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Comments 69501 to 69550:

  1. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    Yes, I was surprised. I had it in my head that there was real evidence of Greenland being significantly warmer at some point during the MCA, although the effect was localised. Does this mean that it was sufficiently localised not to cover the arctic too, or is my recollection wrong?
  2. Economic Growth and Climate Change Part 1 - Factors Influencing CO2 Emissions
    Kevin I doubt a 'zero' carbon economy will be as easy as you suggest. It will get progressively more difficult and expensive as renewable penetrations become higher, 'carbon leakage' becomes significant and we obtain diminishing returns from improving thermodynamic efficiencies further. I fear that in placing all our eggs in the same environmental technology basket we risk the same over optimism as when we predicted 'cheap' nuclear energy, routine space flight and artificial intelligence. I'm not saying these won't happen eventually but we need to combat AGW now to avoid tipping points, and our best chance is to tackle it on several fronts. Good points in posts 4 and 5. However, austerity tends to be relative not absolute. We already have more than enough in the developed world. It is hardly unreasonable to expect people to avoid waste and excess and a great deal of our GDP is just that, it adds little of true value but creates environmental problems. Even the so called green technologies can generate pollution especially if it is done on the cheap: pollution casts shadow over Chinese solar rare earth metals technology boom Yes carbon is not the only issue, we live on a finite earth with limited resources and sinks, perhaps we also have a responsibility to other species as well and the more we consume the greater stress we place on these habitats.
  3. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    WUWT claims that "during the peak of MWP glaciers were smaller than today" found here does not apply to arctic with very high certainty. Interesting to note, that on the graph above, arctic ice looks on average larger during peak WMP (1000-1300AD) rather than for LIA (1550-1850AD), although probably not statistically signifficant. Still, from that observation with counter-intuitive outcome, we can say that both MWP and LIA were local events while arctic ice could have enjoyed different conditions.
  4. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    The BEST confirmations, Climategate 2.0 looking like a squib, and now yet another bloody Hockey Stick! Not looking to be such a festive season for some, is it? ;-)
  5. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    The "Ice Hockey Stick." Startling stuff but are we truly surprised?
  6. The Debunking Handbook Part 4: The Worldview Backfire Effect
    Shibui, 'skeptics' seem to be able to believe just about any nonsensical thing... so sure, I suppose they could see the hockey stick as 'confirmation bias'. It just wouldn't make any sense given that it has been replicated by numerous studies, analyzed and confirmed by the NAS, and even matched by a few 'skeptic' analyses that set out to disprove it. All of which demonstrates the very opposite of confirmation bias, but that isn't going to stop 'skeptics' believing otherwise.
  7. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    Tom Curtis @ 12 - that brings back memories. Is that now a "skeptic" training video?
  8. Economic Growth and Climate Change Part 1 - Factors Influencing CO2 Emissions
    Yes perhaps we should stick closer to the topic. Adelady. Yes there are other factors affecting population growth. In India the low proportion of females to males born is yet another, which will of course reduce population growth. However, it is notable that all of the methods if overdone could lead to social or economic instability in later years.
  9. The Debunking Handbook Part 4: The Worldview Backfire Effect
    Don't John or Stephan feel that the Hockey Stick could be seen by sceptics as an example of Confirmation Bias?
  10. Climate sensitivity is low
    Eric (skeptic) @245, the rapidity with which a system adjusts to a new equilibrium depends not just on thermal inertia, but also on the magnitude of the disequilibrium. With the enhanced greenhouse effect, the disequilibrium is small, being approximately 1 W/m^2. This is because of both the small initial perturbation and the fact that the full effects of positive feedbacks are not felt until the system approaches the equilibrium temperature. In contrast, in the model analyzed by Lacis et al, the initial perturbation is around 30 W/m^2. Consequently the system adjusts towards equilibrium much faster because of the much larger disequilibrium. Even so, as skywatcher @246 points out, the system has still not reached equilibrium after 50 years. Further, Lacis et al state that they use the Q-flux ocean model with a 250 meter mixed layer depth. Had they used a model with deep diffusion, time to equilibrium would have been significantly extended (by a few centuries, I suspect), but the early changes of the system would have been unaffected. It just would have taken longer to close the last 0.1 W/m^2 of disequilibrium.
  11. Climate sensitivity is low
    Depends what you call equilibrium Eric - the temperature units on the Lacis diagram are pretty large, and it clearly hasn't reached perfect equilibrium even after >50 years. Why you suggest it supports a 10 year equilibrium mystifies me. From the diagram the change has reduced to being relatively slight after ~25 years, but equatorial regions are still cooling after 50 years.
  12. Newcomers, Start Here
    Eric (skeptic) @151, no it means it is a very weak positive feedback. By reducing the difference between polar and tropical temperatures it makes the escape of energy from Earth less efficient. Because the energy escape is less efficient, the global means surface temperature must be higher for the same amount of energy to escape. However, this effect is so small (for the temperature changes involved) that it is extremely dubious that it could be detected against background noise in the coming century.
  13. Newcomers, Start Here
    No, it's a positive feedback (less uneven -> less radiation -> more warming)
  14. Newcomers, Start Here
    Tom, you said "Bodies with very uneven temperatures radiate heat far more efficiently than bodies with very even temperatures." Does that mean that polar amplification (makes temperatures less uneven) is a negative feedback?
  15. Climate sensitivity is low
    A quote from the Climate-time-lag.html article: "How long does the climate take to return to equilibrium? The lag is a function of climate sensitivity. The more sensitive climate is, the longer the lag. Hansen 2005 estimates the climate lag time is between 25 to 50 years." While reading through Lacis et al regarding CO2 as a control knob, I noticed this diagram

    Taking less than 10 years to cool to equilibrium suggests a short lag. That is for full removal of CO2, etc and I don't know if the time constant would be different for a change in CO2. But if the lag time is much shorter than the 25 to 50 years suggested above, then climate sensitivity is also lower than estimated by Hansen.

  16. Newcomers, Start Here
    Eric (skeptic) @146, yes, imthedragon's point @141 is correct, if easily misinterpreted. In the absence of an atmosphere and ocean to both retain heat due to their heat capacity, and to spread heat around due to the motion of winds and currents carrying heat from the tropics to the poles (and to a much lesser extent, from day side to night side, the Earth would suffer similar diurnal temperature variation to that encountered on the moon, ie, between -157 degrees C and 100 degrees C. Instead of that 257 degree C range, we have diurnal temperature ranges of between 5 and 30 degrees C (approximately), and that is almost entirely due to the capacity of the atmosphere and ocean to absorb and retain heat. What is more, that capacity also warms the Earth. Bodies with very uneven temperatures radiate heat far more efficiently than bodies with very even temperatures. For example, even though the effective temperature of the moon, ie, the temperature it would need to be to reradiate the energy absorbed from the sun to space if it was all one temperature, is around 380 degrees C, its blackbody temperature is actually 270 degrees C. The difference is due to the very uneven temperatures on the moon. However, this has nothing to do with the 33 degree C difference between Earth's effective temperature and its mean surface temperature. If the Earth was of uniform temperature with no greenhouse effect, its surface temperature would be 255 degrees K. As the Earth's temperature is not entirely even, it would actually be slightly lower than that, a fact often ignored for simplicity. But without the greenhouse effect, the surface temperature could not be raised above the effective temperature, let alone by the 33 plus degrees that it has been raised. So, yes, the atmosphere apart from the greenhouse effect makes the Earth's surface temperature stable. And yes, the greenhouse effect does nudge the temperature higher. But the 33 degree K (12%) nudge is more than just a bit, and indeed is absolutely crucial to the possibility of life on Earth.
  17. The Debunking Handbook Part 4: The Worldview Backfire Effect
    Steve, I wouldn't put Myers approach to humiliation on the same footing as your 'concern trolls'. I'm not fond of humiliation as a teaching, tutorial or discussion technique, but I know it has many adherents and a long, not-so-glorious history in universities. It's an extension of not suffering fools gladly. Probably marginally useful in training where people are looking to enter professions (in medicine or the military for instance) where clear thinking and rapid judgments can be crucial. I see it as a form of intellectual bullying. Mainly because it tends to become an habitual, charmless style rather than an occasional startling wake-up call. It's only saving grace is that it's honest. The same cannot be said for the 'concern trolls'. Where I see such interventions in discussions, I'm prepared to bet my wardrobe that it's the thin end of a wedge which generally finishes up going in a very unpretty direction.
  18. Newcomers, Start Here
    I think I can answer one of my questions. Pressure broadening in wikipedia is "Impact pressure broadening: The collision of other particles with the emitting particle interrupts the emission process, and by shortening the characteristic time for the process, increases the uncertainty in the energy emitted (as occurs in natural broadening)[3]. The duration of the collision is much shorter than the lifetime of the emission process. This effect depends on both the density and the temperature of the gas." Apparently the heating of the rest of atmosphere by GHGs is one part of pressure broadening. Then the other effect of the rest of the atmosphere is stability from thermal inertia. Both imthedragn and I may have been conflating warming and stability.
  19. The Debunking Handbook Part 4: The Worldview Backfire Effect
    Question: Those of us most interested in the science are upset about political attacks on science and personal attacks on scientists. It happens that a lot of those attacks come from members of given political parties and people with strong political leanings, so a lot of us might identify those parties and leanings as being our enemies. Does this simple identification hurt our chances? Scientists may say, "The world is very likely X and it is very unlikely Y." Then someone jumps in from Political Group A and generalizes on the basis of their own conservation bias, "Yeah, those stupid Political Group B people are all idiots and deny logic and science." Are these people hindering progress by increasing the defensiveness with which anyone who identifies with Political Group B will approach the topic? Should we be trying to censor such supporters of science? Should we censor ourselves when identifying groups who resist the finding that "The world is likely X" and inhibit the dissemination of that finding? To make this 'real' in the context of internet discussions, are the 'concern trolls' correct about tone? Is PZ Myers wrong about the value of humiliation?
  20. Newcomers, Start Here
    Thanks skywatcher, I read the paper, but it merely repeats Tom's explanation about pressure broadening (as shown in Tom's diagram above). Is the lapse rate responsible for the 33C GH effect? If so, are changes lapse rate caused by uneven pressure broadening of increased CO2 (with more broadening at the bottom)? Seems like a valid but only partial explanation. What about heat transferred from CO2 to O2 and N2? I do not believe that can be ignored for both stability and warmth.
  21. Economic Growth and Climate Change Part 1 - Factors Influencing CO2 Emissions
    Back to the issue of economic growth influencing CO2 production, a headline in our local business section says "Oilsands output could triple by 2035", citing a report by the National Energy Board (Canada). Included in the article was a comment from the Pembina Institute that the government had to address mounting environmental challenges if Canada was to reach its 'energy potential'. So far it seems that economic growth is the main consideration.
  22. Economic Growth and Climate Change Part 1 - Factors Influencing CO2 Emissions
    MA Rodger#19: "Hansen & Sato 2004 see the wobbly soak-up rate as important enough to spend one page of a six page paper discussing it." Not so much. Here's H&S' main point on that question: Year-to-year fluctuations of atmospheric CO2 growth must reflect fluctuations of the land and ocean sinks for CO2 and the biomass-burning source. Most of the rest is about other GHGs. "40% is a more usual number" Is it? Again H & S: Fig. 5A shows the CO2‘‘airborne fraction,’’ the ratio of the annual increase in atmospheric CO2 to annual fossil fuel CO2 emissions. Despite large year-to-year fluctuations, the airborne fraction has been remarkably constant at ~60% of emissions during the post World War II period Nor is there any mention of ENSO or either NinX in this paper. Again, I'm not seeing the point of this wobblometry.
  23. Newcomers, Start Here
    Eric, on temperature stability, I'm not sure what your point is. Have you read the Lacis et al paper DB linked to inline at #141? The remaining atmosphere without GHGs can provide a stable temperature ... if you like your temperature to be stable at -21C! Given the lack of water vapour in that atmosphere, I suspect the diurnal range would be pretty brutal round the mean figures too, though cloud cover would tend to moderate it.
  24. The Debunking Handbook Part 4: The Worldview Backfire Effect
    "Another way in which information can be made more acceptable is by “framing” it in a way that is less threatening to a person’s worldview. For example, Republicans are far more likely to accept an otherwise identical charge as a “carbon offset” than as a “tax”, whereas the wording has little effect on Democrats or Independents—because their values are not challenged by the word “tax”.6" Somebody should really forward a copy of this to the Labor strategists that allowed the "carbon tax" to become the commonly accepted way of referring to the policy.
  25. Newcomers, Start Here
    Tom, my understanding is that the CO2 more or less immediately transfers energy from outgoing IR to the rest of the atmosphere. Wouldn't that heating of N2 and the O2 raise the temperature of the atmosphere from bottom to top (more at the bottom) and thus explain the higher lapse rate? Another way to look at it is that the overall mass of the atmosphere dictates the heat capacity but additional CO2 raises it slightly. Thus I think that imthedragn's point about temperature stability (141) is valid.
  26. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    The bottom line: Hacked emails are a sideshow and cannot take away from what many business leaders already know and what the IPCC’s extreme weather report confirms. Climate change is real and we’d better buckle our seat belts for more costly extreme weather if we carry on with business as usual. Source: “IPCC Report Confirms What Businesses Already Know: Extreme Weather & Climate Change Has Economic Impacts” by Mindy Luber, President of CERES, Forbes, Nov 23, 2011 Click here to access this article.
  27. Economic Growth and Climate Change Part 1 - Factors Influencing CO2 Emissions
    MA Rodger - sorry to butt in here, but I'm just joining in near the end of this to-and-fro. You are aware that ENSO affects atmospheric CO2 because of the extra rain that falls over land during La Nina stimulates vigorous plant growth, and cooling of sea surface temperatures? Conversely El Nino warms the sea surface (particularly the equatorial Pacific) which increases CO2 outgassing from the ocean, and the marked drying of the tropical basins diminishes plant growth, and therefore they too give up CO2 to the atmosphere. Volcanic eruptions tend to ramp up CO2 uptake by land-based plants because the diffraction of sunlight enables light to better penetrate the forest canopy. If none of this has anything to do with what you guys are debating, please disregard.
  28. Newcomers, Start Here
    Sphaerica, with respect, I believe your explanation @143 is incorrect. Placing imthedragon's question into context, the Earth's atmosphere contains just 8% of the CO2 contained by Mars'atmosphere. Further, CO2 provides approximately 20-25% of the greenhouse effect on Earth, or about 7 degrees C of warming. If the Earth's CO2 was doubled 3.5 times it would equal Mars' CO2, so on a simplistic view, Mars' greenhouse effect should provide about be 11 degrees warming. That is approximately double the warming it actually provides. A major reason for the shorfall is the lack of pressure broadening. Increased pressure widens the absorption band at the expense of reduced probability of absorption in the central peak. (From Science of Doom) Because in the central peak the atmosphere of both Mars and Earth have an optical thickness greater than 1, the effect of reducing pressure is to increase the altitude of effective emission from CO2 to space. However, it also greatly reduces the bandwidth of that emission, thereby allowing far more heat to escape directly to space from the surface, thereby greatly reducing the greenhouse effect. Mars' surface pressure is 4 to 8.7 mb (depending on season), so the effect is far greater than that illustrated in the diagram above. There are two other significant effects reducing the greenhouse effect on Mars. The first is that the adiabatic lapse rate on Mars (4.5 degrees C per km) is less than half of that on Earth, and significantly less than the environmental lapse rate of approx 6.5 degrees C/km. By itself, this factor would reduce the strength of the greenhouse effect on Mars by about 30%. The second is simply the other gases in the atmosphere. Given a layer of CO2 sufficiently thick to absorb all IR light in its absorption band, if we add another gas that does not absorb IR sufficient to double the atmospheric pressure, the thickness of that layer of CO2 increases. In doing so, the effective altitude of radiation of that CO2 also increases. The strength of the greenhouse effect is most simply calculated by assuming that the temperature at the effective altitude of radiation to space equals the equilibrium temperature of the planet (ie, that temperature which will result in outgoing radiation matching incoming radiation), and then deriving the surface temperature by the lapse rate. Increasing the effective altitude of radiation by adding neutral gasses therefore increases the strength of the greenhouse effect. Consequently, the large concentrations of oxygen and nitrogen on Earth increase the strength of the greenhouse effect on Earth relative to Mars, in addition to the other effects. As a final note, while adding neutral gases does increase the strength of the greenhouse effect, they do not have a direct effect on surface temperature (other than by equalizing the distribution of temperatures). In the absence of a greenhouse gas, adding neutral gases would have no ability to raise surface temperatures above the equilibrium temperature as greenhouse gases do.
    Moderator Response: I suggest adding an Argument: "Why is Mars so cold when it has so much more CO2?" Include not just these reasons, but also an explanation that (and why) the amount of energy from the Sun reaching Mars is so much smaller than that reaching Earth. And give it a link to the Mars is Warming argument.
  29. Economic Growth and Climate Change Part 1 - Factors Influencing CO2 Emissions
    @18 The links have picked up extranious characters. They are in order:- http://www.esrl.noaa.gov/psd/enso/mei/table.html http://cdiac.ornl.gov/trends/emis/meth_reg.html
    Moderator Response: (Rob P) Had to excise your last link, it was messing with the page layout.
  30. Economic Growth and Climate Change Part 1 - Factors Influencing CO2 Emissions
    Muoncounter @17 Hansen & Sato 2004 see the wobbly soak-up rate as important enough to spend one page of a six page paper discussing it. It is as you say but an oscillation on a rising trend but big enough to reduce annual increases by 70% in consecutive years. The causal link – high MEI will restrict ocean absorption of CO2, low MEI will assist it setting the CO2 wobble in motion. (One comment – I was surprised to see the 55% figure for CO2 remaining in the atmosphere on your second graph @14. 40% is a more usual number. I linked back to the graph's origin & CO2 data source & saw two problems. The USEIA CO2 data is a bit low but more worrying, the emissions for land use change appear not to be included in the analysis.)
  31. Economic Growth and Climate Change Part 1 - Factors Influencing CO2 Emissions
    Sphaerica @16 You're asking a bit too much here. The lag (always present) is variable in length and perhaps could be due to the season the El Nino/La Nina occur in. Also the ampitude. Or whatever. That use of an index like MEI comes so close to the CO2 rises with only a starightforward linear re-scaling I fine pretty impressive. And getting a better fit would require a step into the modelling arena, a major piece of work. The “2002 on” section – I wonder that if the next El Nino sees CO2 rises passing well above 3ppm pa, those wobbles wouldn't then look so odd. Your requested 'third line' will require a mix of annual data & monthly data so this is a little more of a task than something done over a cup of tea. And I do wonder what would be gained by plotting CO2 emissions as a separate line. If this does gain a place on my to-do list, I would see more to be gained by subtracting the emissions increase to leave the wobble without the trend. (Of course, it doesn't have to be me that creates the graph when the data is available to all.) MEI data monthly CO2 data CO2 emissions – FF & cement CO2 emissions – land use
    Moderator Response: [Sph] Links fixed. When you post links, try not to use "curly" (“curly” instead of "straight") quotes (or to copy from Word, which tends to automatically give you curly quotes). They aren't the same (to HTML) as straight quotes, and hence the problems (the "extraneous characters" were the curly quotes themselves).
  32. Bert from Eltham at 11:38 AM on 24 November 2011
    Pielke Sr. Misinforms High School Students
    I wonder if Pielke would think that it would be quite acceptable for me to urinate and defecate in my or any other street. Or maybe his street or front yard. Could I just throw my rubbish anywhere I liked? Say out in the same street. Surely as I am only some miniscule proportion of any large group this would not matter? There is no linkage proved with my waste and any disease or annoyance. So if we all did this and put billions of tonnes of this waste into the environment it has absolutely no harmful effect! My body waste and rubbish are very nutritious foods for all sorts of living things such as plants and bacteria and will neatly add to productive food for all! In the middle ages people used to throw their rubbish into the street and waste ran down the gutters. It did them no harm in fact they flourished along with rats and other benign native animals. They even grew grapes in Scotland! We just do not need sanitation or clean water as it costs far too much. Anyway nature or providence will take care of it. There is no evidence that all this expenditure will make an iota of difference! All these people worried about 'pollution' are just anally retentive. They have a secret agenda for world domination by regulating our lack of anal retention. Bert
  33. Economic Growth and Climate Change Part 1 - Factors Influencing CO2 Emissions
    MA Rodger, I'm not seeing the point of this wobblometry. Hansen and Sato's 2004 analysis was reproduced here by D. Kelly O'Day. If you are suggesting there's some sort of causal relationship between MEI and deltaCO2, what is it and why does it work? And why would that be important, as it is little more than an oscillation on a rising trend?
  34. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    lurgee -- "Thus far, the most 'exploitable' line seem to be Phil Jones's comment about the IPCC being above national FOI requests, which seems a reasonable enough statement when referring to an international body" I'm sure that's covered in the first set of emails and jumped on by denialists last time (Caspar Amman, IPCC?), but probably just an email that wasn't cherrypicked for the first release. Zombiegate/Sloppy-seconds-gate/Whatevergate. Same crap, different conference.
  35. Economic Growth and Climate Change Part 1 - Factors Influencing CO2 Emissions
    MA Rodger, What about 2002 on? What about amplitude, as well as an apparent "lag" in some cases but not others. Your eyecrometer seems to be malfunctioning. You are seeing strong correlation and stopping your thought process dead because, in your mind, it's "close enough." Again, why only include those two variables on your graph? Add emissions, then you can make your case more clearly and completely.
  36. Economic Growth and Climate Change Part 1 - Factors Influencing CO2 Emissions
    Sphaerica @14 My apologies but I'm at a loss what you mean by "a lot of major disconnects." This leads me to wonder what you are defining as "short-term". The CO2 increase trace is characterised by a series of wobbles superimposed onto a rising trend of increasing slope. With the exception of the volcano years (63, 82 &91) the MEI matches the CO2 wobble for wobble with perhaps the exception of 2005-8. If the wobbles are the short-term features, surely ENSO represented by MEI is "the major short term factor." That's where I'm coming from. Until I can grasp where you're coming from, thoughts of "a third line" (which will require the use of annual data on a month graph) would be premature.
  37. Newcomers, Start Here
    141, imthedragon,
    So it is really the atmosphere and not greenhouse gasses that provides the stability of the temperature...
    No. You are very grossly understating the role of greenhouse gases. As you already pointed out H2O is a very strong greenhouse gas and, as both skywatcher and I have explained, it dominates near the surface. So where do temperatures vary the most on earth, in a desert or in a rainforest? The latter has nice, cool trees to shade you, and yet it is stiflingly, achingly hot during the day and gives you little respite at night, too. The desert has burning sands in the day, but temperatures plummet at night. The difference lies in water vapor, the powerful greenhouse gas, that is pervasive in a tropical rain forest and prevents it from losing heat, but almost totally absent in a desert and so allows the heat to escape the moment the sun goes down.
  38. Newcomers, Start Here
    140, imthedragon,
    CO2 and water vapor both absorb infrared from a nearly identical portion of the spectrum
    This is wrong because, just like the radiation/collision aspect of things, the system is far more complex than that. It's not nearly as simple as just saying they overlap, so the change can't matter. For example, the concentration of CO2 proportionally in the atmosphere is fairly constant regardless of altitude, while the concentration of H2O drops the higher you go, because temperatures drop as you get higher and the ability to hold moisture in the air is temperature dependent. Why does this matter? Because a big part of what is changing, and causes greater surface temperatures, is that the altitude from which the planet radiates away its energy is increasing. The earth must have a mean global temperature of 255˚K when seen from space. It must, because that's the amount of energy that it absorbs from the sun. That can't change. What can change is the distribution of energy beneath the point where it radiates the energy into space, and the altitude where the radiation occurs. Picture the atmosphere, for the sake of argument, as a series of layers. Every layer absorbs IR, gets warmer, and radiates IR up and down. Above the lowermost layer, every layer is receiving IR from above and below. As you go up the air is less and less dense, with proportionally less H2O and the same concentration of but less total CO2. So as you go up more and more IR succeeds in radiating upwards, working it's way out into space, rather than downward and warming the surface. When there is less CO2, the layers above have less chance of trapping the outgoing energy. The radiation to space effectively occurs at a lower altitude. With more CO2, the layers above trap more radiation. Things progress upward, and the ultimate radiation to space occurs from higher layers. Add H2O, which overlaps with the CO2 absorption range. But H2O is not evenly distributed. It is more present in the lower layers, and more rarefied in the upper layers. So if you add CO2, and radiate the energy into space from high enough up, the overlap of CO2 and H2O is irrelevant. CO2 dominates.
  39. Newcomers, Start Here
    #140 imthedragon - it's important to remember that, although there's overlap between CO2 and water vapour, one condenses and precipitates at Earthly temperatures and one does not. Additionally, in the upper atmosphere, it's the radiation from CO2 that dominates due to pressure effects (see for example this RealClimate article or this excellent series by ScienceOfDoom). So while it's tempting to think of CO2 and water vapour similarly, you cannot, as one is doomed to be a feedback to the other's forcing, and one is not so prevalent or effective in the thin upper atmosphere.
  40. The Debunking Handbook Part 4: The Worldview Backfire Effect
    I notice that advertising companies have picked up on this. Can't remember the company (I've already got mine) but "I'm not trying to save the world. I'm just saving up for a trampoline." is advertising genius.
  41. World Energy Outlook 2011: “The door to 2°C is closing”
    Suggested reading: “Climate-Control Policies Cannot Rely on Carbon Capture and Storage: That’s My Side of The Economist Debates” by Joe Romm, Climate Progress, Nov 22, 2011 Click here to access this article.
  42. Newcomers, Start Here
    So it is really the atmosphere and not greenhouse gasses that provides the stability of the temperature. Instead of frigid cold overnight and scorching heat during the day, the temperature stays more moderate because of the atmosphere even if the atmosphere were devoid of greenhouse gasses. The additional heating of the greenhouse gasses by their absorbtion of the infrared radiated from the planet's surface allows that average temperature to be nudged a bit higher.
    Response:

    [DB] "even if the atmosphere were devoid of greenhouse gasses"

    Umm, no.  Please read Atmospheric CO2: Principal Control Knob
    Governing Earth’s Temperature

  43. Newcomers, Start Here
    Sphaerica, that is by far the best response I have ever seen to that question I had of Mars. The fact that surface temperatures are both much cooler and much warmer than they would be otherwise and that the "global warming" simply refers to the shift in those average temperatures really puts things in perspective form me. The remaining item in my mind that I need to clear up is defining a "static" greenhouse effect. By that I mean if we raise the CO2 level by x amount and then keep it there perpetually, the global average temperature will eventually stabailize to what. In my mind, regardless of how much you try to categorize things as forcings or as feedbacks, CO2 and water vapor both absorb infrared from a nearly identical portion of the spectrum, I still conceptualize them as if they were acting as a single gas.
  44. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    Suggested reading: Real 'Climategate' Scandal: UK Police Spent Measly $8,843 In Failed Attempt to Identify Criminal Hacker” DeSmog Blog, Nov 22, 2011 Click here to access this article.
  45. Economic Growth and Climate Change Part 1 - Factors Influencing CO2 Emissions
    12, MA Rodger, I see a lot of major disconnects in your graph between MEI and CO2, which clearly points to MEI being only one factor, and not in any way the major short term factor in comparison to emissions. Clearly there is something missing, and changes in actual emissions are the obvious candidate. You should amend your graph to clearly include a third line demonstrating actual human emissions each year.
  46. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    Suggested reading: “East Anglia SwiftHack Email Nontroversy Returns: What You Need To Know”, DeSmog Blog, Nov 22, 2011 Click here to access this article.
  47. Newcomers, Start Here
    138, imthedragon, The thinner atmosphere is crucial. People often get so caught up in the radiative aspects of CO2 (and other greenhouse gases) that they lose track of the collisional transfer of energy. In the Martian atmosphere there is little to be heated except for the CO2 itself, so radiation dominates, and energy transfer up and out is quick, even if it must "make some stops along the way." In the Earth's atmosphere a very, very important piece of the puzzle is that closer to the surface, where the air is denser, CO2 absorbs IR, but before (usually) it is able to re-emit that energy, a collision with O2 or N2 transfers that energy to those molecules, which do then not as easily or as readily emit energy in the infrared. The end result is that surface radiation heats the CO2, and the CO2 heats the surrounding atmosphere. As one gets higher and higher in altitude the atmosphere becomes less and less dense, and the balance shifts, so that eventually radiation becomes the key factor, and CO2 acts to cool rather than to warm (i.e. collisions between O2/N2 and CO2 transfer energy from the O2/N2 to the CO2, which is then emitted as IR and potentially lost to space). Admittedly, this interaction is not crucial to the greenhouse gas effect (see Venus, which has roughly the same proportion of CO2 in the atmosphere, but where the atmosphere is far more dense and the GHG effect still dominates). But it is important to what happens on Earth, and to understanding some of the differences between the Earth, Mars and Venus.
  48. Newcomers, Start Here
    GREAT comments gentlemen. Look again at Mars. The realtive amount of CO2 is higher (by several thousand percent), but the absolute amount of CO2 exceeds that of the earth in excess of 10 fold. The thinner atmosphere effects the ability to retain heat. It also effects the "well mixed" amounts of CO2 in the dry upper atmosphere the same way. where the air is half as thin, the greenhouse effect of CO2 at that altitude is less than half (no idea by how much, just believe it not to be a linear realtionship)
  49. The Debunking Handbook Part 4: The Worldview Backfire Effect
    Wikipedia has a nifty list of human biases http://en.wikipedia.org/wiki/List_of_cognitive_biases
  50. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    29, Albatross, I would note that when the problem ripens, and adaptation is required because hesitant, faltering, too-little-too-late mitigation has failed, the rich countries will successfully if not easily adapt as well they can, armed with reasonably robust economies, infrastructures, industry and technology. The poor countries (and poor people within rich countries) will adapt as people traditionally have, by up and moving. Mass migrations, refugees, population culling by starvation and resource wars, and more will be the adaptive tools of the poor, developing countries. Everyone will adapt, just in different ways.

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