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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 111951 to 112000:

  1. There's no empirical evidence
    #147: "Why the increase in P at the surface? Gravity?" Ah, so the temperature at the surface is merely due to the weight of the atmosphere. Then it follows that gravity causes increased temperature. In classical mechanics, gravity is a force and forces can only increase temperature (a statistical measure of kinetic energy) when work is done. Yes, falling objects gain kinetic energy. So you must believe that all atmospheric gas fell from outer space to the surface of the earth? "I have formed an opinion on the matter which I have expressed here for either refutation or retention," And yet this opinion remains unsubstantiated. The quality of the replies here is excellent (and quite patient). Interestingly, I last heard the same 'I dont think so' opinion over at a competing website, W..T?
  2. There's no empirical evidence
    AWoL, only the action of increasing pressure of a given quantity of gas increases the temperature. Once the gas is at that new pressure, the temperature does not increase any more. Pump up a bicycle tube quickly and you can feel the tube get warmer from the air being compressed from one atmosphere (outside the tube and pump) to greater than that (inside the tube). But let the tube sit undisturbed for awhile and it (and the compressed air inside it) will exchange energy with the surrounding air until the tube once again is at the same temperature as its surroundings. It does not continue getting hotter, nor remain hot by replacing its lost energy, merely by virtue of being at high pressure. Air in the Earth's atmosphere does get compressed when gravity drags it down, and so it does heat. But eventually that same air rises and so loses that heat it acquired. Averaged over the atmosphere, across time, the net effect on total atmospheric temperature is zero.
  3. There's no empirical evidence
    AWol, theendisfar - you might find the recent Science of Doom postings on The Hoover Incident and Heat Transfer Basics and Non-Radiative Atmospheres useful primers. They discuss what would happen if we didn't have greenhouse gases in the atmosphere.
  4. There's no empirical evidence
    Muoncounter says:- "What does gravity have to do with that?" at TOA T=0degC,P=near 0. at surface, T=15degC,P=15lbs/squ in Why the increase in P at the surface? Gravity? The "I don't think so" means that I have formed an opinion on the matter which I have expressed here for either refutation or retention, dependent on the quality of replies. For that is the raison d'etre of this website, I think.
  5. There's no empirical evidence
    #145: "Surely gravity gives rise to an increase in temp at the surface.P1/T1=P2/T2?" What does gravity have to do with that? "leave just N2 and O2. Would it make much difference? I don't think so." It would be interesting to hear you substantiate this opinion, in more depth than 'I don't think so'. Perhaps you should have a look at Dr. Roy Spenser's backyard experiment verifying that atmospheric greenhouse gas does indeed warm the surface. Talk about empirical evidence! And from a noted skeptic, no less.
  6. actually thoughtful at 05:53 AM on 23 August 2010
    The Strange Case of Albert Gore, Inconvenient Truths and a Man in a Powdered Wig
    I've found Gore very useful, if anyone brings him up, they are not focusing on the science, so I can safely ignore them.
  7. There's no empirical evidence
    Chris wrote:- "The enhanced warmth is due to the trapping of solar energy by atmospheric greenhouse gases. More energy is retained in the earth system in the presence of greenhouse gases than would be there without them (around 33 oC's worth of surface temperature)." Surely gravity gives rise to an increase in temp at the surface.P1/T1=P2/T2? Take out "greenhouse gases" and leave just N2 and O2. Would it make much difference? I don't think so.Sorry but the idea that the 33degC difference is due to 0.03-0.04%"greenhouse gases", I just don't get.....and neither does 90% of the folk I've talked to who have made an effort to understand this so-called "science".
  8. There's no empirical evidence
    theendisfar at 04:28 AM, I look at things from a different perspective. Whilst we live immediately on the surface within the atmosphere, the main sources and sinks for heat already within the system are the oceans and the land. H2O in it's various forms plays the primary role in trying to constantly maintain thermal equilibrium because all sources and sinks are not equal. This is what we know as weather. Solar radiation is the primary source of heat and before it can heat the atmosphere it must first intersect the planets immediate surface before it undergoes any transformation. For this reason I believe that any changes begins with any variations on the amount of solar radiation that intersects with the earths surface. The output of the sun may vary, or conditions in the atmosphere between the sun and the surface may vary causing changes in the amount of solar energy that arrives, and where it arrives. Clouds are what I believe to be the major factor that drives that. The main problems with making a case for clouds is that there is little historical data available, and the understanding of the processes involved in the formation of clouds is low. This makes such discussions difficult, CO2 is a much simpler concept for the average punter to grasp, as you mentioned the thinking has already been done by others, so clouds are mostly consigned to the too hard basket.
  9. There's no empirical evidence
    theendisfar, if more money goes into your bank account than goes out of it, then money accumulates in your bank account. Whether that money is distributed across your checking, saving, and money market subaccounts within that bank account is irrelevant to the fact that the total bank account amount increases. Do you agree with that?
  10. There's no empirical evidence
    theendisfar at 03:48 AM on 23 August, 2010 ”Energy is never actually trapped anywhere” Of course it is. Obviously one needs to be specific about what one means in any particular case. However it’s a dull “argument” that attempts to negate truism by semantic quibbling. The fact that the earth has a biosphere that is conducive to higher lifeforms, not to mention our entire way of life, is due to trapping energy; e.g.: - the energy of solar photons of visible wavelengths/energies is trapped in photosynthetic reactions, converted to free energy in ion gradients across cell membranes, and chemical bond energies in the form of (initially) generic carbohydrate (CH2O)n. It’s the trapping of solar energy that drives life processes. - Our societies are largely fuelled by the trapped energies of solar photons, sequestered for eons in the form of chemical energy, and released by controlled oxidation. - Our earth is around 33 oC warmer that it would be as a blackbody emitter with an earth-like albedo bathed in the solar flux in the absence of an atmosphere. The enhanced warmth is due to the trapping of solar energy by atmospheric greenhouse gases. More energy is retained in the earth system in the presence of greenhouse gases than would be there without them (around 33 oC's worth of surface temperature). Call it something else if you like but you can't negate a reality with semantic "arguments"! It’s obvious what “trapped energy” means in these real world contexts.
  11. There's no empirical evidence
    Tom, The answer cannot be answered so simply because we do not agree. I can use simple terms, but the farther we are from having the same understanding, the more simple steps will have to be described. #139 has given me a better understanding of your understanding, so after I go out and enjoy some of this beautiful day, I will try to bring our understandings together from my end. Thanks for doing the same from your side. The distribution of that energy, and even its form (e.g., sensible heat versus latent heat) is irrelevant to that accumulation that results from that imbalance of in versus out. Do you agree with that? Not a chance, and I believe that I can accurately describe my position, but later :)
  12. There's no empirical evidence
    johnd, Glad someone is :) It frustrating as heck debating people who only rely on and offer other people's work, but can't find any flaws with your understanding. If they can't refute plain English how can I reliably think they have any understanding of the works they're offering? So it goes, I suppose. Just looking for a clarification, when TOA is being discussed, what point in the atmosphere is actually being considered the TOA? Beats me, but I will offer it plays little role in surface or even tropospheric temps with regards to any radiation that is 'trapped' in the system. As long as it is outside the Stratosphere, that is. Why/how would it? Curious, did you get a chance to ponder 107-110?
  13. There's no empirical evidence
    theendisfar, you wrote "You must understand that the journey of the energy within the system is just as important as to how much is incoming and how much s outgoing." You're not addressing my simple, direct question. The journey of the energy within the system is irrelevant to the bottom line of how much energy is coming in to the entire Earth system (atmosphere, land, ocean) as radiation from the Sun, minus how much energy is going out of that same system as radiation to outer space. Empirical evidence summarized at the top of this page tells us that the "in" energy is greater than the "out" energy. The unavoidable consequence is that energy accumulates inside the system. The distribution of that energy, and even its form (e.g., sensible heat versus latent heat) is irrelevant to that accumulation that results from that imbalance of in versus out. Do you agree with that? Simple question.
  14. There's no empirical evidence
    KR, That is what you're saying in that post! Absolutely not! What I'm saying is that the link you provided was an abstract that didn't even attempt to hide that it was a bunch of number crunching. Had I sent a similar link to you, I would have expected you, a skeptic of my position, to first note all the subjective terms and data massaging. Perhaps you would not have objected to such obvious areas of question, and instead you would have objected to the source's organizational affiliations, or font, or hair color or something. Beats me. But I don't need to rely on someone else's understanding when I have one myself. One that has not been falsified. Surprising given all the 'experts' here. What you sent me was not complicated, it didn't actually state anything once you added up all the estimates, computations, constraints, adjusted estimates, revised estimates, and modest changes. That's how AGW is most often explained. I say most often just to keep the possibility that someone can actually explain it in a way that a learned skeptical person could test themselves. Seriously, if I had sent you an abstract that had all that in the heading, you would not have laughed and said nice try buddy? Simply amazing. The fact that not one person here can refute my understanding is quite telling. Nice try gentlemen, but sorry; revising estimates, then adjusting them, adding constraints, and making modest changes + "AGW is real" ain't gonna cut it.
  15. There's no empirical evidence
    theendisfar at 03:48 AM, I enjoy following this exchange. It provides an exercise in lateral thinking which is probably lost on those who only think logically, which the inhabitants here predominately do. Just looking for a clarification, when TOA is being discussed, what point in the atmosphere is actually being considered the TOA?
  16. There's no empirical evidence
    The Global Energy budgets are worse than bunkum because, 1) - The viewpoint used in IR budgets is simply wrong for what they try to depict and describe. At best the viewpoint used is misleading, but more likely the view is partial and inaccurate, being an instant and 2D view of a 24 hour and 3D planet. 2) - They completely misrepresent the real heat movements, depicting a ludicrous and physically impossible scene where radiation losses and movements dominate conduction, convection, and latent heat movements within the atmosphere. 3) - They hide / misrepresent the individual and comparative sizes (volumes) of the various energy flows. 4) - They do not take into account the temperature and the effects of the relative temperature differences of the energy flows. An agreed model of the atmosphere has to be arrived at for any meaningful debate to take place.If not agreed there will be nothing but endless nit-picking and confusion of units.All are agreed on units of time and the Earth's divisions and the location of 0deg Longitude.Something the same has to be done with respect to providing the layman with a reasonable working model of the Earth's atmosphere.The whole subject lacks definition.
  17. There's no empirical evidence
    Tom, the energy trapped in the atmosphere by GHGs ends up in the form of heat, by those GHG molecules banging into other molecules. Energy is never actually trapped anywhere. We disagree on how the energy at the surface it transfered to the atmosphere. You say radiation being absorbed by GHG and then collisions with N2 and O2 molecules, I say via conduction at the surface and slightly, very slightly, by radiation absorption and then conduction to immediate surroundings. Convection merely helps speed that distribution, not reduce that total amount of energy. Have I stated otherwise? The total heat of the system increases. I believe I see the disconnect now that I quickly looked at #134. If you'll take a detailed look at 107-110, 128, last part of 130, and last paragraph of 131 it will help prepare you for my response to #134. Please take a moment to refute 107-110. You must understand that the journey of the energy within the system is just as important as to how much is incoming and how much s outgoing. Regions of the Earth's atmosphere are different temperatures, not only because of the input and outgoing energy, but because of the Transport mediums of available for the flow of energy. Your top of atmosphere reasoning (radiation only means of escape) has no explanation as to why the Troposphere averages 15 C at the surface and -54 C at the Tropopause (which is highly variable, altitude, from equator to poles).
  18. What caused early 20th Century warming?
    Marcus at 20:49 PM, if you are claiming that the cloud chart is dubious, please backup such opinion by providing data that invalidates that depicted in the chart. It is up to you to provide any longer term data available if you feel the period covered is cherrypicking. Lets see what you have in real data. It is well established that the variable and irregular cycle of warming and cooling of surface ocean waters determine how events such as El-Nino/La-Nina and the IOD, as well as other similar events in other oceans, are formed. There are only two sources from where variations in SST can originate, those being the circulation of heat within the oceans, or the solar energy being absorbed at the surface. Given it is accepted that the heat content of the oceans is increasing, then that obviously begins with increasing the SST. Irrespective of whether you accept the data of the cloud chart or not, what is not in dispute is that clouds provide approximately 2/3 total coverage and that coverage is irregular and follows certain patterns over both the short term and longer term as evidenced by the cycles of droughts. It has been established that the USA dust bowl era was due to a combinatiion of SST in the Atlantic and the Pacific that altered the atmospheric circulation across that portion of America. Only time will tell if that was a random event or part of a cycle that may reappear in the not too distant future.
  19. Weather vs Climate: Watch the waves, miss the turning of the tides
    #3: "Three decades is far from long enough in determining either weather or climate trends" OK, so look at a longer time span: This was made from a recent GISSTemp release going back to 1880. The plateaus represent each time a new high or low (in the temperature anomaly) is set. Hot summers (JJA average) continue getting hotter, but summertime lows don't get any lower; winter (DJF average) record lows don't get any lower than the -0.62 deg C anomaly from 1893.
  20. There's no empirical evidence
    theendisfar, you agreed that: 1. The Sun is the only input of energy to the Earth system (combined atmosphere, land, ocean). 2. CO2 traps some of that input energy. 3. Radiation is the only way for that input energy to escape the Earth system (combined atmosphere, land, ocean). Then surely you must agree that the total energy in the Earth system (combined atmosphere, land, ocean) increases as a result of the CO2 trapping energy. I'm talking about the total, regardless of where or how it is distributed within that system. Do you agree? Please give a simple, short, answer directly to that specific question.
    Moderator Response: Empirical evidence of point 2 is in the post at the top of this page, in the section "CO2 Traps Heat." Empirical evidence for the conclusion is in the section "The Planet is Accumulating Heat."
  21. There's no empirical evidence
    theendisfar - You object to Trenberths measurements because they're complicated? That is what you're saying in that post! Imagine the following conversation about some science conclusion: "How did you measure your data for X?" "I used a mass spectrometer." "Ooo - that's complicated. And that opens more questions than it answers!" "Then I suggest you try disproving mass spectroscopy - good luck, come back when you have something valid to say." The various uncertainties in the Trenberth energy budget measures are on the scale of the total convective energy exchange - it's that small a portion of the energies (~18-20W/m^2, listed as "sensible heat"). IR from the ground (and back IR from the atmosphere) was first clearly measured in the 1950's, and has been repeatedly measured since then with a variety of instruments: ~396W/m^2. So: when you've disproved FTIR and pyrometers, and come up with different estimates for global precipitation and energy of vaporization of water - then we can talk about your new (and measured) energy budget. Insisting, in the face of actual measurements, that your personal world view is overridingly true (in this case that convection is the major portion of energy exchange) is a Common Sense logical error. It reflects a lack of domain specific experience.
  22. Can't We At Least Agree That There Is No Consensus?
    poptech wrote : "No author has asked to have their papers removed. Pielke Jr. never did, Brooks never did, no one." Once again, I have to repeat what has already been repeated many times before, but which you still can't seem to understand : A quick count shows that they have 21 papers on the list by me and/or my father. Assuming that these are Hypothesis 1 type bloggers they'd better change that to 429 papers, as their list doesn't represent what they think it does. Roger Pielke Jr's Blog - Better recheck that list Of course, Poptech told Pielke what was skeptical about those papers and Pielke Jnr agreed and thanked Poptech for pointing out what his own papers were actually about. Actually, he didn't - he just ignored Poptech subsequently (probably a good strategy), and I suppose that speaks volumes about how he viewed his papers being abused in that way. To be more exact, Pielke Jnr showed Poptech where he could find proper scepticism, not made-up skepticism : "And if you want a good set of citations against certain "alarmist" conclusions (whatever you mean by that) I'd suggest the IPCC."
  23. Weather vs Climate: Watch the waves, miss the turning of the tides
    You've immediately confused the issue. Firstly you correctly state that to determine trends in climate, the changes in weather needs to be looked at over a long time span, then immediately provide a graph that uses the last 3 decades to support it. Three decades is far from long enough in determining either weather or climate trends when weather cycles have been identified where the rise and fall of the tides in a manner of speaking, takes 6 or 7 decades to complete both phases, in and out as it were, and reconstruction of El-Nino events indicate that perhaps any changes in the "tidal" frequency of them needs to be considered in terms of centuries. However, identifying any trends will always be the easy part, understanding what any trends and cycles mean and why they occur is the hard part. The tide analogy gives opportunity to consider whether the forces that drive the tides that affect even very small bodies of water, has what affect on the moisture suspended in the atmosphere?
  24. There's no empirical evidence
    Theendisfar, the energy trapped in the atmosphere by GHGs ends up in the form of heat, by those GHG molecules banging into other molecules. Convection merely helps speed that distribution, not reduce that total amount of energy. The total heat of the system increases.
  25. There's no empirical evidence
    KR, Clarification. This is relevant because if what I have stated is accurate, cannot be falsified, then one of the understandings must be wrong. 'Understandings' meaning, energy can be added to a system by slowing, trapping, what have you, the radiation rate through whatever mechanism you like, GHE, enhanced GHE, super enhanced, etc versus the 1st and 2nd Laws are kept intact. The Sun is the only source of energy that adds energy to the Earth's system. Well, Star light (entire spectrum) does too if you want to get picky. This is why I brought up the back pressure that would occur if you slowed the rate of cooling by reducing the radiation rate (speed of light) and instead had to use Convection, several dozen meters per second max. The 2nd Law clearly shows that if you reduce the rate of one means of energy transfer, it will automatically increase the rate of another means if available. Again, for clarification, convection only moves the energy to the top of the Troposphere where radiation becomes the only means to transfer energy and it again reaches the speed of light. What I'm saying is that the atmosphere itself can easily absorb the extra 2 Watts from CO2 trapping via increased convection rate and by the elasticity of the atmosphere itself. The altitude of the troposphere is much higher at the equator than the poles far a reason.
  26. Dust-Up On Mars: Should Martians Be Sceptical of Global Warming?
    First, Mars has no water, no tectonics plates and no magnetosphere or ozone layer. This means that you can hardly extrapolate observation of Mars to Earth. Also, the Mars Milankovitch cycle is rather different than teh Earth one. http://www.ifa.hawaii.edu/~norb1/Papers/2008-milank.pdf
  27. What caused early 20th Century warming?
    #30: "what TSI produced an equilibrium temperature of the Earth system in pre-industrial times with no other external forcings" I'm not sure what you mean. Why require 'no other externals?' Although volcanic cooling, as you suggest, is short-lived (even Pinatubo was only a 2-3 year event). And I am not aware of the significance of an 'equilibrium pre-industrial temperature'. The TSI data I've looked at (for example) show a short-term oscillation, which matches sunspot numbers reasonably well, modulated by long term signals (also present in sunspot numbers). For example, there were deep sunspot lows in the early 19th and again in the early 20th centuries. To the extent that surface temps follow these long term signal, do we not say 'its the sun?' However, when surface temps diverge from the solar signal, should we not look for the cause? What cause are you proposing?
  28. Weather vs Climate: Watch the waves, miss the turning of the tides
    Are those highs and lows for stations worldwide? In the US only? The graphic has a map of the US as its background ... Might be helpful to include a link to the source of the graphic.
    Response: It is US only. The paper it comes from is Meehle 2009. It's referenced in the intermediate rebuttal - we're still mulling over how much detail to include in the basic version - whether to include references or just link to the intermediate version for all the nitty gritty details.
  29. Is the sun causing global warming?
    The Ville You seem to be determined to find some excuse for disbarring Kirby's science. None of them valid.
  30. There's no empirical evidence
    KR, So it's not so much gibberish in that it can't be clarified, it was gibberish because of a lack of understanding and trust of the source. This is relevant because if what I have stated is accurate, cannot be falsified, then one of the understandings must be wrong. Barring someone able to falsify the understanding I have, I hold it to be accurate. And of course it has zero effect at the top of the atmosphere, where radiation is the only energy exchange with space. This is good, we agree. Convection stops at the Tropopause. Where the Earth was able to cool via Conduction, Convection, and Radiation starting at the surface, it lost Conduction with only a small amount of altitude, and then it loses Convection at the Tropopause. A transfer of energy means that energy has traveled over distance. To say that conduction plays no or little part in cooling the Earth's surface because Radiation is the only ultimate escape is nonsense. To say the same of Convection is equally nonsense. I took a look at Trenberth et al, is this what you're getting your info from? Imagine for a moment I had "provided a review of past estimates", and "performed a number of radiative computations", and "values constrained by", and ""but adjusted to an estimated imbalance", and "Revised estimates", and "radiation is adjusted", and "by making modest changes" in the short understanding I posted above. It opens far more questions than it would have answered. Again, just because convection only moves energy to the Tropopause does not mean it is not the primary transport of energy from the surface to it. Just because Conduction only moves energy from the surface to the immediate atmosphere above it, does not mean it is not the primary transport of energy to it. Any issues with #129? Make sense?
  31. University of Western Australia Open Day 2010
    I wish that some Universities in the US would create a similar program.
  32. The main culprit in mid-century cooling
    #4: very good point regarding China. From the late 90's to around 2005, the industrialized southern part of China (Shenzhen, etc) was covered in a dense haze, caused by emissions. Airborne dust and particles made it very uncomfortable to be outside. This has cleared up a lot over the past few years since around 2006. It is very possible that the Asian "brown cloud" helped mask the temperature increase on the early 00's, then, as it improved towards the end of the decade, temps started climbing faster again.
  33. Weather vs Climate: Watch the waves, miss the turning of the tides
    Now that's a great analogy. I'll definetly use this one.
  34. What caused early 20th Century warming?
    Ken #30 Alternatively you can estimate the effects of different forcing components by looking at linear models of the forcing components at different points in time. (Un)surprisingly we find that CO2 has been the main forcing component for the last 40-odd years, while the solar component was dominant previously. We also know that major volcanic forcings only last very short periods of time. So all this stuff can be estimated without estimating this 'equilibrium TSI'.
  35. What caused early 20th Century warming?
    muoncounter #28 Tell us what TSI produced an equilibrium temperature of the Earth system in pre-industrial times with no other external forcings (eg; volcanic cooling). With a fix on that 'equilibrium TSI' you can then estimate what excess Solar forcing has occurred over the 20th century and the total energy added to the system.
  36. What were climate scientists predicting in the 1970s?
    A tiny mathematical correction; Marcus's 100 ppm rise above a preindustrial level of 280 ppm would be a 36% increase, not 27%. And since current levels are actually around 392 ppm, it's really a 40% increase in CO2 (and rising every year).
  37. The Past and Future of the Greenland Ice Sheet
    Peter Hogarth wrote: I dont think Ned has suggested that current ice loss is greater than anything seen in the early holocene... and Berényi Péter replied: According to Figure 1 in the article current rate of ice loss is 26000 km3/century. That's three times faster than average rate of loss in any millennium in the last ten thousand years. So yes, he did suggest such a thing. Figure 1 shows the change in mass balance of the Greenland ice sheet over the past decade, as measured by GRACE. If Berényi Péter wants to claim that this rate of change is greater than the maximum decadal-scale rate of change during the early Holocene, that's his claim, not mine. I don't think that citing millennial-scale averages would be a good way to justify that claim. I spent a fair bit of time working on the phrasing of that post, to ensure that I didn't make any claims for which there was not clear evidence. Probably the most important point from that post is that the Greenland ice sheet was quite a bit smaller during previous interglacials. Since the projected 21st-century global mean temperature increase of 3C implies an Arctic warming of more than 3C, this is reason for concern. Thus, it becomes urgent to answer the question of how rapidly the Greenland ice sheet will respond to the upcoming temperature increase. As I discuss in the latter part of the post above, Pfeffer 2008 suggests that via realistic ice dynamics Greenland could contribute 16 to 54 cm as its share of a global sea level rise of 0.8 to 2 m by 2100. This also seems to fit well with Vermeer and Rahmstorf 2009. So I don't think there's any realistic way we could produce an Eemian (MIS-5e) ice sheet by 2100. But we could take a substantial step in that direction, and 0.8 to 2 m of SLR will have quite high economic costs in many regions.
  38. What were climate scientists predicting in the 1970s?
    GC, also consider this-if a mere 100ppm increase in CO2 emissions has been sufficient to raise global temperatures by +0.6 degrees C, what do you think another 300ppm to 600ppm might do to our climate? So long before we come close to running out of coal & oil, we will have been able to significantly altered our atmosphere & climate-perhaps to levels in which human civilization can no longer survive. Personally, I'd rather stop treating our planet's atmosphere like some giant laboratory-unlike the fossil fuel industry who're quite happy to use it in such a way.
  39. What were climate scientists predicting in the 1970s?
    Gallopingcamel #31, that's total *rubbish*. Pre-industrial levels of atmospheric CO2 was 280ppm, it is now above 380ppm. Even simple knowledge of mathematics should be able to tell you that this represents an anthropogenic increase of of 27% above natural levels, not 0.01% as you claim. Of course, RSVP would have us believe, wrongly, that an addition of anthropogenic heat-from industrial activity-that is less than 0.001% of the total heat received from natural sources-is sufficient to warm our planet in a way that a nearly 30% increase in IR-capturing gases can't. So who, again, is guilty of hubris?
  40. What caused early 20th Century warming?
    John D #22. Again with that cloud cover diagram. I've already pointed out how dubious that diagram is, given that its so obviously an example of CHERRY PICKING. Specifically, there is no indication if that peak on the LHS of the graph is typical or not. If its atypical, then the so-called decline in cloud cover is non-existent (if you go on cloud cover levels just a couple of years *before* the peak). When you can provide a diagram that covers a longer time-frame, then maybe I'll consider it. Fact is that, based on everything I've read, the strength & frequency of El Ninos & La Ninas is at least partly linked to the levels of atmospheric warming. Now whilst we had a warming trend of +0.06 degrees per decade from 1900-1950-driving by an upward trend in sunspot numbers, we've had a warming trend of +0.12 degrees per decade for 1950-2000 driven by....? Well, not increasing sunspot activity, that's for certain.
  41. Berényi Péter at 20:28 PM on 22 August 2010
    The Past and Future of the Greenland Ice Sheet
    #65 Peter Hogarth at 16:58 PM on 22 August, 2010 I dont think Ned has suggested that current ice loss is greater than anything seen in the early holocene... According to Figure 1 in the article current rate of ice loss is 26000 km3/century. That's three times faster than average rate of loss in any millennium in the last ten thousand years. So yes, he did suggest such a thing. In the three millennia before the beginning of the Holocene (15-12 ka ago) ice loss was faster, 20000-60000 km3/century (depending on model details), but that must have been caused by sea level rise induced breakup of ice shelves around Greenland, not local temperatures. Currently we do not have any large ice sheets melting far away from Greenland that could cause fast eustatic rise not compensated by local crustal rebound, neither have we extensive thick ice shelves around the island prone to sea level rise induced breakup. Therefore that kind of thing can not possibly occur now. Anyway, the "alarming" melt has started only ten years ago and has accelerated to its present rate in the last couple of years. Anything shorter than three decades is surely weather, not climate. Greenland (as opposed to East Antarctica) is a "wet" icesheet, not a "dry" one. Mass balance depends on precipitation to a high extent. With more open water around in the region increasing trend of snow accumulation of the last several decades should resume sooner or later. As many researchers have commented there is little sign of any known factor which will slow it down in the near future If so, tell them summer temperatures north of 80N are dwindling at an alarming rate during the last two decades. And this freezup in the high Arctic is clearly accelerating. In the meantime tell the Chinese to stop emitting untold amounts of soot in the atmosphere that's carried off right into the Arctic by prevalent winds. Soot pollution is not a necessary consequence of burning stuff. To make combustion more efficient and filtering smoke properly is not that expensive, the technology is ready, it is already done in any sane country. Best Hope for Saving Arctic Sea Ice Is Cutting Soot Emissions, Say Researchers While we are at it. Going for a ban on small diesel engines (a great source of tiny black carbon particles) and installing proper filters on large ones (including ship engines) is also a possible line of action, far more promising than the futile war on CO2.
  42. Can't We At Least Agree That There Is No Consensus?
    poptech -I REPEAT - I do not claim they are related to tobacco industry only that the journal is used for "tobacco science" style tactics. Namely, like the tobacco industry had with "Indoor and Built Environment", you have a tame journal for printing rubbish so you can claim "peer -reviewed articles" to back dubious claims. And look - you are doing it. And of course the knights of tobacco science were our friends in Heartland. If the journal was publishing anything of value to climate science, then other papers would be building on the science published there rather than demolishing it. Any sign of that happening - no. Cites to refute an article and cites in E&E dont count as "influencing science".
  43. Anne-Marie Blackburn at 19:39 PM on 22 August 2010
    The main culprit in mid-century cooling
    Hi Nigel. Yes, if you look at all the factors affecting climate change, aerosols have had a cooling effect and have therefore masked some of the warming expected from increasing levels of greenhouse gases. Some scientists have even suggested that we could inject huge quantities of sulfate aerosols into the atmosphere to keep global warming under control. Though technological and environmental issues mean that it's unlikely at the moment.
  44. The Past and Future of the Greenland Ice Sheet
    Given that increased ocean temperatures are helping to drive calving would it be reasonable to assume that once all the 'coastal' ice has broken away the rate of ice loss on Greenland (and Antarctica) should drop significantly? Or would exposed beach lead to greater melt and runoff? Have the regions of Greenland which are NOT covered by ice been seeing significant mass loss from the nearby portions of the ice sheet in recent years? From what I can tell the various 'mass balance' maps of Greenland the mass loss seems to extend well inland - presumably past any region that seawater temperatures should be impacting. I'm trying to get a handle on whether we'd expect Greenland ice loss to continue accelerating indefinitely or if there will be a slowdown once the coastal ice is gone.
  45. Dust-Up On Mars: Should Martians Be Sceptical of Global Warming?
    At least you are aware that there was a MWP. That puts you a step in front of John Cross. http://www.skepticalscience.com/medieval-warm-period.htm
  46. The Past and Future of the Greenland Ice Sheet
    Berényi Péter at 13:23 PM on 22 August, 2010 Thanks for fixing the link. I had not seen the Simpson paper, but at first glance fair to say your adapted chart is a simplification from their models? I'll digest the paper before drawing further conclusions. I dont think Ned has suggested that current ice loss is greater than anything seen in the early holocene... I think the fundamental argument is that current loss is not a transient event but a recently emerged and ongoing significant loss trend. As many researchers have commented there is little sign of any known factor which will slow it down in the near future (though I recall future shutting down of AMOC has been modelled).
  47. The Past and Future of the Greenland Ice Sheet
    BP, I'm trying to grasp how the volume of water that was on land and then moved to the ocean could cause a change in air pressure. Was this entirely due to rebound? (for that matter, I'll have to look up if rebound is actually conservative; that is to say, does what squishes down cause something to bulge up somewhere else? I find I don't really know or if I did I've forgotten...)
  48. gallopingcamel at 15:19 PM on 22 August 2010
    What were climate scientists predicting in the 1970s?
    Marcus (#26), The source of the carbon that humanity is adding to the atmosphere is fossil fuels. You talk about the last three centuries so use a bit of imagination and ask yourself how much will be left of the fossil fuel reserves in 2300 if we continue on our present course of industrialization and population growth. Long before the CO2 gets to 1,000 ppm fossil fuels will be so scarce (hence expensive) that they will be limited to special applications. We will be forced to depend on nuclear power and in particular the Thorium cycle. If we are clever enough we may even develop fusion power plants. The CO2 problem will have solved itself. Erratum from an earlier post. I said that mankind had added 0.1% to the atmospheric CO2 concentration. Mea culpa, I lost a decimal place and the correct figure is ~0.01%.
  49. Dust-Up On Mars: Should Martians Be Sceptical of Global Warming?
    Whenever I get told this one, I always ask what the temperature was on Mars during the Medieval Warming Period? Haven't had an answer yet
  50. There's no empirical evidence
    theendisfar - as in our previous conversation, I refer you to Trenberth et al 2009. The measured energy leaving the surface of the Earth run to 396 W/m^2 IR [pyrometers and FTIR spectrometers], 78 W/m^2 latent heat (evaporation) [from global precipitation and energy required to evaporate that much water], and ~24 W/m^2 convection [various estimates, but primarily what's left over]. Measured, repeatable (and frequently repeated) numbers. Unless you have measurements to the contrary, convection is 1/3 the energy of latent heat, and 1/16th the energy of IR, not the dominant effect you claim. And of course it has zero effect at the top of the atmosphere, where radiation is the only energy exchange with space. Next objection to the greenhouse effect?

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