather than just traveling up and out to space.
  22. The surprising result when you compare bad weather stations to good stations
    @Dappledwater: just replace "blood pressure" with "EKG". Definitely, if the cardiac graphs recorded by people of dubious competence were very similar to the ones recorded by the experts, it would be a surprising result that would suggest further investigation is needed before declaring the patient as "healthy" or "sick". For EKGs we do have guidelines, it's not too difficult to record them incorrectly if you don't know what you're doing, equipment may be out of date, it gets replaced, etc etc. Just like with USHCN stations. This should help understand the relevance of the analogy. @michael sweet: for the n-th time, we are not talking about "warming trends" in general. We are talking about the warming trends that appear for both well-sited and poorly-sited USHCN stations. This is the topic of the blog but for some reason people keep trying to talk about something else (in your case, the content of the AR4 SPM of all things). Please try to stay on-topic.
  23. Climate change: Water vapor makes for a wet argument
    -I'm no scientist, but I want one who is to explain how the phase change of water affects water vapor's role as a green house gas relative to CO2. My understanding is that when water vapor condenses as water droplets in clouds, it releases its latent heat energy at that point. So, water constantly is gaining and loosing heat energy, and CO2 just holds on to the heat energy?
  24. How we know an ice age isn't just around the corner
    GC #27, using the UAH temperature data we can calculate five year average global anomalies; 1990-1994: -0.04 1995-1999: 0.14 2000-2004: 0.18 2005-2009: 0.23 All other data sets show GREATER warming. So no, this is not a matter of 'which data you look at'. ALL data sets show warming and your claim of cooling the past ten years (the hottest decade on record in all data sets) is simply false. The years 2007-9 were relatively cool... but then 2010 thus far is at +0.55 C anomaly in the UAH data... which is higher than the 0.52 C record they have for 1998.
  25. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    Would someone like to write Basic post on storm surges? I think they are likely to cause a good deal of damage to lowlying places in the years ahead.
  26. Sea level rise: the broader picture
    HumanityRules at 14:18 PM on 3 September, 2010 If ENSO is affecting MSL variations about the longer term trend then we need records longer than a couple of maximum ENSO "cycles" to begin to be able to determine any underlying acceleration trend that is not biased by this variability (to do with Nyquist criterion, sample rate theory, - hope this makes sense). Looking over the longer term, I was trying to create a chart showing annual trend of 17 year gradients throughout the tidal/altimeter record, which I hoped would answer (or allow more informed discussion on!) your point as well as the valid ones Ken made earlier on the 1930s/1940s rise rate. However I realized Church 2008 has already done something similar with 20 year trends: Whether we tack on the 3.3mm 17 year altimeter trend to this or not, we see that there is an accelerating trend throughout the overall record, relatively high acceleration in the early 20th century, and more recent acceleration in the late 20th century. These trends and possible causal factors are discussed in more detail in Woodworth 2009.
  27. How we know an ice age isn't just around the corner
    GC @ 29 - as Phil Scadden has pointed out, the PDO 30 yr cycle thing seems to be based on imagination, not the data:
  28. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    Hi ProfMandia , If scientists cant agree on the effects of raised CO2 and Temps on TC in our own time how can we be sure that the Federov, Brierley, & Emanuel models truly represent an era 2.5 to 5 million years ago ? . Even if their half right its still scary but the big wave surfers will be happy .
  29. How we know an ice age isn't just around the corner
    GC writes: Which data is wrong? The satellites or the ground stations? I don't pretend to know the answer but until someone can come up with a convincing explanation for the discrepancies, we should all try to keep our minds open. What discrepancies? The RSS satellite record and all the major land+ocean temperature records currently agree to within 0.01C/decade. UAH is just slightly lower. When there were discrepancies in the past, they turned out to be due to errors in the processing of the satellite data, not due to errors in the surface data. For example, there was the famous case where UAH was accidentally applying the satellite-drift correction factor backwards. Also, FYI, contrary to your claim, none of the temperature records shows "temperatures have drifted lower over the last decade." Land surface, sea surface, and lower troposphere temperatures have all increased since 2000. Since these are measured using completely different -- and independent -- technologies, the agreement among them is quite convincing.
  30. The surprising result when you compare bad weather stations to good stations
    Chriscasnaris @ 58 - how many dodgy sphygmomanometers have you run across in the course of your practice?. Using analogies can be useful , but not irrelevant ones - the temperature record deals with temperature anomalies not absolute temperatures, and I've yet to see anyone claim that the US temp stations have all recorded the same temperature, on any given day. And if you find the Menne paper puzzling, this must cause you total befuddlement: from 70 USHCN stations
  31. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    During the Pliocene, about 2.5 to 5 million years ago, CO2 levels were comparable to today's levels (near 400 ppm) and the climate was about 3 oC to 5 oC warmer than pre-IR. Geographically, the Earth was also very similar to today so the Pliocene offers a glimpse of what the world may look like by the year 2100. Federov, Brierley, & Emanuel (2010) modeled the expected TC activity in the early Pliocene world. This figure is a comparison of modern TC activity (a) and that of the Pliocene (b). This image is a sobering look at what may lie ahead in our world by 2100.
  32. Climate change: Water vapor makes for a wet argument
    @Johnd You are not answering the fundamental question. The earth has been a system more or less in equilibrium for thousands of years . For thousands of years the amount of water evaporating has been roughly the same a the amount of water vapor condensing. The mechanisms of evaporation you describe have existed as long as the earth exists. The question is: What has caused the earth’s climate to deviate from this situation ? You cannot say “an increase in water vapor concentration in the atmosphere”, because then you have to explain why this concentration has increased in the first place. You cannot pull yourself up by your own hairs. The consequence can not be its own cause. The generally accepted answer to the question is: CO2. We have put an enormous amount of CO2 in the atmosphere, causing the levels of CO2 to increase by 35% compared to pre-industrial times. This caused a temperature rise, the temperature rise caused more water to evaporate, and more water vapour in the atmosphere in turn leads to even higher temperatures. If you have an alternative theory, I’d like to hear it.
  33. How we know an ice age isn't just around the corner
    GC writes: Global temperatures have drifted lower over the last decade and are likely to fall for at least another 10 years. No they have not. Here is the RSS satellite record: The pink line shows the trend through 2000. Note that from 2001 onward, most months have been above the pre-2001 trend line, with the notable exception of the 2008 La Nina.
  34. Climate change: Water vapor makes for a wet argument
    With regard to the JohnD/scaddenp conversation; be careful not to confuse rate with equilibrium. The speed at which any process occurs bears no relationship to how far it can go, and changes to the rate will not affect the "equilibrium" value. This sounds somewhat counter-intuitive, but that is a consequence of the fact that, in the real world, we rarely get a view of a complete system at equilibrium. Factors affecting the rate of water evaporation such as "global dimming", atmospheric "churn" (wind) and local heating of wet surfaces will not affect the total amount of water vapour the atmosphere can hold, but will affect (locally at least) the rate at which water evaporates. A high rate of evaporation is what is required for drying clothes.
  35. The surprising result when you compare bad weather stations to good stations
    Such close correspondence between two set of data has a somewhat surreal quality. To take the blood pressure example, you visit 100 doctors some of whom have good sphygmomanometers and some have dodgy ones. Let's say you visit the same doctors a year later - if your blood pressure has gone up, you'd obviously expect an upward trend in the overall picture. However, if every sphygmomanometer showed an almost identical rise in blood pressure of, say, 20 mm-Hg +/- 0.5 mm-Hg, you'd be wondering about the validity of the data set. The closeness of the correspondence at least as presented here seems out of keeping with the messy quality you find in real data which tends to meander and scatter. None of this disproves a rising temperature trend. However, there's something puzzling about the data.
  36. Arkadiusz Semczyszak at 18:49 PM on 3 September 2010
    Quantifying the human contribution to global warming
    ... from the point 3 of my comment, follows that the natural balance of flux - sink of CO2 - in the preindustrial era - natural balance can not be - not exist - unless the scale of n x thousand years.
  37. Quantifying the human contribution to global warming
    Dana, If by the range you mean 2-4.5°C then my understanding is that this range comes from the water vapour feedback. There seems good concensus that there would be around 1.5oC climate sensitivity directly from the properties of the CO2 molecule. The range comes from the extent to which water vapour plays a part. My question was really around whether water vapour has a linear response to the increase in CO2. I can accept that oscillations don't create heat but in terms of how we measure warming then I think an oscillation can 'retain heat' at least in terms of the measurements we make. If you catch an oscillation on the rise, and fail to measure the whole system (primarily the ocean) then it can lead to a trend in the measurements. Give it another 100 years (or a few decades of good ARGO data) and we'll probably have enough data to draw a line under this but neither you or me are happy with that answer. So I'm just looking for direction that the oscillations are recognised, measured and put to bed. One of the papers is this. You can infer from the results that ~2/3 of the recent warming is from the upstroke in a natural oscillation. The 50% estimate was in a private email from a climate scientist who says the work is due for publication. I'd be happy to send that mail to John Cook for him to confirm it, without naming the scientist, but I think that's probably pointless given we wouldn't be able to discuss the mechanisms involved. My point would be there are climate scientist out there who are looking at oscillations in the climate and think it is contributing to recent trends at least on the regional level. When the Basic version of polar amplification appears we can probably discuss this further.
  38. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    Tell that to the Nigerians.
  39. Arkadiusz Semczyszak at 18:29 PM on 3 September 2010
    Quantifying the human contribution to global warming
    In that case, I also make a very short balance ... Of course, this has already been spoken, not once but worth it (to organize discussion) in a condensed recalled again (absolutely essential) and most real skeptical arguments: - Assessment - assessing the feedback resulting from the increase of CO2 made by different researchers are up to several hundred percent different from the above presented - They often get even a negative balance of feedback. Moreover, also the IPCC in its report (full version) draws attention to the considerable range for uncertainty in their estimation. - changes in the value of some RF far exceeds the size of RF CO2 during the analyzed period. For example, I recall: here: “... the total global cloud cover reached a maximum of about 69 percent in 1987 and a minimum of about 64 percent in 2000s ... ... a decrease of about 5 percent. This decrease roughly corresponds to a radiative net change of about 0.9 W/m2 ...” and albedo change - by (generally recognized in the scientific world), more recent reconstructions from ice cores with higher resolution (not to mention other than the "core" reconstructions) during the last millennium, the level of CO2 in the atmosphere has changed much more than that in Figure 1 (Max. 60 ppmv between circa 1150 to 1300 yr A.D.), often reaching 320 ppmv (remember this is based on ice cores), ... and as says F. Engelbeen: “A causes B and shows a good correlation. A causes C and shows a good corelation. Thus B causes C, because there is a good correlation between the two. But that correlation is completely spurious, as there is not the slightest physical connection between B and C.” (...) - The effect of the sun at the Earth's climate is not only the TSI, and the Sun is out in the absolute most of their superposition cycles and cycles associated with Sun.
  40. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    Easy, build dykes. The Dutch have been doing it for over 100 years.
  41. Climate change: Water vapor makes for a wet argument
    scaddenp at 13:44 PM, Phil, what I was trying to do is examine the link between two things. The known relationship between water vapour and atmospheric temperature, and the contentious issue of the apparent current lack of increased solar output whilst temperatures are supposedly still rising. Whether the output of shortwave radiation by the sun varies or not, it is not the only factor that determines the energy that is absorbed by the land and sea surfaces, which must occur before it can then be radiated off as longwave radiation. Variation in clouds is a significant controlling factor which is readily observed over short time frames with indications of longer term trends. With water vapour, although there is a known relationship between the saturation point and temperature, the evaporation process is driven by other factors that are not necessarily directly tied to temperature, those being the direct input of solar shortwave radiation and wind. Even though the oceans cover a larger area than land, I used the example of what occurs on land as it is well measured and understood, and something that I assume has been observed by most people, especially those with more than a passing interest in the processes that drive both the weather and the climate.
  42. Quantifying the human contribution to global warming
    dana1981 I like the article as it explains things very clearly, yet I have a comment similar to what HR brought up. Putting on my skeptic hat now, the precision of scalar 5.35 gets my attention when dF does not appear to depend on temperature itself. CO2 back radiation (if it is even real) is supposedly a function of temperature (in this case that of CO2) and that of changes incident solar radiation. Basing the change of radiative forcing on a ratio such as C over Co implies "all things being equal" (including the amount of incident solar radiation). However while the overall model assumes natural changes in solar irradiance, the formula assumes this to be constant, which is fine for a first order approximation, however, what then is the basis of the (+- .005 W/m2) precision based on? Put another way, while dF is theoretically not independent from changes in average global temperature nor incident solar irradiance, the formula reflects this assumption in its simplicity, while at the same time includes a factor with a precision out to two decimals places. How real is all this for the minor changes in temperature we are talking about?
  43. Hurricanes And Climate Change: Boy Is This Science Not Settled!
    The Basic versions that have appeared thus far are pretty good, I think, given the limitations of the format. Maybe someone can now post a Basic version of what cities can do to deal with sea level rise.
  44. Arkadiusz Semczyszak at 17:23 PM on 3 September 2010
    Climate change: Water vapor makes for a wet argument
    Clouds also act as a buffer. High clouds such as the type cirrus - they are thin and have small albedo retain heat (long wave), in the tropics where high clouds are thicker, the albedo is higher - energy balance may be negative. At night, clouds not only retain but also to remove the energy - on its top surface - through the so-called: "thermal chimney". In high latitudes, "thermal chimney" is weaker than the effect of stopping energy through the clouds of radiation the Earth's surface - at night. In the tropics, such removal of energy - for example, are often very complex cumulonimbus (upward - until the tropopause and the stratosphere, even) can be even (so) larger than the energy of radiation stopped from the earth's surface. There should not be also consider the global energy balance cloud cover - although already a bit "already old" criticism on RealClimate, the tropics, can - through internal forcing of the Earth's climate system - significantly affect the size of the current warming. Not only as Mr Spencer says, but many researchers, in this and the IPCC (eg Solomon).
  45. Arctic sea ice... take 2
    Timothy Chase, My guess is that the author means thick ice takes a lot more heat to melt - simply because it is thick. In other words, we are talking about the heat needed to melt ice per square meter (surface), not per cubic meter (volume). As for salt and saltwater in the ice, there is almost no salt in sea ice once it is frozen.
  46. Sea level rise: the broader picture
    HR @72 - The satellite data for global sea level is inclusive of the period 2005- 2009 is it not?. Look at the graphic provided at @70 (from UCAR/NCAR) & the video from Kevin Trenberth. What acceleration are you referring to?, OHC has declined from 2005. Doesn't that go some way toward answering your question @72 & repeated again @74?. Unlike many skeptics, who are always dead keen to throw the baby out with the bath water, the missing heat concerns me. Many climate scientists, and I'm of a similar view, expect that there may be a few surprises the climate has in store - is this one of them?. Has some significant change occurred in the deep ocean that we're as yet unaware of?, and will (as Kevin Trenberth states) this come back to haunt us?. I hope not, but as far as I'm aware the "missing heat" has yet to be accounted for.
  47. Quantifying the human contribution to global warming
    #4, HR, keep in mind that on a fine enough granularity, everything is linear. The difference between a climate system at 300 degrees K, and 300.8 degrees K can be pretty well approximated by linear functions. In some places this isn't true, for instance at the freezing point of water -- there is a big discontinuity between a system that is at 0 degrees C and frozen, and one at 0 degrees C and thawed. That is why the arctic is such a big concern for climate scientists. Other aspects of the system may need to include non-linear effects, like the huge jump in CO2 in the past century or so. There are a large number of interacting factors that we are only beginning to understand. One can speculate, and one can extrapolate, and one can choose to believe whomever one wants to believe, but the reality is that we're running a gigantic uncontrolled experiment on the environment upon which we depend for our survival, and everything we understand about the science tells us that the situation isn't going to slow, stop, or reverse unless we change what we're doing. #6, Jim Meador, the water vapor feedback is included in the total climate sensitivity. It is a factor in the uncertainty in sensitivity that dana1981 cites.
  48. Quantifying the human contribution to global warming
    Well, the water vapor feedback in response to increasing CO2 should be contained within the climate sensitivity parameter.
  49. Sea level rise: the broader picture
    69 Peter Hogarth that's great Peter, I don't think I dispute what you write about the satellite record but I will hold you to a global, 18 year data set being a "relatively short record" when we clash over data sets in future posts. Please tell me why we don't see any acceleration in the satellite record.
  50. Sea level rise: the broader picture
    71 Ned Sorry I don't read what Jo Nova has to say. I'm prepared to accept your assessment of her as little more than a propagandist if you want.

Prev  2213  2214  2215  2216  2217  2218  2219  2220  2221  2222  2223  2224  2225  2226  2227  2228  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


© Copyright 2024 John Cook
Home | Translations | About Us | Privacy | Contact Us