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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.

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Comments 127501 to 127550:

  1. Are humans too insignificant to affect global climate?
    Nice little post, John. It is instructive to integrate your Figure 2 to get the cumulative CO2 emissions into the atmosphere. The correspondence with the secular trend in CO2 concentrations in the atmosphere is very impressive indeed. pdt--the result of increasing CO2 concentrations is an increase in ocean acidity. There are many links to this topic. One place to look is http://www.pmel.noaa.gov/co2/OA/ . Or just start with Wikipedia.
  2. How we know global warming is happening, Part 2
    Thank you for this great post. I will be updating my site with much of this information. :)
  3. Are humans too insignificant to affect global climate?
    Where does the other half go? How much in the oceans? Is that measurable? If so that part should count as climate too, at least for lifeforms that live in the ocean.
  4. How we know global warming is still happening
    It is curious that "science" promotes the idea of evolution, and yet scientist are wishing to stop it. A changing environment leads to natural selection which implies no control. Is Darwin in charge or not?
  5. Are humans too insignificant to affect global climate?
    Good post John. Another piece of evidence as to how we are changing the atmosphere is the reduction of O2 as the CO2 increases (burning uses up O2). While the change as a percentage of all the O2 in the atmosphere is extremely small, we have been able to observe the decrease for the last 20 years or so. A good article on it here. As an interesting note, in the article Keeling estimates the increase in sea level from the H2O produced by burning hydrocarbons. As you would expect the number is very small. Best, John
  6. How we know global warming is still happening
    It is not a given that there are more clouds in a generally warmer environment. Cloud formation depends very much on relative humidity and also the availability of lift within the atmosphere, warm moist air must rise and cool to near it's dew point. A product of all climate simulations is a near constant relative humidity as the climate warms. Look at the tropics and near tropics today. Most cloud formation is convective in nature and where this is the result of daytime heating the clouds dissipate at night. The tropics receive the vast majority of solar radiation but cloudiness does not prevent that region from being the warmest on Earth. If the climate zones and jet streams are shifted poleward in a warming world why would the dynamics be any different in their displaced positions?
  7. Philippe Chantreau at 20:03 PM on 6 October 2009
    How we know global warming is still happening
    And whence do you infer that this is not well known of climate science, inappropriately modeled and inconsistent with observations? The water vapor/clouds feedback is a matter of much debate and, in any case, still a feedback from warming triggered by increased GH effect. Furthermore, increased cloudiness at higher temperature would seem to require a lowered relative humidity and I'm not sure whether we're seeing that. Models appear to argue against it. One fellow skeptic recently trumpeted the Trenberth and Fasullo paper suggesting that cloud feedback might actually be much lower than previously modeled, leading to a lot of extra warming from increased solar irradiance reaching the surface. For all the hooplah demonstrated by that fellow skeptic, it's worth pointing that the HADCRU model is in fact fairly close to Trenberth'runs, and HADCRU long term prognostic is not that different from GISS. It is also worth reminding that the decreased cloudiness of Trenberth' model runs was still a feedback of increased GH warming. Much a do about nothing.
  8. How we know global warming is still happening
    What follows is an excerpt from an article found here http://physicsworld.com/cws/article/print/17402 "The spectroscopic data that are required to model long-wave atmospheric absorptions are generally well characterized. When these data are put into atmospheric models, water turns out to be responsible for about 60% of the greenhouse effect, while the much-reviled carbon-dioxide molecule accounts for just 26%. Ozone accounts for 8%, and methane and nitrous oxide - the atmospheric concentrations of which have been increased by human activity - contribute a further 8% to the greenhouse effect. " The article goes on to say that the warmer the Earth gets, the more water vapor and therefore the more clouds that shield incoming Sun. Probably that is why we are still here to talk about this.
  9. Are humans too insignificant to affect global climate?
    Do we (you) know John if the difference between what we are producing and what is being dealt with is increasing? You would expect it to be with deforestation and drought on the one hand, and the changing capacity of the warming and acidifying oceans to keep absorbing CO2 on the other.
    Response: Good question. Figure 7.4 in the IPCC AR4 shows a graph of the fraction of fossil fuel emissions remaining in the atmosphere (‘airborne fraction’) since 1958 (the thick black line is the 5 year mean):



    Bit early to tell whether there is a long term trend there.
  10. The link between hurricanes and global warming
    Some Science! Global warming theory actually predicts strongest warming in the Arctic and secondary the Antarctic, with little change in middle to lower latitudes for several years, or decades. The idea that mid latitude storm intensities, tropical system enhancement, and severe weather events would be minimal due to less baroclinic stress (a decrease in solenoids) or less atmospheric density differences over a horizontal distance, ...if CO2 were actually causing major changes in the atmosphere. If such changes are taking place, must be from other forcing factors (maybe solar intensity fluctuations, and related magnetic flux changes). The weather should, at least if we assume CO2 warming is dominating, becomes more benign, with some trend toward increased moisture in the normally dry Arctic. Mid latitudes will be largely unaffected, and the tropic certainly not affected. The numerical models all, I repeat ALL, have parameterized processes that are very subjective,not directly included in the quasigeostrophic computations, and contribute strongly to errors in the computational output of said models. Algebraic coefficents, or fudge factors, then become necessary, largely ruining the value of the forecasts.
  11. How we know global warming is still happening
    RSVP, in addition to the known multiple forcings in addition to CO2, the positive feedbacks are strong contributors. The temperature rise is a consequence of all of that, not just CO2.
  12. Philippe Chantreau at 16:07 PM on 5 October 2009
    How we know global warming is still happening
    RSVP, the Earth is not a closed system, no matter how you cut and slice it. Any way to look at it as a closed system is wrong. Your own water jug analogy describes an open system. "I believe something else is going on." What is? What quantitative analysis are you basing this on? In which science papers has this analysis been published? The warming effect of CO2 alone is fairly well known, based on radiative physics. There is more debate on the feedbacks, which condition the total sensitivity. Which part of that exactly does not add up for you and, again, what quantitative analysis is there to support your doubts? Considering the vocation of this site, I'd like to see science publications as support.
  13. How we know global warming is happening, Part 2
    Riccardo, my point was that some of numbers quoted above refer to the Earth as a whole(Hansen & Trenberth) while Schuckmann is talking about the oceans only. That was not particularily clear above. Cheers, :)
  14. How we know global warming is still happening
    So, correct me if I am wrong in understanding your reply, you are saying basically that processes are non linear and to a point self limiting, and (perhaps implied) generally driven by the Earths distance from the sun, its rotation, etc. And that our burning of fossil fuels are taking the mean temperature upward. I dont see this as unreasonable, and my opinion isnt going to keep the Earth any cooler.... ...however. I am not so convinced that its just the CO2 that is the culprit. I came to this website in the first place because of an independent discussion about what a relatively mass concentration CO2 has in the atmosphere and how could it possibly be taking the Earths temperature up. I believe something else is going on besides the incremental heat trapping effect of CO2, and that if nations only attack this issue, it may be just a big waste of effort and time.
    Response: CO2 isn't the only thing going on - there are a number of forcings that affect climate but CO2 is the dominant forcing:

  15. How we know global warming is still happening
    RSVP, you are correct that if the Earth's input and output were in equilibrium before and after the temporary reduction in input, then afterward the system would indeed remain at a lower temperature. But the Earth's (the whole thing including the atmosphere, seen from outer space) input and output were not in equilibrium before, say, Mt. Pinatubo's eruption. The input was outpacing the output. (The water level in the jug was increasing.) This is where the jug analogy breaks down, because the Earth's rate of output to space increases with the temperature of the Earth. You'll have to pretend that the jug's hole lets more water out the more water is in the jug. The Earth's temperature was on its way up toward a new equilibrium output to suit its new, higher, equilibrium temperature. Then the eruption reduced the input a little bit, for a little while. That was enough to slow down the system's progress toward its still-not-reached equilibrium output rate and temperature. After the aerosols cleared, the system continued to heat up (and to increase its output rate) still in pursuit of that before-eruption equilibrium temperature and output rate. Actually, the system's goal equilibrium temperature and output rate post-eruption are lower than they were pre-eruption, because the amount of heat in the system is lower (slightly); but those new, lower goals still have not been met, so the system continues to heat on its way toward that new goal. Meanwhile, of course, the output rate is being reduced by a factor independent from all the above: The greenhouse gasses continue to increase. (Moss is growing to block the hole in the jug.) That moves the equilibrium goal even higher, continuously. The system never reaches its equilibrium goal.
  16. How we know global warming is still happening
    In the analogy of the water jug, the level of the water is the Earths temperature. Water dripping in is incoming radiation. Water flowing out is outgoing radiation. If outflow is reduced the level will rise. I dont think this is different from the idea that CO2 is causing less heat to escape the Earth. Now assuming a perfectly balanced flow situation for the jug where the level never changed at 3 gallons, this would be analogous to a level of CO2 in the atmosphere wherever nature had it say 500 years ago or so. But now someone comes along and removes one gallon, which would be like volcanic ash blocking the sun in a big way for 3 years. The two gallons left would be like the temperature of the Earth dropping to say ice age conditions. As I describe, there is no reason for the water level to come back to 3 gallons. It will remain at two gallons forever unless the flow rates are altered. Similarly, after ten years, all the volcanic smoke clears, and the atmosphere is pristine again. The sun shines as before, and the processes preceding the eruption take over. The temperature should stay where it is. So far, no one has provided an answer that explains why global temperatures go back to "normal" in terms of the CO2 mechanisms described to explain recent global warming. An explanation of this type would require excess CO2 following the eruption, and CO2 subsequently reducing over time to reach stasis. However, the data supposedly shows the opposite. That CO2 rises when the Earth warms.
  17. How we know global warming is still happening
    WeatherRusty, the duplication of your entries is due to your browser (or the server?) retaining the code for posting your comment, even after the page has reloaded to show your comment. When you reload that page by clicking your browser's reload button, that same code for posting gets sent again. It's happened to me multiple times (sorry, everybody). You might get an alert box after you click the reload button, warning that the browser will "repost" or somesuch phrasing. If you see that, click the Cancel button in that alert box. To avoid all the above, I suggest that after you post, you go to any other page, which will force the posting code to be flushed.
  18. How we know global warming is still happening
    I have no idea why my posts are in duplicate, I hit submit only once. RSVP, "1 degree divided by 300 K = .003333" 288 K is the average surface temperature of Earth and nearly all of that is due to radiation received from the Sun including 33 K amplification due to the greenhouse effect. "0.3% is in the noise, and is due to many factors." The "noise" is not random...it is forced and the job of science is to quantify the forcing. The ~1 K increase is part of a long term trend forced by 1.6W/meter^2 increase in radiative forcing, much of which is being absorbed by the oceans.
  19. How we know global warming is still happening
    RSVP, your water jug analogy is incorrect. The aerosols increasing and decreasing due to a volcano are instead the equivalent of a valve decreasing and increasing the flow of water into the jug. CO2 increasing is like moss growing in the hole at the bottom of the jug, reducing the flow of water out of the jug.
  20. There is no consensus
    Chris, ...RE your post 157 above, ( the Oerlemans paper ), the abstract you posted did not tell me much. So I did some research on the data and as far as I can see, glaciers have been generally melting and receding since about 1850, which is well before massive amounts of man-made CO2 were pumped into the air. Also, the IPCC models only require CO2 input after say 1970. According to the IPCC graphs, before 1970, natural variations can explain most of the temperature increase. Now since 1970, I agree, that glaciers have been generally receding, although in several areas they have actually been advancing. But the important points to note are that : 1) Glaciers started to recede well before 1970 and so the receding of glaciers after 1970 was to be expected simply based on historical ( natural )trends. 2)There has been little or no incresae in the rate of glacial recession since 1970. Thus there is little evidence here for me to conclude that recent man-made CO2 emissions are responsible for glacial retreat. If we look at one hypothetical glacier, is it not true that if precipitation of snow at the higher, source of the glacier decreases then there will be less weight forcing the glacier down the valley. Thus the rate of advance of the glacier can be affected by other factors besides warming.
  21. How we know global warming is still happening
    WeatherRusty said What you view as fanaticism derives from a strong confidence in well established physical principles as they are applied to the issue of climate change. ------------------------------- What I view as fanaticism is OVER confidence in theories that are based on well established principles. 1 degree divided by 300 K = .003333 0.3% is in the noise, and is due to many factors.
  22. How we know global warming is still happening
    Philippe Chantreau at 17:40 PM on 4 October, 2009 RSVP, "a closed system called Earth." Do you really mean that? --------------------------------- The expression is appropriate given that we are considering the Earth as a whole and a discussion that presupposes no changes in solar activity (which of course is not true).
  23. How we know global warming is still happening
    Tom Dayton answers my earlier question, "what brought the temperature back up to "normal" after the Krakatoa eruption." The answer unfortunately is not consistent with the radiation budget of greenhouse models that imply that without a net surplus of radiative energy (as in the case of extra CO2 in the atmosphere) average temperatures should remain at steady state. The model is oversimplied of course, which is the whole point of the question. An analogy may help visualize things. Assume you have a 5 gallon jug vessel containing 3 gallons of water. Water is dripping into the jug from a faucet at the same rate being lost through a hole at the bottom of the vessel, (assume no evaporation). Under these conditions, the level remains at 3 gallons forever, until one day, 1 gallon is removed. All things being equal in terms of flow rates, the level then stays at 2 gallons. There is no reason for the level to return to 3 gallons. At least I have not given one. Likewise, the greenhouse global warming theory assume equilibrium that is disrupted by CO2 levels rising. Without this happening, the Earths average temperatures would remain exactly where they are forever. And applying this same simple incomplete model to the situation after the Earths temperature drops from a volcanic explosion, it should remain low forever as well. You did not explain where the extra energy comes from to get the temperature back to "normal", nor did you explain why it should stop rising when it gets to "normal".
  24. Philippe Chantreau at 17:40 PM on 4 October 2009
    How we know global warming is still happening
    RSVP, "a closed system called Earth." Do you really mean that?
  25. How we know global warming is happening, Part 2
    shawnhet why do you average the heat absorbed by the ocean over the whole earth?
  26. How we know global warming is happening, Part 2
    Thanks for that Chris, I concur that the warming for that period seems to be more like 0.6Wm-2 rather than the 0.82 number mentioned above by John Cook. I just wanted to make sure I was reading it right. Cheers, :)
  27. How we know global warming is happening, Part 2
    BTW..how much of the increase in ocean heat content is due to vulcanism?
  28. How we know global warming is still happening
    RSVP said: "Socrates said, I know I know nothing. (You can even argue about what he really said). My understanding of this statement is that you cant really know anything for sure. I find the spirit of this discussion poisoned by fanaticism, as opposed to skepticism." Science is a logical methodology employed to aid in our understanding of the world. It works rather well, we have learned a great deal of how the world works even if that knowledge is incomplete. We understand quite well the physics as to how material objects are warmed and cool. The Earth is just a body floating in space and warms and cools based on the same physics as any other body. Scientists have much of this figured out. It is not like we know very little, to the contrary what we know is demonstrably the essence of what is responsible for the warming and cooling of Earth. What we don't know very well are some of the details, but the big picture is rather clear. The Earth is warming as a matter of empirical observation and the basic physics as to why that is occurring are well established. This gives us a logic basis for an expectation for a continuation of that warming and an estimation of what that warming will be, allowing for the uncertainty inherent to the less well understood details. What you view as fanaticism derives from a strong confidence in well established physical principles as they are applied to the issue of climate change.
  29. How we know global warming is still happening
    RSVP said: "Socrates said, I know I know nothing. (You can even argue about what he really said). My understanding of this statement is that you cant really know anything for sure. I find the spirit of this discussion poisoned by fanaticism, as opposed to skepticism." Science is a logical methodology employed to aid in our understanding of the world. It works rather well, we have learned a great deal of how the world works even if that knowledge is incomplete. We understand quite well the physics as to how material objects are warmed and cool. The Earth is just a body floating in space and warms and cools based on the same physics as any other body. Scientists have much of this figured out. It is not like we know very little, to the contrary what we know is demonstrably the essence of what is responsible for the warming and cooling of Earth. What we don't know very well are some of the details, but the big picture is rather clear. The Earth is warming as a matter of empirical observation and the basic physics as to why that is occurring are well established. This gives us a logic basis for an expectation for a continuation of that warming and an estimation of what that warming will be, allowing for the uncertainty inherent to the less well understood details. What you view as fanaticism derives from a strong confidence in well established physical principles as they are applied to the issue of climate change.
  30. How we know global warming is happening, Part 2
    We should also bear in mind that each component of the system responds to change differently, according to its' physical characteristics. The oceans represent an enormous buffer as they absorb and emit heat more slowly than the land or atmosphere. It seems to me that we should not expect an immediate correlation between atmospheric cooling and ocean cooling. There will be a time delay. Presently SST data suggests a diminution or even cessation in the warming trend dating from around 2003 which should eventually be reflected in the data for ocean temps. I'm not aware of any direct comparison available for both sets of data...Chris..any suggestions?
  31. How we know global warming is still happening
    RSVP asked what brought the temperature back up to "normal" after the Krakatoa eruption. Answer: The falling out of the atmosphere, of the solar-radiation-reflecting aerosols that the volcano had thrown into the atmosphere. Technically, it's not simply a matter of gravity causing the aerosols to fall out; that is one contributor, but other processes also contribute to the rapid removal of those aerosols. See the page It's volcanoes (or lack thereof) here on the Skeptical Science site for more info. That page contains references to peer-reviewed scientific publications from which you can get all the details you care to see. Or you can go to the US Geological Survey's site, because studying volcanoes is one of their primary jobs. They even have a page titled Volcanoes and Global Cooling. Even more detail is at the USGS page Volcanic Sulfer Aerosols Affect Climate and the Earth's Ozone Layer.
  32. How we know global warming is still happening
    Steve L wrote... "Wind doesn't concentrate heat at ground level thousands of km from global point point sources. Further, it takes more heat to melt ice than to raise air temperature, so for this and other reasons I dispute your assertion that the Arctic and alpine glaciers are the easiest places to detect global warming." It's not about what you can measure, although I can possibly understand the temptation. I was referring to a physics concept not a meteorological concept. The physics concept being that you cant destroy energy and then applying this to a closed system called Earth. The first place you might notice the effects would be in a snow line etc. The method I am using to deduce this possibility is called thinking. Independent thinking as opposed to Googling.
  33. How we know global warming is still happening
    Socrates said, I know I know nothing. (You can even argue about what he really said). My understanding of this statement is that you cant really know anything for sure. I find the spirit of this discussion poisoned by fanaticism, as opposed to skepticism. It is one thing to assert that CO2 has the effect of trapping solar energy, and quite another to conclude that it is the main cause of global warming. Why even bother to continue investigating this subject? Its a done deal. It should be a crime to burn fossil fuels. I suppose that is coming. If not, for sure the price of oil will be going up, and the question of who is thriving on it will be a little more clear. To answer WeatherRusty The major ice ages precede recorded history, but there have been periods of strong cooling in recent times. http://www.drgeorgepc.com/Volcano1883Krakatoa.html Here is an abstact from this article. ---------------------------------------- Upper Atmosphere Effects Ash from the eruptions was propelled to a height of 50 miles (80 kilometers) in the upper atmosphere blocking the sun and plunging the surrounding region into darkness for two and a half days. Climatic Changes It has been estimated that at least 21 cubic Km (appr. 11 cubic mile) was ejected from the eruption of Krakatoa and that at least 1 cubic mile of the finer material was blown to a height of about 17 miles (27 Km). The volcanic dust blown into the upper atmosphere was carried several times around the earth by air currents. This volcanic dust veil not only created the spectacular atmospheric effects described previously but acted also as a solar radiation filter, reducing the amount of sunlight reaching the surface of the earth. In the year following the eruption, global temperatures were lowered by as much as 1.2 degree Centigrade on the average. Weather patterns continued to be chaotic for years and there were major climatological changes which affected the entire globe. Temperatures did not return to normal until five years later, in 1888. ------------------------------------- Whether this was an ice age or not, my question remains. After this cooling, what brought the temperature back to "normal"? This is not directed to anyone in particular, especially readers who only believe a thing is true if it can be answered by a Google search. Preferably a person who can think independently. What brought the temperature back to "normal"?
  34. How we know global warming is still happening
    A real glass greenhouse interior is warmed more by the suppression of convection between the interior and exterior by the glass barrier than by absorption of IR by the glass. The tropopause between the troposphere and stratosphere is a barrier to convection also due to a temperature inversion. Nearly all energy leaving the troposphere and most leaving the glass of a greenhouse is in the form of radiation. This is why the forcing for a doubling of CO2 (3.7W/m^2) is measured from the tropopause I believe. When have volcanic eruptions sent the Earth into Ice Ages?
  35. How we know global warming is still happening
    A real glass greenhouse interior is warmed more by the suppression of convection between the interior and exterior by the glass barrier than by absorption of IR by the glass. The tropopause between the troposphere and stratosphere is a barrier to convection also due to a temperature inversion. Nearly all energy leaving the troposphere and most leaving the glass of a greenhouse is in the form of radiation. This is why the forcing for a doubling of CO2 (3.7W/m^2) is measured from the tropopause I believe. When have volcanic eruptions sent the Earth into Ice Ages?
  36. How we know global warming is still happening
    Well, I guess what's appropriate depends to some degree on what the topic of the post is and whether or not anybody is relying on a particular bit of misinformation (eg from a misnomer) to support an argument. You're not going to get rid of the name -- too much history, etc, and I don't think anybody here gets confused by it (who is thriving upon it?). But, whatever, it was just a PS. Your response regarding your nonsense is also worthy only of a PS. Wind doesn't concentrate heat at ground level thousands of km from global point point sources. Further, it takes more heat to melt ice than to raise air temperature, so for this and other reasons I dispute your assertion that the Arctic and alpine glaciers are the easiest places to detect global warming. Finally, on to your question. Don't worry, this time I didn't get loost. Response 1: That's your question? Then what about all that other stuff about "inhospitable to life". I was going to refer you to PETM. Response 2: What don't you like about any of the internet resources already available that explain the end of ice ages? Check out "ice ages" or "Milankovitch" on Wikipedia. Response 3: Google didn't find much with "delicate sunlight balance theory".
  37. How we know global warming is still happening
    RSVP asked "What caused ice ages to end?" Orbital mechanics (a.k.a. Milankovitch cycles) followed by feedbacks such as greenhouse gases and ice and snow. At the top left of this page, click the link "Climate's Changed Before." Also see the section titled Milankovitch cycles (finally) explained on this page of cce's "The Global Warming Debate" site.
  38. How we know global warming is happening, Part 2
    Shawnhet, I think your analysis applies to an imaginary circumstance where only the oceans absorb heat under the influence of positive radiative imbalance. But additional heat is absorbed by the land, atmosphere, and in melting ice. According to Hansen et al (2005), this amounts to around 0.05 W.m-2 globally averaged. So the globally-averaged heat uptake is of the order of 0.6 W.m-2 during 2003-2008 (according to the analysis of Schuckmann, 2009). If we’re comparing this value with the value estimated by Hansen et al (2005) for example (0.85 W.m-2 in 2003), we should probably consider the fact that the sun was radiating energy at around 1 W.m-2 more (top of solar cycle) than in 2008/9 (smack bottom of solar cycle). If we consider the effect on absorbed solar radiation at the surface, this amounts to a (temporary!) reduction near 0.175 W.m-2 (1 x 0.25 spherical geometry x 0.7 albedo) now, compared to 2003. So we should probably be comparing 0.6 W.m-2 to something quite a bit less than 0.85 W.m-2 (something around 0.75 W.m-2 perhaps). So the heat uptake data determined by Schuckmann 2009 is of a similar order to that determined by Hansen et al 5 years ago. It is somewhat lower than the value determined by Trenberth (2009); however there must be significant uncertainty in these values. The main point is that current data is increasingly at odds with the notion (see blogosphere ad nauseum!) that the oceans are cooling. They’re not. The evidence supports the rather straightforward expectation that a positive radiative imbalance results in absorption of heat and global warming.
  39. How we know global warming is still happening
    To Steve L. For one thing, I dont think it is so inappropriate to point out that the term GREENHOUSE is misnomer. The point here, is that the term was chosen based on a hypothesis, not a theory. If the hypothosis turns out to be in error, keeping the name around only creates more confusion, which apparently is what many people appear to be thiving on. As far my nonsense. I was saying that energy pollution from an automobile for instance is cummulative in a global sense, and if not lost into outer space spreads out wherever the wind takes it. The edges of glaciers and ice caps are the easiest places to observe the effects of global warming. And for the third time my question. The question is simple. What caused ice ages to end? If the Earth maintains a delicate equilibrium as per the CO2 greenhouse model, why in the absense of fossil fuel burning did the temperature of the Earth rise? And why did it stop rising? or did it stop? I hope I did not loose you this time.
  40. How we know global warming is still happening
    Just visiting briefly today -- rsvp, I don't really understand what you're asking. I half gave up on trying to understand you when you replied to my question in 14 with a bunch of nonsense about people carrying the energy all around the world such that the Arctic is the first place we should notice warming. But with the all caps and exclamation marks, it seems very important for you to get an answer to your question. Try laying out your reasoning and asking the question again. PS. I agree with Tom that you should do more reading. Right now you're diluting potentially interesting questions (we'll see) with junk about greenhouses being inadequate analogies for the enhanced greenhouse effect (which is old, well-known, and irrelevant).
  41. How we know global warming is still happening
    ANYONE can say, "hold your question until youve read all that material" to ANY QUESTION. That is a copout! ANSWER THE QUESTION! By the way, in a GREENHOUSE, light is REFLECTED BACK into the chamber. CO2 ABSORBS IR! It CONVECTS energy into the surrounding mass of air around it. Thus the observation that it would saturate. And if it happens to re-radiate, the radiation is isotropic unlike the surface of glass in greenhouse which points the light downward. Now please use the delicate balance theory to explain how the Earth comes out of an Ice Age, without skirting the question::::
  42. How we know global warming is happening, Part 2
    There is a potted history of the(apparent) ocean cooling found in 2007 here: http://earthobservatory.nasa.gov/Features/OceanCooling/ It seems there was bad data from the XBT floats and theArgo floats, one giving consistently high results the other consistently low. Cross checking with ERBES data ( which are not consistent with CERES) and correcting the float data gave a very different picture of ocean heat content. Also there is extensive info on Argo float position and coverage etc plus data at: http://wo.jcommops.org/cgi-bin/WebObjects/Argo.woa/wa/
  43. How we know global warming is still happening
    RSVP: You have not read those sites carefully enough. The experts do agree with each other. And the other issues you just now raised are dealt with in those sites, as well as here on the Skeptical Science site. (Click on "View All Arguments" at the bottom of the thermometer at the top left of this page.) You need to read those sites. All the way through. It won't take long, even if you read thoroughly. Hold your questions until you've read all that material.
  44. How we know global warming is still happening
    Revising wording from above... ...it should be a no brainer to explain how exactly the Earth comes out of an ice age, and what keeps it from warming to a point so hot that it becomes inhospitable to life???? Please use delicate sunlight balance theory.
  45. How we know global warming is still happening
    To Tom Dayton... I have gone to the sites you posted and these bring a lot to the table. Almost too much, in that there is an overriding sense when reading it that even the experts cant agree with each other. For instance, the bit on whether IR absorption saturates, and inacceptance of extensive and laborious computer modeling, etc. At any rate, what I find all this quibbling really points to is that the effect of CO2 on global warming is not violent in the way volcanic eruptions have plunged the Earth into ice ages. In fact, with all the endemic global warming you can imagine from CO2, the effects of a single volcanic eruption could leave us all freezing and starving to death from lack of vegetation within a growing season. Given the theory that average temperatures depend on such a fragile balance of the sunlight's heat, (and with so many experts abounding), it should be a no brainer to explain how exactly the Earth comes out of an ice age without going past a point so hot that it becomes inhospitable to life???? as there seems to be hard feedback mechanisms that take the Earths temperature up from ice ages and hold it steady past this point and others that are ignored when referring to the effects of CO2. Or is CO2 in charge of everything? My last little word would be that it might make some sense that CO2 concentrations as discovered in ice core samples correlate not because CO2 drives temperatures around, but because living organisms that produce CO2 do better when things warm up.
  46. How we know global warming is happening, Part 2
    Is the 0.77Wm-2 supposed to be averaged over the whole surface of the Earth? The graph seems to be referring to oceans on their own. The graph covers 6 years which equals to 6*365.25*24*60*60 seconds = 189345600 seconds(A) Eyeballing the graph it looks as though the six year period has seen an ~1.5*10^8 Jm-2 increase.(B) Dividing B by A gives us ~0.79W-m2(pretty close to the 0.77) storage in the oceans, but the oceans are only ~70% of the Earth's surface. This gives us 0.56Wm-2 averaged over the surface of the Earth. I wonder if we're comparing apples to oranges. Cheers, :)
  47. Some Skeptical Science housekeeping
    Yes, great work John, thank you. A small suggestion. You might watch out for sock puppets if you don't already. I have a gut feeling there may be just one denialist hiding behind several aliases here. But then I have always had a nasty suspicious mind!
  48. How we know global warming is still happening
    "Thinking of it this way also shoots down all the silliness about the 2nd law of thermodynamics that some throw in for more confusion." Absolutely...It is the surface that warms the atmosphere. Earth's average surface temperature at 288K is some 33K degrees warmer than the equilibrium black body temperature of Earth as viewed from space at 255K. The 255K emission is on average given from high in the troposphere (~16,000'), without an atmospheric greenhouse effect the 255K emission would come from the surface. The stronger the greenhouse effect the higher in the troposphere is the 255K emission. The atmosphere does not warm the surface because it is warmer than the surface (it isn't), it does so by inhibiting cooling of the surface. The loss of thermal energy continues outward toward space on average, a cooler atmosphere is not radiatively warming a warmer surface which would violate the Second Law. Sorry if this seems off topic.
  49. Philippe Chantreau at 05:40 AM on 2 October 2009
    How we know global warming is still happening
    Good reminder Weather Rusty. I think the best, shortest, clearest description was given on RC by one of the contributors: the greenhouse effect impairs the cooling of the surface. Increased GH effect means higher equilibrium temperature. It's rather simple. Thinking of it this way also shoots down all the silliness about the 2nd law of thermodynamics that some throw in for more confusion.
  50. There is no consensus
    "So from what you are saying,variations in those natural factors which affect temperature ( sun, El Nino etc )are as likely to affect cyclones, sea-level changes, polar ice-melting etc as man-made CO2 emissions?" That's not really correct. The natural factors generally result in fluctuations around a trend which under normal circumstances is flattish (on the multi-decadal timescale). In a world warming under an enhanced anthropogenic greenhouse forcing, the natural factors result in fluctuations around a rising temperature. It is the rising temperature that causes the sea level rise, ice sheet melting and so on. Of course if an El Nino occurs on a rising temperature trend, this will supplement the warming producing a short pulse of excess heat which temporarily would accelerate warming onsequences like ice sheet melting. A La Nina will provide a slight brake on these warming-induced consequences. However these don't have much long term effect since these are very short lived phenomena. It's really only changes in solar output that potentially have significant long term consequences that could compete with anthropogenic-induced warming, but analysis of long term solar output indicates that solar variations are rather small in their effects on earth surface temperature.

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