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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 60051 to 60100:

  1. Return to the Himalayas
    muoncounter at 03:11 AM on 20 April, 2012 In a round about way you are making the argument that the glaciers are the source of fresh water. Precipitation and nothing else is the source. And you know what the IPCC says about precipitation in a warmer world. You tell me that we can't count on precipitation falling on the same areas that were dependent on glacial melt for their freshwater. (-snip-). Glacier melt snowmelt or rain may very well flow to an arid region. Just because a glacier is gone or becomes static, doesn't mean the rain and snow that falls won't continue to flow there.
    Moderator Response:

    [DB] Now you are just being argumentative. Precipitation is the source of glacial mass. In a warming world, glacial accumulation zones shrink and their ablation zones increase. Glaciers are declining in mass with much greater losses to come.

    All of this has been pointed out to you previously, but still you persist in what amounts to an agenda of stubbornness and patent refusal to learn.

    Off-topic diversions snipped.

    Just because answers and information are provided to Steve doesn't mean that he will then deign to learn from it.

  2. Global Surface Warming Since 1995
    re "The term essentially means "we can't rule out the possibility that it isn't warming." I don't think that is a very clear way of expressing what "not statistically significant warming" means in this context. I would prefer to say, "we can't rule out the possibility that the observed warming was caused by relatively short-term natural factors rather than by the long-term effects of human actions."
  3. Return to the Himalayas
    Steve Case#44: "I object..." The issue here is not seasonal melt that clearly provides fresh water. The issue is long term loss of ice mass - and that fresh water is on its way to being salt water. These concerns are stated very clearly: “Glaciers serve as a natural regulator of regional water supplies,” ... "Glacier changes, especially recent melting, can affect agriculture, drinking water supplies, hydroelectric power, transportation, tourism, coastlines, and ecological habitats." ... ... as the world’s glaciers continue to melt and shrink, over time there will be less water to sustain the communities that have come to depend on that meltwater. This seems an obvious point; what is the basis for your continued objection? "in a warmer world there will be more precipitation. " Once again, indeed. But you cannot count on that increased precipitation falling on the same areas that were dependent on glacial melt for their freshwater.
  4. Return to the Himalayas
    43, Steve, While I won't discount your experiment as uninteresting or useless, it does little to add to an understanding of the problem. In a nutshell, looking through your comments, your understanding of glaciers is insufficient and is tainted with 'real world, common sense' assumptions that are in many cases wrong or at best incomplete. If the topic interests you as much as it seems, I'd suggest that you spend an afternoon looking for (reputable) information on what glaciers are and how they work. They're a fascinating, varied and surprising area of study. It's well worth the time spent. Then, armed with a better understanding of the complex mechanics behind glaciers and their behaviors, you can revisit some of the scientific statements concerning how they will be impacted by climate change, in order to arrive at a better understanding of what those statements mean and eventually to arrive at a point where you can answer your own questions.
  5. Return to the Himalayas
    skywatcher at 10:26 AM on 18 April, 2012 You of course have a point. If the snow in the mountains varies year to year some of that variability will be reflected in the runoff. A 100% direct relationship or something less? Do natural and manmade impoundments modify the flow? How about ground water? Besides, there are lots of watersheds that don't have glaciers or very large ones and people live there. Is this "Problem" so absolutely crucial that I must change my life style? Just remember this conversation started out because LarryM wrote in Global Warming in a Nutshell that receding glaciers have consequences, such as disappearing fresh water supplies for billions of people. I object to the claim that fresh water supplies will disappear for billions of people because of receding glaciers. And once again, the IPCC tells us that in a warmer world there will be more precipitation.
    Moderator Response:

    [DB] "And once again, the IPCC tells us that in a warmer world there will be more precipitation."

    And, once again, you take an overly simplistic view of things. As was pointed out to you earlier (did you not read it?), some areas will stay the same, some will further dry and some will get even wetter.

    In the case of the Himalayas, much of the area (if not all) is projected to receive both less precipitation and to warm even more.

    Precipitation Changes:

    [Source]

    PDSI Changes:

    [Source]

  6. Return to the Himalayas
    Philippe Chantreau at 09:48 AM on 18 April, 2012 I ran two variables, all with the same volume of snow and same weather conditions. I packed snow into two identical plastic tubs and weighed them to make sure the same mass of snow was in each. One went in the freezer, the other the microwave to melt the snow. Then it went in the freezer when it was frozen out they came and went on the wall. I did the same with loosely packed or fluffy snow. Fluffy snow melted faster than the same mass of ice and packed snow melted slower. The different volume you see is that of the ice, the loosely packed fluffy snow produced a smaller volume of ice. The test ran over several days. You assert that there are no useful results from I did. What experiments have you done? What experiments have you found in the literature addressing the issue that are useful? If the moderators know of a more appropriate thread for this topic, I would appreciate their input.
  7. GISTEMP: Cool or Uncool?
    Kevin C - It would also be interesting to look at distance correlation factors per band in the RSS/UAH data, to see whether the regions not covered could be extrapolated as per the GISS data. And to see what that extrapolation might indicate. My guess would be that both would shift to higher trends if polar regions were considered as well, as opposed to left out as they are now.
  8. Models are unreliable
    Manny's argument, if it can be called one, cuts both ways. Here is an extraordinary claim: We can burn fossil fuels without regard to our impact on the global environment. Where is the extraordinary evidence that supports this extraordinary claim? Or do we just carry on with business as usual, on the sole basis of 'that's what we've always done'? Particularly when we know without question that our actions do indeed impact the environment in both directions - see ozone, smog, the Black Triangle, the Clean Air Act, Asian brown clouds, etc.
  9. Anne-Marie Blackburn at 22:32 PM on 19 April 2012
    Polar bear numbers are increasing
    John, I'm working on the intermediate rebuttal so I'll update this one once I've finished it. Not sure if this has been posted on here, but here's Steven Amstrup's view on the misreporting/misrepresentation of the recent report published by the government of Nunavut.
  10. Nimbin Hippie at 21:33 PM on 19 April 2012
    Cliff Ollier: Swimming In A Sea of Misinformation
    Getting back to Ollier's article, he says "Port Macquarie Hastings Council was recommending the enforcement of a "planned" retreat because of alleged danger from sea-level rise". Actually the Council hasn't made any recommendation at all. The consultant engineers' report is still on exhibition, and it is about beach and dune erosion. Sea-level rise is only mentioned as another factor which may or may not make erosion worse. The Port Macquarie News has been dealing with the issue in a calm and factual way. When the Australian published its first article with the theme of callous Council to boot out frail old couple after bad advice based on dodgy sea-level models then all reasonable discussion ended. Ollier's article is also remarkable as it manages to convey the idea that the CSIRO relies only on models instead of actual observed data. The tide gauge at Darwin ceases to exist. "Where is this place?" He also attempts to refute the observations at a specific site by bringing in an irrelevant world satellite mean, when as fig. 7 above shows, there is good agreement between satellite and tide gauge in this region.
  11. GISTEMP: Cool or Uncool?
    WheelsOC: The UAH dataset description gives coverage as from 85S to 85N, excluding some terrain over 1500m - coverage is poor over the "Tibetian Plateau, Antarctica, Greenland and the narrow spine of the Andes". While TLT temperatures are not directly comparable to surface temperatures, it would certainly be very interesting to see how the maps compare. It would be interesting from a social perspective to publish a HadCRUT3 dataset with a coverage bias correction derived from the UAH and/or RSS data. In fact there is scope for a range of indices of this kind and a suite of online analysis tools which provide a uniform view across all the data in any combination. And I guess (and this is not my native field, so my guesses are wrong more often than not) that the agreement will be much better than the current incomplete data. We could also do a mix-and-match on land and ocean series. This is beginning to sound like real research rather than a part time blog effort though. I guess I should look at funding channels for public engagement with science·
  12. Michael Whittemore at 17:36 PM on 19 April 2012
    Shakun et al. Clarify the CO2-Temperature Lag
    @Tom Curtis It would seem I have to make myself clear, I was talking about the Milankovitch cycle affection the 30-60N region and that I don’t think the cooling you pointed out was caused by it. I also disagree that what Hass said is correct. The Milankovitch cycle did not warm a body of ocean that released CO2, there was no forcing involved that warmed the southern ocean which caused the release of CO2. The Milankovitch cycle was a trigger, a very small one at that. I stand by my point regarding CO2 being the only real forcing occurring. The orbit change and the stop of the AMOC did not add in substantial forcing, it really only caused an energy imbalance that would have corrected itself over time. I think Haas is wrong when saying H2O played any major part in a global forcing. H2O did not add anything to the energy system. I know that when there was a build up of warm ocean water in the south due to the AMOC stopping, water vapor would have played a part in the warming process, which eventually released CO2, but regarding the actual forcing that caused an actual global warming, CO2 is the only major added forcing. I understand that everything you have said is correct Tom, I just don’t give Haas the benefit of the doubt when it comes to his misguided comments.
  13. Global Surface Warming Since 1995
    Oh dear, it's C3Headlines. They seem to be a comedy goldmine. For example, this: http://topologicoceans.wordpress.com/2012/04/04/graphing-out-loud-curves-and-lines/ and this: http://tamino.wordpress.com/2012/01/29/some-questions-for-rutan/
  14. Philippe Chantreau at 16:17 PM on 19 April 2012
    Shakun et al. Clarify the CO2-Temperature Lag
    I'm not sure what William Haas' position is exactly. It seems he would like to shift the "control knob" role to water vapor. That would be hard to square with pretty much everything known about paleoclimate. In addition, it wouldn't exactly make anything easier, as burning fossil fuels releases massive quantities of water vapor along with the CO2.
  15. GISTEMP: Cool or Uncool?
    How's the polar coverage for the satellites that give us the RSS and UAH lower troposphere datasets, compared to NCDC and HadCRUT3? Do they also show relatively hot poles where those records lack coverage?
  16. Models are unreliable
    "I call these claims extraordinary". Why? Would "firing off our entire nuclear arsenal at once might lead to mass extinctions", or "a 10km asteroid impact, will lead to mass extinctions" be extraordinary claims? I would say no - both a consistent with known science. The context for that original quote and its basis from Laplace, refer to ideas that are in breach of all known science. The denialist community is making the extraordinary claim that modifying our atmosphere with a known radiative gas is somehow, in defiance of quantum mechanics and laws of thermodynamics, not going to result in a warming climate. The question over model skill is whether they are better than predicting the future than a naive assumption.(eg that man cant affect climate). The models demonstrably have that skill. Instead, Manny, you seem prepared to bet the future on the basis that known physics is wrong. I rather doubt you make similar bets against in science in other spheres (eg what you Dr tells you). Would this be because you perceive that any solution would violate your political ideals?
    Moderator Response: TC: Text edited to change all capitals into bolded. The comments policy applies for everyone.
  17. Global Surface Warming Since 1995
    Wow, another excellent post. Really too bad most skeptics won't ever read this, and then of those who do, maybe 1 in 5 will grasp it.
  18. Models are unreliable
    Perhaps, Manny, if these are indeed "claims of climate theory", as you propose, you could furnish us with the references in the peer-reviewed literature where either of these claims are made. I contend that you can't do this, as the first claim is made by a politician in a film, and the second is a personal opinion by (James) Hansen in a youTube video. See if you can find either statement in the published literature or in the IPCC reports. What you will find in the published literature: extensive discussions of empirical evidence documenting the causes and impacts of climate change, with uncertainties attached; discussions, with evidence and uncertainty, of how sensitive our climate is to change (e.g. 2C-4.5C warming per doubling CO2); discussion of model representations of the climate system, with assessment of their strong and weak points. Models validate the core propositions of our theory of climate very well. Seasonal weather forecasts are an irrelevant distraction, being both notoriously unreliable and bearing precious little in common with climate modelling. I wonder why 'skeptics' would wish to conflate the two?
  19. Cliff Ollier: Swimming In A Sea of Misinformation
    Just a quick question regarding figure 7, for those with greater technical expertise than myself: I don't get the pattern of sea level rise -why does it not rise uniformly, and why is it particularly high in the Australasian region?
  20. Models are unreliable
    Scaddenp brought me here to answer his question, so here I am. I said that extraordinary claims require extraordinary evidence. Sccadenp asks "Sorry, what is extraordinary about the claims of climate theory?" Here are two examples: "And that is what is at stake: our ability to live on planet Earth, to have a future as a civilization." Al Gore, An Inconvenient Truth. "On the long run, if this [increase in greenhouse gases] continues for centuries, that's it for all the species on this planet." John Hansen, The Runaway Greenhouse Effect (YouTube video) I call these claims extraordinary and I expect an extraordinary amount of model validation before I accept the consequences, which are also extraordinary. And, for hearing too many failed season-long forecasts from our Canadian chief meteorologist, I do not believe a minute that we understand all there is to understand about the physics of climate. Read this for fun: Balmy winter takes climate experts by surprise
    Moderator Response: Regarding your last paragraph, you need to understand that weather is not climate. See Scientists can’t even predict weather
  21. First Look at HadCRUT4
    William @17, very briefly because this is off topic - The change in mean global temperature from 1880-1889 to 2002-2011 is 0.76 C (Gistemp). As you can confirm from figure 2 above, that is approximately the same as the change from 1870 to 2002-2011. The change in ocean temperatures over the same period is 0.53 C. The difference is because land warms faster than ocean. The estimated difference from comparison of Challenger and Argos data is 0.59 +/-0.12 C, which is quite close, but if anything warmer than expected. That is particularly the case because the Challenger data may be biased warm. As the article says:
    "These numbers may underestimate the warming for a number of reasons relating to the Challenger measurements. For example, the crew worked under the assumption that the line holding the thermometer extended downward perfectly perpendicular to the surface. In reality (as they knew), it was likely to trail behind the motion of the ship, which couldn’t be kept completely stationary. That means the thermometer would measure at a depth a bit shallower than intended, yielding a warmer temperature."
  22. Daniel Bailey at 13:11 PM on 19 April 2012
    First Look at HadCRUT4
    Perhaps, william, you should read the source paper rather than a news article based on it. That would be the skeptical thing to do.
  23. First Look at HadCRUT4
    This site http://arstechnica.com/science/news/2012/04/modern-ocean-temperatures-compared-to-challenger-expedition-data.ars compares temperatures taken from the challenger expedition in 1870 with today's argo temperatures. The increase is remarkably small over the 140 years. I'd have thought it would be a tad greater.
  24. Shakun et al. Clarify the CO2-Temperature Lag
    Eric (skeptic) @129, I certainly agree that regional and even seasonal forcings are very important in understanding the transition from glacial to interglacial. In fact, that is one of the two hard lessons from that transition which are not given sufficient attention. The other is that there are without doubt tipping points in the climate system. What that transition shows us is that a seasonally strong regional forcing can under the right circumstances push the entire globe into a new stable state whose mean global temperature differs by several degrees (4-6 C) from the initial stable state. It is probable that had the seasonal regional forcing in the high NH been equally strong globally and throughout the year, the same tipping point would have been crossed, but in centuries rather than millenia. Currently we are applying such a strong global forcing. We know that tipping points exist, but we don't know how strong the push has to be to push us past any given tipping point. Further, we don't know whether there are any regionally specific factors which will amplify the risk of crossing a tipping point as the NH summer insolation amplified the very weak global forcing of the Milankovitch cycle. We are gambling at very high stakes without yet knowing the rules of the game. That, however, is not strictly relevant to this discussion. What is relevant is that the WV feedback would also have been seasonal and regional in response to the seasonal and regionally strong Milankovitch forcing. As a result it would have amplified that forcing significantly even though the global Milankovitch forcing (and hence WV feedback) was weak. However, that is not particularly relevant to the debate with William Haas. That focuses on two questions: 1) Does the WV feedback contribute more to the change in the total greenhouse effect in W/m^2? To which the answer is yes! 2) Is the WV feedback sufficient without slow feedbacks to account for the 4-6 degree increase in Mean Global Temperatures from glacial to interglacial? Haas appears to say yes to this, but the answer is clearly no! In discussing these questions, we can treat the WV feedback as global, thus gaining simplicity for our treatment, without loosing clarity.
  25. Shakun et al. Clarify the CO2-Temperature Lag
    Michael Whittemore @128: 1) Every change in temperature either globally or by latitude band prior to the Holocene (10 kyr) is natural, almost by definition. Certainly the large increases in CO2 levels and the large decreases in albedo over the period 20-10 kyr was not anthropogenic, so of course the increase in temperature from 60-90 north starting 20 kya was natural. As it happens, it was both natural and driven by the Milankovitch cycle. 2) The only forcing in the transition from glacial to interglacial was the Milankovitch Cycle. In addition to that, you had slow feedbacks (CO2 increase, CH4 increase, ice sheet reduction, changes in vegetation patterns, changes in ocean currents) and fast feedbacks (Water Vapour feedback, lapse rate feedback, changes in atmospheric dust content, changes in snow extent, changes in sea ice extent, and changes in cloud cover). The lists are not exhaustive. In order to calculate the fast feedback climate sensitivity, you can treat the changes in the Earth's energy balance due to increased GHG and reduced ice sheets as forcings, but that is merely a convenience for calculation. You should not make the mistake of thinking that they were forcings. 3) Even among slow feedbacks, CO2 or well mixed GHG generally were not the dominant players. By all accounts, the change in albedo from the change in ice sheet extent was a larger player. It is probable that for the first thousand years or so of the transition it was the dominant player, with changes in CO2 concentration not being relevant until after significant warming. Of course, changes in vegetation patterns may also have been significant players as well, with a switch from savannah to rainforest significantly decreasing albedo (although also increasing cloud cover). 4) The Milankovitch cycle did warm a large body of water. It just did it indirectly by shutting down the AMOC rather than directly by increased insolation on the body of water.
  26. Eric (skeptic) at 11:04 AM on 19 April 2012
    Shakun et al. Clarify the CO2-Temperature Lag
    Tom, I believe the things you mention are treated globally when models are not readily available to evaluate them regionally. One of the main points of the OP is that regional differences matter. I agree that the WV should not be exclusively treated globally the way I implied in 116, but I did not mean to exclude other forcings and feedbacks.
  27. Michael Whittemore at 10:09 AM on 19 April 2012
    Shakun et al. Clarify the CO2-Temperature Lag
    @ Tom Curtis 124 You say “20 kyr: temperatures start to rise from 60 to 90 degrees north, presumably due to Milankovich forcing, temperatures start falling from 30 to 60 degrees north” I personal think that the 30-60N cooling is completely natural, you can even see that it starts to warm before the seesaw event takes place. The Milankovich cycle only warms the far north, and if the AMOC is working, it would be the main driver of climate in the 30-60N region. 30-90N only started cooling when the AMOC stops. You say “The Milankovitch forcing heated that water indirectly by shutting down the AMOC, an important subtlety Haas does not mention, but his statement that it took 2,500 years for the Milankovitch forcing to trigger the rise of CO2 levels is correct.” Haas does not say that the Milankovitch forcing triggered the CO2 rise, he says that it warmed a large body of ocean which released CO2. The forcing from the Milankovitch cycle could not have warmed a large body of ocean and forced it to release CO2. It is the trigger not the forcing. There was no forcing that warmed the southern ocean, the Earth just had an energy imbalance caused by the AMOC stopping. @ Tom Curtis 127 We are talking about forcing, the only forcing other then CO2 during the last glaciations was the Milankovitch cycle. I don’t even think it can be called a forcing, it is an energy imbalance caused by the orbit of the Earth redirecting sunlight. The only considerable forcing taking place is the release of CO2. Other GHG are short lived. To be clear, you could have everything taking place during the LGM but without the release of CO2, there really should be no added warming to the system. I know the Shakun paper says 7% of the warming took place before the rise in CO2 but I personal think that with more proxy records the global average temperature should not rise until there is a release of CO2.
  28. Daniel Bailey at 09:33 AM on 19 April 2012
    First Look at HadCRUT4
    fydijkstra is no skeptic, but a dyed-in-the-wool denier. I suggest not feeding this woolly t-roll.
  29. Mars is warming
    While extraterrestrial climates and weather are interesting in their own right, and atmospheric compositions and temperature responses can be used to calibrate physical models here on Earth, it is irrelevant to us here whether or not it is warming on them as a result of the sun's varying output - we have infinitely better measurements of solar radiation here and its effect on our planet, which is what matters. It's just an invention that denialists use to try to mislead gullible people with something that sounds believable without all the facts. Whatever other planets are doing, in spite of the Sun's output having been at its lowest for years, our Earth is still warming.
  30. PMO Pest Control: Scientists
    "A behind-the-scenes look at a federal scientist 'muzzling' incident" is a must read/listen for anyone following this disturbing situation in Canada.
  31. First Look at HadCRUT4
    fydijkstra @8, "(do not ask me for links, this is common knowledge)." Please, this is a science site, as such please quantify your claims and provide links when attrobuting claims to scientists so that others can validate your claims. Also, thank you for coming here to demonstrate the misguided/misinformed understanding that "skeptics" have about the science.
  32. First Look at HadCRUT4
    I was wondering how long it would take a fake skeptic to come along to try and derail the thread. Unfortunately for them they seem to have not read the post in its entirety. Skywatcher thanks for showing just how wrong fydijkstra is.
  33. First Look at HadCRUT4
    Just on the offchance that fydijkstra is not being a Poe, here's the last 15 years of HadCRUT4, using the excellent SkS temperature trend calculator and the viewer is left to decide whether they think the world has been warming since 1996 (15 years ago): HadCRUT4 last 15 years 15 years of course is not generally long enough to clearly show trends in temperature data (even though I think most pepole would agree there appears to have been some warming since 1996), so lets extend the trend to the past 30 years: HadCRUT4 last 30 years fydijkstra, do you still think "the warming trend in the last 15 years is zero", given the above plots from the same dataset?
  34. Shakun et al. Clarify the CO2-Temperature Lag
    Eric (skeptic) @126, the changes in albedo from ice sheet melt in the transition from glacial to interglacial are strictly regional phenomenon, not global. Yet they are treated as a globally averaged effect in any discussion of the issue, and in any model except full Global Circulation Models. Even the Green House Effect from increasing CO2, and come to that the Water Vapour feedback are not everywhere the same because of differences in temperature between the equator and poles (among other reasons), and are treated as globally averaged effect. Choosing the WV feedback from the Milankovitch signal, and only that feedback to not be treated as a globally averaged effect is pedantry, and an inconsistent pedantry to boot. It adds nothing to the discussion.
  35. First Look at HadCRUT4
    fydijkstra @8:
    "The only conclusion can be, that the warming trend in the last 15 years is zero. One does not need to be a climate sceptic to see this."
    One does, however, have to fail to understand basic statistics to believe this myth, even ignoring the massive heating of the oceans during the time period in question mentioned by Composer @9. Perhaps you should examine the temperature trends referenced at the end of the above post. As Composer @10, I hope we're just victims of Poe's Law here.
    Moderator Response:

    [DB] No Poe here. fydijkstra is a long-time fake-skeptic with a history of drive-by thread hijacking at SkS. Between mystical "Cycles" and "It's all a conspiracy" (indeed, it's conspiracies-all-the-way-down-Wednesday), no thread is safe. A sample of his work:

    "@Bernard J. Why should anyone deny these numbers? It is a huge blessing, that the earth is able to store all this heat, without harmful effect on the climate! The oceans are a perfect heat buffer. If we had no oceans, we should invent them! They are the best weapon against global warming."

    Everyone, DNFTT

  36. Robert Murphy at 07:39 AM on 19 April 2012
    First Look at HadCRUT4
    @8 "This means that there is no significant difference between 1998, 2007 and 2010. The only conclusion can be, that the warming trend in the last 15 years is zero. One does not need to be a climate sceptic to see this." It means no such thing. One does not need to be a statistician to see that taking 3 data points and ignoring all the rest of the data is rubbish. Hadcrut4 and GISS both show a warming over .11C since the beginning of 1998. Since the end of 1998 (after the huge El Nino), they show over .16C of warming. Your warming trend of "zero" is nonsense. "Some years ago, Phil Jones said, that 15 years without warming were the maximum that could be expected from the present climate models (do not ask me for links, this is common knowledge)" Please provide links anyway; you don't get out of substantiating your claims by hand-waving away the need to do so.
    Moderator Response: [DB] The "Phil Jones said" meme is off-topic on this thread (sorry).
  37. First Look at HadCRUT4
    If on the other hand I have just been succesfully taken in by sarcasm/a Poe, let me be the first to admit to having egg on my face.
    Moderator Response: [DB] No Poe-egg anywhere.
  38. First Look at HadCRUT4
    fydijkstra, between Foster & Rahmstorf's paper showing that warming is unabated when one accounts for ENSO & solar variation and the fact of unabated warming of the oceans, your claim appears to be decidedly false, in addition to verging on IMO baseless conspiracy-mongering.
  39. First Look at HadCRUT4
    Congratulations! It can no longer be said, that 1998 was the warmest year ever, according to CRU. They succeeded in rewriting their data. But it is a Pyrrhus Victory. Now 2007 and 2010 are both 0.01 degrees warmer than 1998, acoording to HadCrut. This means that there is no significant difference between 1998, 2007 and 2010. The only conclusion can be, that the warming trend in the last 15 years is zero. One does not need to be a climate sceptic to see this. (-Snip-)(do not ask me for links, this is common knowledge). So, even with HadCrut4 we are on the edge of rejecting the present climate models. One does not need to be a climate sceptic to see this.
    Moderator Response: [DB] Off-topic perambulations into "Phil Jones said" territory snipped. And it's "Pyrrhic".
  40. First Look at HadCRUT4
    Adding all these new monitoring stations is great but if they are new stations and not stations with long historical records, they will only be valuable in the future as they establish a new base line. Each time you add a new station you reset the base line. In a sense it would be better to stick with stations that have records at least back to the 1950's
  41. Cliff Ollier: Swimming In A Sea of Misinformation
    Old Mole - fixed the "previous half-decade" segment. I think technically Greenland is part of the North American continent, but it seems inconsequential to me.
  42. Eric (skeptic) at 03:00 AM on 19 April 2012
    Shakun et al. Clarify the CO2-Temperature Lag
    Part of the confusion may be that Milankovitch forcing is not a earth-averaged W/m2 forcing. There is a component of W/m2 forcing for part of the earth, specifically longer NH winters. As those winters shorten towards the end of the glacial period, there will be weather and climate changes including localized water vapor increases. But William Haas talked about global average water vapor as if Milankovitch were a simple global average W/m2 forcing which it is not.
  43. Shakun et al. Clarify the CO2-Temperature Lag
    So what we're quibbling about here on the basics is the definition of "forcing" where H20 is concerned. William may be insisting, if he is actually insisting, that WV is a forcing post LGM because it is the largest contributor in GHG warming. If so, no -- orbital changes are the forcing. WV is a feedback, and it is always the dominant element in GHG-based warming (but not the controlling factor -- like a bad mob film, WV is the "muscle" that does the bidding of the little guy in the shadows--Joe "CO2" Maguire--but doesn't do much on its own, unless the big big boss (orbital) needs some long-term project done -- ooo, I see a climate-as-film-noir project). Sublimation rate does not change of its own accord. WV will not increase of its own accord on the climate scale. It is always a feedback to whatever forcing. CO2, likewise, does not increase of its own accord. We don't speak of AGW-concurrent permafrost CH4 mass release as a forcing. We shouldn't speak of post-LGM WV increase as a forcing or as a trigger. I don't think that is William's intent in 113. If he clings to the idea that WV is a trigger, a forcing, then we need to question his ability to honestly engage. If, instead, he means that WV played a more crucial role than CO2 in early post-LGM warming, then that's a good, debatable position.
  44. Cliff Ollier: Swimming In A Sea of Misinformation
    Two minor quibbles: "Sitting atop the Antarctic and Greenland continents are immense sheets of ice kilometres thick." Last time I looked, Greenland wasn't a continent. "contrary to popular perception, there was slowdown in the heat uptake in the upper ocean (0-700 metres deep) layers from 2003-2008, when compared to the half decade." Errr ... what half-decade? Best wishes, Mole
  45. Shakun et al. Clarify the CO2-Temperature Lag
    Michael Whittemore @123, If you look at figure 4 in the original post, you will see the following sequence: 20 kyr: temperatures start to rise from 60 to 90 degrees north, presumably due to Milankovich forcing, temperatures start falling from 30 to 60 degrees north; 19 kyr: temperatures start falling from 60 to 90 degrees north, and continue falling from 30 to 60 degrees north. Temperatures from 30 degrees north to 60 degrees south start rising; 18 kyr: temperatures start rising from 60 to 90 degrees south; 17.5 kyr: CO2 levels start rising, temperatures cease falling from 30 to 90 degrees north. That makes it 2,500 years from the onset of the Milankovitch forcing until tropical and southern hemisphere waters were warm enough to start a steady rise in CO2 levels. The Milankovitch forcing heated that water indirectly by shutting down the AMOC, an important subtlety Haas does not mention, but his statement that it took 2,500 years for the Milankovitch forcing to trigger the rise of CO2 levels is correct. Haas may in fact just be very confused on certain points, or he may be very subtle. He may have adopted the approach of making egregiously wrong statements and then defending a reasonable position which can be mistaken for the false position he originally stated. If that is his game, by not acknowledging where he is correct, but clearly distinguishing it from his initial statements you fall for a rhetorical trap and find yourself arguing against true beliefs in the mistaken opinion that you are arguing against false beliefs. In doing so, you hand victory to the rhetorician how laid the trap. I am not saying that is what Haas is doing. As I said, he may just be confused, or even just have stated a reasonable position in a very confused way. Regardless, he has persistently made claims which are false, even absurdly false as you have highlighted; but defended the reasonable position that H2O was a significant positive feedback during the first 2,500 years of the glacial/interglacial transition. To avoid continuing the confusion, Haas needs to clearly answer my questions in 118. But to avoid continuing the confusion we need to recognize when he is right, but clearly state why what he is saying that is correct is not the same thing as, and does not support those things which he has said which are wrong.
  46. First Look at HadCRUT4
    How much of the change is due to the HadSST3 and how much is due to CRUTEM4? This is rather crude and will blur the distinctions somewhat, but working from the merged land/ocean maps (I should really use the separate land and ocean files) I get the following 15 year trends 1996-2010: HadCRUT3: land: 0.255 C/decade ocean: 0.058 C/decade HadCRUT4: land: 0.310 C/decade ocean: 0.088 C/decade Difference: land: 0.055 ocean: 0.030 (Don't expect these number to match the distributed values.) Taking into account the different areas covered, the ocean looks as though it's a slightly larger effect. However because I have use the global rather than land and ocean maps I'm overestimating the ocean trend and underestimating the land trend. I guess the two play a similar role. That doesn't come across in the graphic, because the ocean change is a small change smeared over the whole map. (I will try and do the calc properly at some point.)
  47. Michael Whittemore at 00:53 AM on 19 April 2012
    Shakun et al. Clarify the CO2-Temperature Lag
    I cant believe we are even wasting our time on William Haas. He clearly thinks that the 7% warming seen during LGM was global, and that it was caused by H2O. Just look at his comments below “To enhance or continue global warming is atmospheric CO2 really necessary to explain it? What about H20?” Comment can be seen here “There is no imperical data uncovered by this article to show that in the first 2,500 years since LGM that the green house gas, an increase in average atmospheric H2O did not have some roll in global warming” Comment can be seen here From the very start we have all been trying to disprove these statements. We all know that the initial forcing was the change in Earth’s orbit, H2O was not the forcing just the feedback. Even when the (AMOC) stopped, there was no added forcing that warmed the South it was just an energy imbalance with less warm water going north and more staying in the south. Even in William Haas resent comment he clearly tries to attribute H2O to global warming, even though we all know that the 7% warming seen during the LGM was nowhere near global. Just read the comment below “During the time I am talking about there was CO2 in the atmosphere but because it did not increase, its increase could not have contributed to global warming.” Comment can be seen here @Tom Curtis you say that “William Haas's comment at 113 is correct in every detail.”. You really think that William’s saying “Apparently it took 2,500 years for the Milankovitch forcing to heat a large enough volume of ocean water to effect global CO2 levels.” Is true?
  48. New research from last week 15/2012
    #3 & 4 - the lead author, Ben Booth, has made a couple of comments about the paper and blog/media reactions at Tamsin Edwards' blog: http://allmodelsarewrong.com/how-to-be-engaging/#comment-1084 http://allmodelsarewrong.com/how-to-be-engaging/#comment-1094
  49. 2012 SkS Weekly Digest #15
    As an avid (non contributing) reader... Another angle on 28 is that, IMHO, denial through being Sciencey or matherterbation has just about run its course. It's been important and informative to do thorough take-downs and those are excellent resources; but now I'm always surprised when the same-old-same-old arguments are trotted out (except by politicians!) and would be equally surprised to see any new tropes which really take hold, be they sciency or 'social'... how much of a real splash did the NASA administrators joint letter really make? SkS is settling, seems to me, into more posts of excellent reviews and takes on new research. And this is right. Seems to me it's time to spend less time reacting and to take back the lead both in terms of understanding the severity and impacts of AGW and policy. We're told by Chris Mooney that 'conservatives'* are good leaders in a crisis - more and more are now realising the facts of AGW and are likely to be looking for material to use in combating it... those who've changed, or made up, their mind and come to SkS for information on AGW should find a friendly place. *I put quotes there as I'm aware the SkS contributors are actually from a very broad Church ... and not just liberal-minded, pink-o heathens ;)
  50. GISTEMP: Cool or Uncool?
    On the previous post, Skywatcher pointed out quite rightly that the rectangular projection I have used in the maps can create a misleading impression, because the area is exaggerated as you move away from the equator. This inflates the apparent impact of poor coverage at high latitudes. All the conclusions of this post are based on the global temperature averages, not on the illustrations, which are provided as an attempt to explain what is going on. However there is certainly one point which needs to be demonstrated more clearly, I'll try and clarify. In determining the impact of poor coverage at a given latitude, there are three factor at play: The fraction of the Earth's surface covered by that latitude band, the amount by which temperature anomalies in that latitude band differ from the global mean, and how much of that latitude band is missing. In the case of the Arctic, these pull in different directions. The Arctic covers a relatively smaller area than a corresponding latitude range at the equator, but the temperature anomalies are changing much more quickly and the coverage deficit is much more significant. How do these effects play out? That is shown in the following figure: To generate this figure, I took the GISTEMP gridded maps and reduced the coverage to match HadCRUT3 over a 30 degree latitude band, leaving the rest of the map untouched. I then calculated a temperature series from the gridded map series. I repeated this 6 times to produce 6 temperature series. I then took the difference with the original full-coverage data. The results are shown above. Each line represents the bias added to the total temperature series by the loss of coverage in that latitude zone alone. As you can see, the Arctic is the biggest contributor to the recent cool bias of HadCRUT3, followed by the northern mid latitudes. The Antarctic actually provides a warm bias, but one which has been declining since 1998, thus actually adding to the cooling bias since that date. In fact every zone except the southern tropics has been contributing to the cooling trend in HadCRUT3 over the last 13 years. In summary: When calculating area averaged global temperature anomalies, the GISTEMP data suggests that the Arctic, despite it's comparatively small area, is the largest single contributor to the cool bias due to poor coverage in HadCRUT3. The NCDC data suffers from the same problem at high latitudes, although its mid-latitude coverage is better. The implications for HadCRUT4 are interesting.

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