New rule for high profile papers
New rule: When declaring that climate models are misleading in a high profile paper, maybe looking at some model output first would be a good idea.
This is a reference to an otherwise interesting paper in Nature this week (Graversen et al) on the vertical structure of heating in the Arctic in recent decades. One of the key results is that during the summer, when temperatures near the surface are constrained to be close to zero by the presence of open water and sea ice, the troposphere heats up anyway. The mechanism for this heating is hypothesised to be related to changes in atmospheric heat transport. So far so good.
But towards the end, there is this curious line:
Our results do not imply that studies based on models forced by anticipated future CO2 levels are misleading when they point to the importance of the snow and ice feedbacks. …. Much of the present warming, however, appears to be linked to other processes, such as atmospheric energy transports.
The clear implication is that climate models don't suggest that atmospheric heat transports will change and that all polar amplification in those possibly misleading models is driven by snow and ice feedbacks. But is this correct? Well, it's hard to tell from this paper because they don't look at any model results!
This didn't stop the AP from declaring the heat transports to be part of some "natural and cyclical increase"! For National Geographic it was just 'mysteriously occurring'….
But in order to see what models have to say, all one has to do is look. With the easy availability of the CMIP3 archive, it's not too difficult to do the analysis for all the IPCC AR4 simulations for this exact period. As a short cut (and just because there is an easy interface) you can also go to the GISS archive and to pull down the figure for the summertime (Jun-Aug) temperature changes in the "all forcings" run for the same time period (1979-2001). If you do so, you'll see that in the Arctic, the models also suggest that summer time surface changes are small and that there is heating aloft - similar to the analysis in this paper. The match to the ERA-40 analysis isn't perfect by any means (but the match between different analyses products is not that great either). More analysis would need to be done to work out what was forced and how large the weather noise is etc, but the basic phenomena seems to be quite universal and not mysterious at all.
The point is that this isn't difficult stuff, and it should be standard practice to at least give a cursory look at what models actually show before accusing them of being misleading.
4 January 2008 at 8:44 AM
Thanks, Gavin, for clarifying this. I saw this at New Scientist (with plenty of comments) and was wondering what it meant.
http://environment.newscientist.com/article/dn13134-melting-ice-may-not-explain-warming-arctic.html
4 January 2008 at 8:45 AM
Typo catch(?): “when surface temperatures near the surface”…as opposed to surface temperatures where?
[Response: thanks - gavin]
4 January 2008 at 9:00 AM
This is a ridiculous post. After reading the paper I did not get the impression at all that the authors wanted to suggest that climate models are misleading. I wouldn’t be surprised that a reviewer insisted on this paragraph in the conclusions, while the authors didn’t want to mention this at all.
It is bad enough, that nowadays you cannot publish in Nature anymore without having to add these kind of paragraphs. Your weblog is not helping science by writing articles like this, but is creating an atmosphere in which scientists constantly have to excuse themselves if they want to publish anything that might not fully match the IPCC conclusions.
[Response: Huh? All I’m asking for is that statements be backed up. If the models really don’t match, then that’s interesting too. But careless throwaway lines like this lead to plenty of misleading press and I’m not the only one who noticed (see Climate Feedback for instance). - gavin]
4 January 2008 at 9:10 AM
How is it that this wasn’t picked up during peer review? It would seem that inclusion of some analysis of the current models results would improve the paper which is the purpose of peer review.
4 January 2008 at 9:26 AM
PJGrefhorst, did you bother actually reading what Gavin wrote? For one thing, we’re talking about the models here, not IPCC conclusions. And what Gavin is saying is that there isn’t a mismatch. Do you have any basis for your speculation that the authors were “forced” to include said paragraph? Methinks you ought to go back and read the comment a bit more thoroughly.
I was also struck by the press accounts here. They didn’t seem to have any understanding that athropogenic greenhouse forcing is only one of several factors at work in climate. It’s just that anthropogenic greenhouse forcing will be operative for several hundred to several thousand years, and so will have a very serious effect on climate. The fact that there could be other fluctuations or variability does not alter this conclusion.
As William James said: “A difference which makes no difference is no difference at all.”
4 January 2008 at 9:36 AM
When I read this I immediately thought of Dian J. Seidel’s paper wherein the “the structure and circulation of the atmosphere…[causes an]…expansion of the tropical region toward the poles”.
Could this process be behind the “atmospheric heat transport” mentioned above? Or no?
Because the Seidal result is thought to be AGW related, so could there might be
causality at one remove.
4 January 2008 at 9:54 AM
This is an interesting paper. The line you note seems to be a balancing act.”Our results do not imply that studies based on models….are misleading” allows the authors to say they are not calling the models out of line, but the the whole section implies that the models are. Have your cake and eat it too. Their science would be stronger if they looked at the model results and used this to correlate and contrast and put their work in perspective. But their paper is of more newsworthy nature with the small section added. Is this section inclusion then driven by science? One question? Why would the snow and ice feedback from the surface not be powerful enough to matter to air temps at 2 km even in summer, just due to the reduced importance of long wave radiation emission in the overall heat budget?
4 January 2008 at 9:57 AM
Hi Ray,
I don’t have any basis for this speculation, but if you read the article it seems to come out of the blue. Maybe RealClimate can ask the authors to comment on this paragraph.
PJ
4 January 2008 at 9:58 AM
Another relevant issue regarding this paper is that that their study, based on data from the ERA-40 reanalysis, ends in 2001. A lot has happened since then. If one looks at latitude by height cross section of temperatures from the NCEP/NCAR reanalysis, expressing 2001-2007 as anomalies with respect to 1979-2007, there is a very clear signal of stronger warming at the surface over the Arctic Ocean during autumn. This appears to be quite consistent with the strong losses of summer sea ice since about 2001, leading to large heat fluxes to the atmosphere in autumn. The signal is there even when eliminating 2007, when late summer ice extent was at a record low. Put differently, the analysis in the Graverson et al paper ends at just about the time when the real “action” begins.
4 January 2008 at 10:01 AM
From the paper:
“Our results do not imply that studies based on models forced by anticipated future CO2 levels are misleading”
From the post:
“it should be standard practice to at least give a cursory look at what models actually show before accusing them of being misleading.”
They don’t accuse any models of being misleading.
4 January 2008 at 10:16 AM
“Climate model experiments indicate that when global temperature rises, Arctic snow and ice cover retreats, causing excessive polar warming…Snow and ice feedbacks cannot be the main cause of the warming aloft during the greater part of the year, …We conclude that changes in atmospheric heat transport may be an important cause of the recent Arctic temperature amplification.”
They clearly imply that climate models do not take into account “atmospheric heat transport”
4 January 2008 at 10:25 AM
No, they don’t accuse any models of being misleading. When they write
When linked with the sentence you’ve posted, as it is in the paper and in the original post, it certainly appears they imply that the models ignore possible changes atmospheric energy transports. Which is what the original post is complaining about.
Or do you read that sentence in another way? If so, perhaps you can share your understanding of what they mean?
4 January 2008 at 11:23 AM
I was actually asked about the paper coming out by the AP reporter (Seth Borenstein) and sent in the following comments. I was not, however, quoted in the article (my explanation was perhaps a bit technical, but done to refute the rather strange conclusion being discussed) and the perspective in the AP article ended up not in accord with my comment. I put it here as it might be of interest.
Mike MacCracken
Hi Seth—Well, an interesting paper, to which one might say of course to their point that changes in transport have been playing a role, but I think they jumped the gun a bit by suggesting that it appears that the snow and ice albedo feedbacks were not significant factors in contributing to the response. I say this because it appears to me that they left out consideration of infrared radiation as a process that could connect changes at the surface and with changes in the layer aloft. For example, if transport brings in more water vapor, then the IR flux to the moistened layer will increase and cause warming, especially if albedo feedback provides more warming at the surface; it is just not obvious that the change in albedo near the surface has to cause the largest influence near the surface—radiation can carry energy changes to higher layers. [And, indeed, as they cite from reference 12, one will get some amplification even without albedo feedback, likely because at high latitudes the GHG effect is responded to mainly by temperature change since water vapor is so low (per Clasius-Clapeyron relationship), whereas in lower latitudes a larger fraction of the GHG-trapped energy must go into evaporation—so there is sort of a Bowen ratio effect.]
Quite clearly from Figure 1(d), in the autumn the whole layer can be affected by what has happened at the surface (they sort of indicate this was by transport, but it could as well be by changes in radiation terms). That the albedo effect itself is strongest in summer in terms of energy fluxes is true, but the energy accumulated over the summer in the ocean due to a lower surface albedo has its greatest impact on air temperatures in the fall when the heat is returned to the atmosphere due to the absence or thinness of the sea ice—so delays are expected.
This is not at all to say that their suggestion that circulation changes make a difference is incorrect—of course that should be expected as well, for the atmosphere will respond to changes in energy sources and sinks by carrying energy and water vapor around. Their calculation of energy transport seems to include latent heat (see Methods section), but their figures focus on showing the changes in the temperature field (instead of equivalent potential temperature—which would account for the latent heat term, and the vertical movement term as well, which could be affected by changes in the large scale overturning circulation). They did not seem to compare their analytic results to those of models including all the various terms to see if there are differences (e.g., relating to an incorrect representation of albedo feedbacks); what the models do is keep track of everything quantiatively, so they overcome some of the special focus of this paper’s analysis.
Basically, I’d say, this is a fine analysis as far as it goes, but I don’t think one can evaluate the relative role of surface albedo impacts in this way, especially as everything is interconnected. An energy change in one place, for example near the surface, will trigger changes in circulation, etc., so is the circulation change related to the albedo effect—just not clear from this analysis. So, I don’t think this paper will in any way upset scientific understanding—though it is certainly possible some of The Skeptics will claim something.
Best, Mike
[Response: Thanks Mike, this is very englightening. Seth Borenstein is generally a very good, careful journalist, but nobody is perfect, especially when the subject matter deals with some rather technical issues. Its seems there is a lesson here for us. Namely, that tempting as it may be to get into technical nuances, we need to provide as concise and non-technical an explanation of these things as we can when the material is intended for popular consumption. - mike]
4 January 2008 at 11:25 AM
Re # 3 :
“Your weblog is not helping science by writing articles like this, but is creating an atmosphere in which scientists constantly have to excuse themselves if they want to publish anything that might not fully match the IPCC conclusions.”
I think that what’s helping science even less is to start from the premise that everything in the IPCC report is evil, and to constantly ask climate scientists to find issues with it. I see a lot of this now on the blogosphere and it is quite annoying. This example suggests that it now begins to infuse the literature as well.
While healthy skepticism is the basis of scientific methodology, there are people for whom IPCC-trashing has become the new orthodoxy. Personally, i think Gavin is right in pointing out when such excesses outcrop in the literature without any form of backup.
Especially when it takes 10 minutes to verify that the devilish GCMs actually don’t do what they are accused of…
[Response: Well put Julien. Thanks for stopping by - mike]
4 January 2008 at 12:13 PM
So, how do we train editors to call someone like the RC folks before they republish the rubbish? If an editor at AFP (http://afp.google.com/article/ALeqM5hWas1ATOsqlUcRqZ021v5ubeO3IA ) had called Gavin, the poorly phrased material would not have been republished in many local newspapers.
I am coming to think that newspapers in the US pander to what they think their readers already believe, and do not try to educate and correct misconceptions held by the public. I cite as exhibit 1 the NYT New Year’s day piece “In 2008, a 100 Percent Chance of Alarm “ by John Tierney. (http://www.nytimes.com/2008/01/01/science/01tier.html?_r=1&ref=science&oref=slogin)
All I can say is no wonder Tierney had a hard time getting papers published in peer reviewed journals.
4 January 2008 at 1:39 PM
Are you saying that the models predict very little warming at the surface at high latitudes (Arctic)?
All the zonal projections I have seen (including those in the IPCC reports) show the largest surface temperature increases will occur in the high Arctic.
This is clearly outlined on Page 15 of the Summary for Policy Makers - Working Group 1 of IPCC AR4.
http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_SPM.pdf
[Response: The warming is very clear in the annual or winter time means - the summer was the point of contention here. Check out the GISS model results (as indicated above) for different seasons and you’ll see. - gavin]
4 January 2008 at 2:00 PM
In #15, Aaron Lewis writes:
“All I can say is no wonder Tierney had a hard time getting papers published in peer reviewed journals.”
Tierney is one of the two NYT token conservative op-ed columnists. His op-eds are uniformly silly, even by the relaxed standards of token NYT conservative op-ed columnists. He is not a scientist, although he does occasionally play one in the NYT editorial pages.
Best regards.
4 January 2008 at 2:49 PM
Aaron, Tierney is a columnist, a ‘bertarian spin writer.
How do you come by your belief that “Tierney had a hard time getting papers published in peer reviewed journals” and why do you trust whoever told you that?
He’s not a scientist. He doesn’t do peer reviewed work.
4 January 2008 at 2:50 PM
It looks to me, as one that’s made a minor hobby of watching the jet-stream and the weather pattern shifts from satellite over more than years, that there is a tendency for a new or at least a stronger Hadley cell system over the newly exposed Arctic ocean. This tendency persists up until the ice solidly freezes over in November.
This would be the effect, I assume, seen by the Nature paper, and should also appear in any good model.
The new Hadley cells I see are pretty intense if they can be seen by eye. They also seems to transport major quantities of heat, as the whole Arctic heats up when one occurs. The one that’s easiest to see is the one that forms around the Bering Straight.
4 January 2008 at 3:30 PM
New Rule: Publish a “high profile” paper of your own instead of enlisting the drones of Climate Change to comment. Gavin, if you have a problem with this paper then publish a rebuttal and submit it, increasingly this site has become you and your colleagues soapbox for non-relevant musings regarding the work of others. I do not worry about quotes in mainstream media and single lines taken out of context from published works. Perhaps the op-ed attitude of James Hansen has permiated your culture so far that you feel that this is your personal mission, who knows, but lets have more of the science (and less critiques on grammer or perceived slieghts against your work).
Next what about the actual subject and conclusions of the paper itself? Any useful comments?
[Response: My publication record speaks for itself. But frankly, you complete misunderstand the purpose of my post. There is no issue with this paper that would merit a comment to Nature, let alone having Nature actually publish it. This is simply a comment about loose language and the ensuing press confusion. Presumably you’re not in favour of that? This has nothing to do with any faults of grammar or comments on my work (I didn’t see any). If you don’t like my musings, you don’t have to read them. - gavin]
4 January 2008 at 3:40 PM
Gavin:
Going in search of monsters seems a symptom of the disease this site is supposed to cure. Oliver Morton is well placed to fisk both Nature and the press coverage , and his Climate Feedback post concludes :
“So I’m a little surprised that the paper is being seen as evidence that the human role has been exagerrated. ”
This is not to deny they are out there-
http://adamant.typepad.com/seitz/2008/01/night-of-the-li.html
But merely to observe that Graversen et al. are under no obligation to base their emphasis, or lack of it, on other people’s enthusiasms.
[Response: Of course not. It just happens to be a pet peeve of mine that statements like ‘models show’ this or that often occur without any reference to what models actually show and under what circumstances. At times, this has consequences beyond the few scientists that read that far down in the paper. - gavin]
4 January 2008 at 4:25 PM
RE #20 & “publish a rebuttal”
The problem is everyone swarms over the original article and it gets publicized, and corrections and rebuttals are often ignored, at least by the mainstream media and media consumers. With the possibility of dangerous outcomes from GW, respected journals should be extra-cautious in publishing misleading info that might detract from mitigation efforts.
A mistake on the other side, such as overestimating the danger from GW, would not be harmful, since as we all know mitigating GW (even if it is not happening…and it is) would be of great help in saving people money and boosting the economy, without lowering living standards or productivity. Sort of a win-win-win-win situation, when you factor in better health and wealth and well-being from reducing other enviro problems to boot.
It’s better to err on the side of caution than danger.
4 January 2008 at 4:40 PM
Careful wording in papers is important in the current environment.
The environmental news network sends out a daily e-mail with summaries of news reports about environmental politics and science mostly from Associated Press and Reuters. News reports about recent climate science papers come out every other day. From this week alone:
“2008 to be in top ten warmest years”
“First-ever study to link increased mortality specifically to carbon dioxide emissions”
“Trees are not the answer to global warming”
Any poorly worded papers will spread fast and far.
The scientific papers are read in the contrarian circles with an eye to spot poorly worded parts and then use these parts to sow doubt. Even the most inadvertent misstatement will be talked up on the contrarian websites.
I would go as far as recommend getting a lawyer to parse the language before releasing the paper.
#18 (Hank Roberts), #17 (Jim Dukelow) et al the NRDC’s blog has an interesting post about the Tierney piece
http://switchboard.nrdc.org/blogs/awetzler/nice_column_but_i_think_your_a.html
4 January 2008 at 4:48 PM
I don’t think that we need any “new rule” restricting scientists to only expressing their opinions in the pages of peer-reviewed publications (which generally have very limited space for comments, anyway). Frankly, this sounds like a rhetorical stratagem to try to muzzle opinions that you don’t like. Go to a scientific meeting or a seminar at a university sometime–you will see scientists standing up and expressing critical opinions quite freely, without submitting them first to peer review. Scientists certainly appreciate the value of peer-review, but it a mechanism for quality control, not censorship of scientific discourse.
4 January 2008 at 4:55 PM
Re 19. Tierney claims to be a science writer and this article was in the Tuesday Science Times section. It is a fluff piece that reflects the intellectual laziness found in most of his writing, and about which he actually boasts in his NY Times personal page. Unfortunately, appearing in the Science Times, it will be taken seriously by many of the uninitiated. It is a mystery to me why the Times continues to sully its reputation with a guy like this.
4 January 2008 at 5:29 PM
There is one problem, I believe, worth addressing on RC when responding to articles. In order to avoid projecting one’s own biases or negativities I suggest that we reflect more carefully on what we are reading so as not to see what is not there. The old story is that we see what we want to see and this can also be true in response to scientific articles. I’m not a scientist but I do teach courses dealing with mis-perception. Though RC obviously strives to be unbiased it is still subject to the use of words, and words have their own emotional content. Everyone within e-mail range tends to have a hurry-up mindset because of the immediacy of e-mail, which means that emotions and feelings are engaged in rapidly. This hurry up mindset makes us respond quickly and often far more emotionally than intended, resulting in unintended consequences. My recommendation, for what it is worth is to read over at least three times, and with care, any article that you are responding to, taking into consideration our very human tendency to mis-perceive.
4 January 2008 at 7:42 PM
Re #20. This site has been and continues to be in large part a very good site for the attribution of global climate change. I find, as one of the “drones” that whether you’re an protagonist or skeptic, you have to agree that the standards of the contributors demand technical accuracy above all. As one of the protaganists, there have a few occasions when I’ve let feelings get in the way of facts and have had posts that were unable to make the cut.
As far as Post #3. Any one who does meticulous, carefully objective science has nothing to fear from this site. Papers both pro and con have been reviewed in RC and the detailed discussions that follow lead to a better understanding of the issues.
4 January 2008 at 8:26 PM
Gavin:
Did you look at data from any of the other models in the archive? I took a quick look at ensemble averages from the GFDL CM2.1 and NCAR PCM 20th century runs and neither of those models do a good job of reproducing the vertical structure for JJA as shown in Fig. 1 of the paper.
Perhaps there is some basis for the statement that caused all the fuss, although it certainly would have been more convincing if there was some indication that the authors had looked at the model data.
[Response: No. But if you make a figure of the summer-time (JJA), 1979-2001 trends - either ensemble means or individual runs, I post them along with the GISS results as an update. If anyone else wants to pile in, I’ll post up any similar analyses as well. Maybe if you sent me the North Pole vertical profile trend data, I could actually plot it all up consistently. - gavin]
4 January 2008 at 8:37 PM
There is a good discussion of this issue also at Andrew Revkin’s New York Times blog called Dot Earth, and he links to Tierney’s original newspaper column and blog post. It makes for interesting reading, and the comments are coming in fullspeed ahead. It’s titled: “Alarming Weather and Global Warming” and the link is here:
http://dotearth.blogs.nytimes.com/2008/01/04/alarming-weather-and-global-warming/
Money quote: “And, as I blogged recently, the media definitely have a tendency to get seduced by the “front page thought” when dealing with questions about climate and, say, hurricanes, and thus can miss the legitimate questions still surrounding the science that explores links of that sort.
John and I often disagree, and we definitely have different roles in the media landscape. But on this overarching theme there’s synchrony.” (Revkin)
4 January 2008 at 9:17 PM
“Any one who does meticulous, carefully objective science has nothing to fear from this site. Papers both pro and con have been reviewed in RC and the detailed discussions that follow lead to a better understanding of the issues.”
Very well said. Science may begin with basic observations but it doesn’t end with peer review. If all the scientists were a bunch of super loyal frineds (read clique) then it wouldn’t be reproducible or honest. Science is not a battle of opinions. There are always multiple working hypotheses about any question in nature and most scientists tend to favor one or two particular hypotheses. But all hypotheses are subject to testing and retesting. That is the scienific method. So what’s wrong with critiquing people’s papers? Why shouldn’t RC be a forum where such a thing is done? Peer review is not the end all means to truth. Most scientists appreciate feedback, even when it is hard to hear. And it has been my experience that most people who publish in nature are pretty open to criticism. This is how science evolves. A good scientist doesn’t take offense at posts such as this one on RC.
4 January 2008 at 9:18 PM
(13) I liked your response, as it helps me understand the science better. I suspect that for >98% of journalists and the public, it would be interpreted as “it’s greek to me”. A translation (perhaps in the form of an executive summary) might look somewhat like:
Nature couples the surface, atmosphere, and GHG effects together. Any good model will take this interplay into effect. The single quoted sentence seems out of place with the rest of the paper.
I think we have to make it as easy as possible for journalists, and interested members of the public to gain at least an intuitive feeling for the systems we discuss. Otherwise, perhaps out of frustration at being able to do any better, they may resort to the gotcha game that we see so much in politics (and climate Change denial).
4 January 2008 at 9:59 PM
When I read a paper that has had nothing to do with a subject throughout and then brings up a hot-button issue in the conclusion, I find myself looking for some sort of quantitative analysis that supports what they’ve said. If I do not find that, I start to wonder about motivations. This is supposed to be science after all. If you aren’t going to provide quantitative support for a statement, why make it?
4 January 2008 at 11:06 PM
Unfortunately we don’t have the journal Nature here in the High Arctic, the introduction implies already well known heat transport mechanisms, such as more cyclones heading polewards, which was first introduced by models including AGHG’s. It is very much so, but not necessarily the only factor maintaining a warm Upper Thermal layer, now observed for many recent years by means of observing an increase in twilight brightness (during the long night, complementing the shorter perimeter radiosonde measurements ( www.eh2r.com scroll down for URL Y-V Ulluq Q Phenomena (March 22 2005) ) . I don’t know if the article deals extensively with moisture, which is becoming more and more important, particularly with strange phenomenon which I have not written about yet, of weak stars disappearing during the clear long night (having magnitudes greater than 4.2), all while having greater horizontal visibilities. Equally more common, moisture in the stratosphere. an indication of convection beyond tropopauses having weaker inversions. All an all, this article implies the correct reality, but is forgetful about past models projecting more advection by an increase in poleward cycclonic activity.
4 January 2008 at 11:25 PM
What is the structure of the circulation changes involved here? (So far I know that in response to global warming, storm tracks are supposed to shift poleward (would that mean greater north-south exchange at the highest latitudes, or would expected storm/wave activity changes negate that effect?), the Hadley cell is supposed to expand, the NAM index may increase.) (I looked at the figures and abstract of the paper but don’t have access to the full text right now. I’m not sure I understood what figure 3 was showing - I mean, time lag with respect to what? - were they looking at a number of events and computing the average of all events with time lags with respect to some aspect of the type of event?)
4 January 2008 at 11:58 PM
Lynn Vincentnathan (#22) wrote:
I believe you are right that journals should be more cautious and try to avoid publishing misleading information, particularly when it comes to climate change.
Lynn Vincentnathan (#22) wrote:
It is potentially harmful in that it provides skeptics and their audiences with justification for claiming that there exists a bias against their views and that nonobjective standards are given free-reign in climatology. No doubt they will make such claims regardless of whether they are true or not, but your principle and enunciation of it would mean that they actually have some justification for such claims. And this may persuade those who might otherwise be open to the science — but are at present uninformed. Likewise, to the extent that we might embrace such a principle, where errors are given a free ticket if done for the “right reason,” we would corrupt our ability to see things for what they are and respond accordingly. Identification must precede evaluation, always.
Lynn Vincentnathan (#22) wrote:
Granted, but when one does so, it must be clearly demarcated as an application of the cautionary principle, not simply as an unacknowledged attempt to warp the evidence towards conclusions that they do not in fact support in the way in which the author claims.
5 January 2008 at 12:15 AM
My understanding of the expectation of global warming is, of the zonally averaged latitude-height warming distribution, that the greatest warming would generally extend from the lower troposphere in the Arctic upward and equatorward to the tropical mid to upper troposphere; with the Arctic warming being greatest in Fall/Winter. From fig 1 - although the tropics are excluded - it is interesting to note that within the midlatitudes (30 to 60 deg), the meridional thermal gradient is enhanced at most levels in winter (with the opposite in the edge of the polar region). From that, I would guess the storm track position trend in winter is opposite that of the annual trend - and also, that in winter in the midlatitudes, both frequency and intensity of storms would increase (whereas the frequency of extratropical storms would decrease in the global annual average). Is that true?
5 January 2008 at 12:43 AM
Thanks for telling me about http://pubs.giss.nasa.gov/authors/gschmidt.html and those other web pages. The abstract of http://pubs.giss.nasa.gov/authors/gschmidt.html seems to be saying that we will not go extinct by the year 2100, but that we could be in trouble. From the anthropologists I get the idea that it doesn’t take That much of a problem for civilization to collapse or change in some really bad way. The whole 6 megabyte pdf is too long to get downloaded and read right now since it won’t fit on one microdisc.
5 January 2008 at 1:41 AM
Gavin said:
“There is no issue with this paper that would merit a comment to Nature, let alone having Nature actually publish it. This is simply a comment about loose language and the ensuing press confusion.”
I disagree that the paper is not worth a brief letter to Nature by you or someone else. Assuming the results of the GISS archive are borne out by other models, it is worth pointing out that GCMs predict, “A significant proportion of the observed temperature amplification…[is]…explained by mechanisms that induce warming above the lowermost part of the atmosphere.” [from their abstract]
And that models also project that, “…further substantial reduction of the summer ice-cover would strengthen these [snow and ice] feedbacks and they could become the dominant mechanism underlying a future Arctic temperature amplification.” Which appears to be borne out by recent data, if I understand Mark Serreze’s comment @9.
Not much can be done about the popular press getting the facts wrong, but Graverson et al (and presumably many other scientists) are probably not modellers and may be operating under the assumption that GCMs don’t capture this behaviour.
[Response: I think such a study would make an interesting paper, and the mechanisms of polar amplification even in the models have not been fully explored as yet (though a number of people are working on this). But the comment/reply route is not the place for follow-on work, rather it is supposed to address fundamental issues in a paper that might affect the conclusion - that doesn’t apply here. -gavin]
5 January 2008 at 2:18 AM
In the abstract for the following paper, a variety of elements thought to play a role in polar amplification as analyzed by climate modeling are mentioned — and the albedo effect is nowhere to be found:
Shortly afterwards, the authors state:
… citing some of the very same elements Graversen et al is concerned with — within the contexts of climate models. As with earlier studies, Miller et al argues that downward longwave flux plays an important role, one it gives centerstage, which is involved in a variety of positive feedback loops — which vary in strength and relative importance according to time and place (e.g., water vapor vs. cloud optical depth).
*
Finally, the authors state that their results are consistent with a polar amplification being driven by an increased water vapor, leading to a polar amplification which is strongest during the winter due to increases in open water and latent heat flux — as modeled:
I believe the albedo effect is most often mentioned as a cause of polar amplification because it is the easiest to understand. But judging from Miller et al (2007) at least and what it states with regard to literature, I find it difficult to believe that someone familiar with the literature would be unaware of other mechanisms being in play in model polar amplification.
5 January 2008 at 2:39 AM
wayne davidson (#33) wrote:
Below the tropopause at least (which is generally at pressures lower than 600 hPa, whereas this study focuses on 700 hPa or below), the following study would seem to support your view - although Siberia would appear to be an exception:
5 January 2008 at 7:19 AM
What is the difference between :-
(a) Global Warming directly causing meltdown in the Arctic and
(b) Climate Change (caused by Global Warming) causing changes in the Heat Transport system from the Tropics to the Arctic ?
Net difference ? Diddly squat in real terms. Direct, local Global Warming has been accentuated by extra Heat Transport.
So, the Meltdown is “worse than previously thought”, that is, there are more processes going on that simply local albedo effects from melting ice in the Arctic.
It’s misleading and plain unhelpful for the Media to push the idea that somehow changes in the Heat Transport process are not caused by Global Warming, that is, Man-Made Global Warming.
When I read this, I smelled the rat :-
=x=x=x=x=x=x=x=x=x=x=
http://cnews.canoe.ca/CNEWS/Science/2008/01/02/4749691-ap.html
“January 2, 2008
Natural causes as well as global warming may be causing Arctic thaw: study
By Seth Borenstein, THE ASSOCIATED PRESS
A new study suggests there’s more to the recent dramatic and alarming thawing of the Arctic region than can be explained by man-made global warming alone.
Nature may also be pushing the Arctic to the edge. A study being published in the journal Nature says there’s a natural cause that may account for much of the Arctic warming, which has melted sea ice, ice sheets and glaciers.
New research points a finger at a natural and cyclical increase in the amount of energy in the atmosphere that moves from south to north around the Arctic Circle.”
=x=x=x=x=x=x=x=x=x=x=
However, apart from skeptical/sceptical news streams, this “story” seems to have died a death - because the counter-argument is so obvious.
Thankfully this one can easily be made to go away. Not so the lack of balance at the BBC, who have published TWO “stories” on how compact fluorescents are bad for your health :-
http://news.bbc.co.uk/1/hi/health/7167860.stm
Low-energy bulbs ’cause migraine’
2 January 2008
http://news.bbc.co.uk/1/hi/health/7170246.stm
Low-energy bulbs ‘worsen rashes’
4 January 2008
which of course the Daily Telegraph put as :-
http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2008/01/05/eabulb105.xml
Low-energy bulbs ‘could cause skin cancer’
05/01/2008
5 January 2008 at 10:00 AM
“…claims to be a science writer and this article was in the Tuesday Science Times section. It is a fluff piece that reflects the intellectual laziness found in most of his writing, and about which he actually boasts in his NY Times personal page. Unfortunately, appearing in the Science Times, it will be taken seriously by many of the uninitiated. It is a mystery to me why the Times continues to sully its reputation with a guy like this.”
I thought RC did not allow ad-hom attacks. I suspect that if I had submitted something similar about a pro AGW writer, it would have been censored.
5 January 2008 at 10:25 AM
If models predict that Arctic temperatures will increase, most of all, way up in the
troposphere when business as usual CO2 levels are plugged in, and if Graversen’s paper
confirms that this is what has happened in recent decades, then are albedo changes
responsible, or is an increased transport of heat from the tropics responsible? The
answer to that simple science question is unclear. Mike Mc Cracken’s Post #13 is clear
on that.
RE: Press reports. The AP guy should have thought more and consulted more widely before
jumping to the conclusion that, if it were true, would make everyone happy, which is
that “its all a natural cycle”. The article could have been written more carefully.
RE: How to best deal with the press? The lessons seem to be that Graversen should have
checked out what the models predict, and that the referees should have caught the
offending paragraph.
meher
5 January 2008 at 10:30 AM
This seems to be simply an example of the final paragraph syndrome. You are trying to summarize the significance of your results in a few words and in a way that will get it past the gatekeepers at a high-profile journal, and it is easy to overreach. Sometimes it is caught before submission by the authors, or corrected in review, but I wouldn;’t be surprised if Nature sent the paper to measurement people rather than modelers, and it is easy to read over this kind of generalization without thinking about it too deeply.
Usually, this kind of thing doesn’t much matter, as knowledgeable readers will take this kind of unsupported overreaching with a grain of salt. However, given the controversy (in the popular media, if not in the scientific literature), it is easy for something like this to get overblown.
5 January 2008 at 1:00 PM
off topic: congrats to Gavin for being named one of the Guardians “50 People Who Could Save the Planet”
- back to my reading
5 January 2008 at 2:13 PM
I’m a Real-climate newbie and interested in learning about global warming. I wonder what the viability of this simplistic characterization would be about polar amplification. In winter time, there would be enhanced IR flux from greenhouse gases warming the poles relatively more so (given the stability and low surface temperatures) than at lower latitudes.
In summer, short-wave radiation becomes more important, though with reduced warming (locally over the ice areas) due to the ice albedo and latent heat of melting considerations. Would this help account for a smaller warming signal over the Greenland and Antarctic ice caps?
Are these factors reflected in the models?
5 January 2008 at 5:42 PM
Re 42. Steve, I regret the last sentence, which is something of a cheap shot that I should not have included. However, I think the rest is legitimate criticism of his writing. I sent Tierney a rather long email, outlining the difficulties climate scientists face in trying to communicate their findings to the public, and urging him to use his considerable talents to help.
5 January 2008 at 6:27 PM
Gavin, I’m trying to reconcile the model run during winter (and comment to #16) with the line in the study:
“amplification of the temperature trend during the dark months, November–February (Fig. 2). This amplification cannot be explained by snow-cover changes, as the albedo effect is practically absent during this dark period.”
Is this due to the latent heat “release” spoken of in the next few lines? From what I get, then, summer is the only time where the ice-albedo feedback is nearly non-existant due to phase change. The latent heat is released into the atmosphere during autumn and that causes amplification in the atmosphere?
[Response: Hmmm…. this isn’t something I’ve looked into in great depth, but my take would be that as temperatures increase, water vapour in air going poleward is higher and that leads to increased latent heat release when it condenses to make snow or rain. The ice-albedo feedback is most active in the spring and fall where it can make big differences to snow onset/melt dates. It is still active in the summer in the sea ice regions, but it doesn’t lead to large surface temperature changes because the presence (for the time being) of ice and open water means that any extra energy either goes into melting or into evaporation. But if readers have a more complete/better explanation I’m all ears… - gavin]
5 January 2008 at 7:48 PM
My opinion is that when publishing, there is always the temptation to go beyond the conclusions made evident by data and discuss intuition or perhaps even to “get revenge” on a particular article felt to have overstated its conclusions. This is the sort of stuff editors and reviewers really beat out of authors and researchers have learned to keep it out of manuscripts sent for peer review.
However, lately it seems that researchers are taking their “unpublishables” to the press.
These are the quotes that struck me as maybe a bit misleading in that the author is “speaking” for other scientists.
“It’s a remarkable result,” Graversen said. “I think nobody expected that.” and again “Retreating snow and ice cannot explain the vertical structure of the warming that we show,” Graversen said. “So snow and ice retreat is not as important as we previously thought.”
Is that what Graverson has done here? Or perhaps the reporter pestered it out of him?
5 January 2008 at 7:51 PM
Transient fluxes of heat and moisture (synopticians refer to them as real fluxes
) are generally much larger than climatological transports, especially in midlatitudes. In time, huge blasts of warm, humid air into the arctic from lower latitudes are largely counteracted by parallel surges of cold, dry air from the arctic to lower latitudes. The result is that local climatological values of heat flux observed over a month or season are at least an order of magnitude lower than the day-to-day local fluxes. Consequently, relatively slight variations in transient fluxes can lead to relatively large fluctuations in climatological fluxes.
The largest transports of heat in the lower troposphere are associated with intense mid-latitude cyclones and associated cross frontal circulations that are poorly resolved in GCM’s. It would not be surprising that GCM’s (and gridded global data sets dependent on spectral forecast models) underestimate the importance of these fluxes. Global models generally do not resolve the intensity of the mesoscale frontal and jet circulations that are responsible for local day-to-day variations in temperatures. The results of Graversen et al appear to be consistent with these limitations.
However, global-warming deniers would be ill-advised to use these limitations to support their thesis. If anything, GCM’s underestimating the power of transient fluxes would lead to underpredictions of arctic warming.
5 January 2008 at 8:34 PM
Is it possible to change the subject? This is urgent.
I just read a translation to Spanish, in La Tercera newspaper from Santiago, Chile, of a Dr David Whitehouse’s article, http://www.newstatesman.com/200712190004, arguing that Global warming has, temporarily or permanently, ceased, based on a fact that the “global temperature of 2007 is statistically the same as 2006 as well as every year since 2001”.
Where is Whitehouse getting the data from? Is it real?
For what I have seen, at least in Europe the 2006-2007 winter was the hottest in 150 years, I published a picture where you can see hundreds of people at a Spain’s beach tanning under the sun, days before 2006 Christmas.
Was 2007 the “hottest year in history” as predicted by professor Phil Jones, from the East Anglia University?
And finally who is Dr David Whitehouse? I could not find his bio.
5 January 2008 at 9:25 PM
RE #35 & 22, I do agree with you regarding the science contained in the various articles. Scientists cannot risk being the boy who called wolf. But they really should call wolf if it looks like one is coming. We know how that story ends…the wolf actually came and killed the villagers. Actually I think the villagers, and not the boy, are to blame.
I guess what I was getting at is that the reviewers and editors (if not the authors), should be more vigilant of wording and (unsupported) claims that might end up misleading people to believe that GW is not human-caused or is not happening, since there may be greater damage in this. Regular vigilance then should be given to claims that AGW is happening.
I know about peer-review. I’m dealing right now with making lots of corrections on an article I submitted, based on reviewers’ suggestions. Some minutely dealing with wording, and some pointing to my lack of evidence or support here and there, which happened when I tried to cut the paper down to the journal’s page limit, and cut out some references…so back go those references & I have to cut down the text somehow. I’m just thinking that the unsupported claim about models should never have passed peer-review (my reviewers would have picked up on it…they’re ruthless). The reviewers seemed to have done a sloppy job.
5 January 2008 at 9:30 PM
Hi, Gavin,
I read the Nature paper. It is an intersesting paper and I agree with you that if the authors had analyzed the CMIP3 output, it would be much better. I also don’t think it is right to say that in the CGCM models the ice (snow) albedo feedback is the main mechanism for polar amplification.
we [1] have recently published a paper and theoretically proved the feedback from heat transport greatly influence the vertical and meridional structure of global warming. It is important to point out the heat transport feedback does not have to warm the atmosphere only, it also can cause a larger surface warming by the concurrent other thermal-dynamic feedbacks.
[1] Ming Cai & Jianhua Lu (2007),
Dynamical greenhouse-plus feedback and polar warming amplification. Part II: meridional and vertical asymmetries of the global warming
Climate Dynamics Vol 29:375-391
doi 10.1007/s00382-007-0238-9
[Response: Jianhua, thanks for providing the reference for us and our readers. This site is at its best when fellow scientists come through and provide pertinent information and constructive feedback. - mike]
5 January 2008 at 9:40 PM
Jorge, no need to change the subject for that, it’s a common story.
http://scienceblogs.com/stoat/2007/05/the_significance_of_5_year_tre.php#
http://scienceblogs.com/deltoid/2007/12/a_picture_is_worth_a_thousand_2.php
http://gristmill.grist.org/story/2006/11/4/175028/329
http://tamino.wordpress.com/2007/08/31/garbage-is-forever/#comment-11588
5 January 2008 at 9:43 PM
Jorge Ianiszewski (51) wrote:
Oh, that article:
Has global warming stopped?
David Whitehouse
Published 19 December 2007
“Where is Whitehouse getting his data from?”
Haven’t a clue. Doesn’t seem too keen to share it with us, either.
“Is it real?”
Well, you could try looking up the charts.
But don’t worry, I will give you one with both the GISTEMP and HadCRU — although I should point out that the chart I am giving doesn’t end with the last few months of this year.
Here you go:
GISTEMP (NASA GISS) / HadCru (Hadley MET)
http://tamino.files.wordpress.com/2007/08/t2000.jpg
Now here is the webpage:
Garbage is Forever
August 31, 2007
http://tamino.wordpress.com/2007/08/31/garbage-is-forever/
GISTEMP is rising at a rate of 0.28 C per decade, plus or minus 0.19 C per decade. HadCRU is rising at the rate of 0.18 C per decade - plus or minus 0.16 C per decade. It doesn’t look to me like there is the exact cancelation that Whitehouse seems to think there is. As such, it is actually higher than the linear trend you get by going 1975 to present for NASA GISS (0.18+/-0.03 C/decade), but slightly lower than what you get from HadCRU for the same period (0.19+/-0.03 C/decade). I would check out the webpage — to learn a little about what gimmicks people can use when they want to lie with statistics, incidentally.
Why the difference between GISTEMP and HadCRU? Mostly because GISTEMP includes the stuff above the Arctic circle but HadCRU doesn’t. The stuff that gets lopped off by HadCRU is where the greatest warming is taking place.
The fact that the greatest warming takes place up there is called “polar amplification.” Why does it take place? Well, that actually brings us back pretty darn close to the topic of this post….
You might want to check out my comment 39, though, and maybe even look up the article it references.
Jorge Ianiszewski (51) wrote:
You might want to read the bottom of the page you are linking to:
5 January 2008 at 10:18 PM
Jorge Ianiszewski, re: 51
Why on Earth do you want to go to the effort of translating that drivel. Whitehouse is yet another non-climate scientist who doesn’t understand climate. Yes, the current solar cycle started late. Yes, it looks like it might be a weak one as far as solar activity is concerned. It might even wind up affecting climate somewhat. However, any hiatus in solar activity will end–perhaps in a few years, perhaps a decade or two, perhaps even after 80 years as with the Maunder Minimum. And when it ends, the CO2 will still be there, and it will still be trapping heat, and things will go right on heating up for HUNDREDS of years. Only if we get a hiatus from warming, we will likely lose focus on greenhouse gasses and dump even more CO2 into the atmosphere, making the problem even worse.
As to his statistical arguments, he should be ashamed of himself. The trend is still up–and the only way to avoid that conclusion is to cherrypick your starting point.
5 January 2008 at 11:34 PM
But, don’t let us get sidetracked, right? It’s so easy to do.
6 January 2008 at 12:27 AM
Gavin;
re your response to 48.
One of the neat things about RC is the interdisciplanary weath of things that you would never encounter just reading Science ,Nature and JGR or Eos. Somewhere in the links above one learns that arctic refraction effects can lead to distorted images of the sun being visible 5 degrees below the horizon. If the red shift continues into the IR, can significant amounts of atmospheric radiation be refractively channeled across the terminator into the arctic winter dark , effectively bringing forward the edgewise onset of daylight warming before the arctic spring dawns? This is a shot in the dark question, and i apologize if it is quantitatively irrelevant, because I have no notion of atmospheric dispersion in the IR.
6 January 2008 at 7:25 AM
Russell, The effect seems to be due to temperature inversions, with greater refraction occurring in the layer of cold dense air, and less in the air above it. The images on the website certainly appear to suggest that blue light will be affected more than blue–consistent with rayleigh scattering. Wouldn’t this suggest that the effect will be less for IR than for shorter wavelengths. So, we’ll see it before it warms us. Also, remember that the Sun is not too bright in the IR.
Some absolutely awesome stuff on that site, though–many thanks to Wayne Davidson for the reference, which I reproduce here just in case anybody missed it:
www.eh2r.com
Don’t miss the sunset pictures–one of the best blue-flash photos I’ve seen.
6 January 2008 at 9:21 AM
RE #51, here is a way of conceptualizing denialist arguments that have been roundly rebutted by science time and time again: ZOMBIE LIES. One aspect is, the conventional wisdom is that the more wrong you are, the more credibility your opinion has about anything having to do with ___ (insert AGW). This might explain why denialist arguments never die, no matter how dead science seems to kill them.
I saw a discussion of this in a Huffington Post article (though it was on a different topic): http://www.huffingtonpost.com/arianna-huffington/i-am-conventional-wisdom_b_78958.html
6 January 2008 at 10:11 AM
Here’s another source: http://mintaka.sdsu.edu/GF/explain/explain.html
“…the red image of the Sun (or of some miraged part of it) sets or disappears first, followed by yellow, green, blue and violet….”
Mike, I hope you can say more about the two papers (Cai and Lu, Lu and Cai, they are parts I and II) on theory once you’ve read them.
Found the abstract: http://www.ingentaconnect.com/content/klu/382/2007/00000029/00000004/00000238
6 January 2008 at 12:25 PM
Perhaps you could add the missing verbage that is indicated by the four periods between “feedbacks. ….Much” in your initial comments for the benefit of those of us who do not have a subscription to Nature. I for one tend to become concerned when one questions another’s comment or point of view without citing their comment or point of view in its entirety.
Thanks.
6 January 2008 at 2:33 PM
It changes nothing that Gavin et al. have commented on.
6 January 2008 at 3:06 PM
Unrelated to this article, but now that it’s 2008, we’ve had exactly 10 years of “no warming since 1998″. Does someone want to write up a quick analysis of exactly how much warming we have had since 1998, and how well that correlates to model predictions? (From my calculations, roughly .2C - and since 1999 we’ve had almost .3C!)
6 January 2008 at 3:24 PM
Probably the wrong place but, when is someone going to address the NASA report on sun spots and the prediction of 20 to 30 years of a colder planet? I think they are saying that a whole bunch of hot air will be leaving the web very soon.
[Response: While NASA does forecast sunspot and solar activity, there are no NASA predictions of 20 years of a colder planet. Please look into your sources a little more carefully. - gavin ]
6 January 2008 at 3:37 PM
Ray Ladbury> …even after 80 years as with the Maunder Minimum. And when it ends, the CO2 will still be there, and it will still be trapping heat, and things will go right on heating up for HUNDREDS of years.
I doubt that you can support that statement unless you are just talking about a small fraction of present CO2. The half-life of CO2 in the atmosphere is much less than 80 years.
6 January 2008 at 4:09 PM
re: #65 pbview, yes wrong place, but…
This is a common meme running around right now, so we can guess which blogs pbview relies on. Some of it seems to originate from John L. Casey’s “press release” at SSRC, amplified by the usual blogospheric behavior:
Google: john casey changes sun’s surface next climate change
I ran into this over at Jennifer marohasy’s blog, and said:
“SSRC: you have to be kidding me: http://spaceandscience.net/ looks impressive! until you realize that:
John L. Casey looks like a one-man-band apparently pushing consulting services based on some climate theory he has.
His address is 4700 Millenia Blvd #175 Orlando FL, and if you Google that, you will discover an amazing number of companies that seem to be located in that office suite.
That’s because the suite in this this impressive building isn’t even Casey’s own office, but is occupied by: Intelligent Office :
“Intelligent Office locates your business in one of the best buildings in town. You’ll have a prestigious business address for your mail, your stationery and your advertising, as well as an impressive place to meet your clients. Your address with us will have your company’s name, not ours, and if you work from home, this is a great way to protect your privacy.”
There is nothing obvious in Casey’s background to establish any particular expertise in climate science, no obvious presence in Google Scholar, and nothing before a recent press release. The info sounds like yet another “I’ve discovered cycles” thing, which happens all the time. Of course it could also be another “Carbon dioxide production by benthic bacteria..” scam, albeit on a much smaller scale (and if it is, I apologize in advance if that helps ruin somebody’s joke.) The website is 2 months’ old.
Casey’s “press release” isn’t even up to Rob Ferguson’s standards. Casey “confirms” 18-month-old research from NASA, and has comments that certainly sound like Casey being interviewed by his own sock puppets.
The NASA item referenced by Casey is about cycle 25; the one mentioned by another poster James Mayeau is about a different 200-year cycle [which is usually called the de Vries or Suess Cycle, although Casey talks like he found it himself]. In neither case was NASA telling people to expect another Maunder Minimum within the next decade or two. [Personally, I’d be delighted if the Sun cooled back like that, but it wouldn’t help very much.]
4) This is another instance of standard arguments from:
http://www.skepticalscience.com/argument.php
1 sun
16 newice
41 solarcycle
or http://en.wikipedia.org/wiki/Solar_variation (see first chart especially; as usual, Wikipedia isn’t an authoritative reference, just a good start).
All this stuff has been covered at RC many a time.
6 January 2008 at 5:02 PM
Speaking to the question of anthropoligical effects speeding GW over the arctic.
Am I mistaken in my belief that (among other changes) we need to reduce high latitude air traffic during the winter months, when there is little sunlight to reflect and cloud cover tends to trap heat, while possibly increasing it during the summer to increase albedo over the region?
6 January 2008 at 5:15 PM
#58 Russell, I gave this IR boost idea some thought, it is a novel idea, and Ray got it right in #59, I expand on his explanation a little bit. Refraction occurs in all visible and invisible wavelengths. Whereas in visible light, the index of refraction for red is somewhat lesser than blue, this is clearly explained on Dr Andrew Young’s site:
http://mintaka.sdsu.edu/GF/explain/simulations/std/rims.html
Where blue is displaced higher above the horizon than red, creating the 3 main sun colours over the horizon to get vertically displaced. Often misunderstood as Rayleigh scattering, refraction effects are numerous including the creation of 2 to 7 sun images on the horizon:
http://www.eh2r.com/mp/data_2003.html
These extra suns are created in ducts, where the entire sun disk is trapped and compressed in
a thermal layer causing total internal refraction. These ducts can be short, a few Kilometers
or long a thousands of Kilometers, and may in effect cause the sun to disappear in mid air, ie the not so famous Wegener blank strip.
Refraction distributes EM from a point source, in this case the sun, not so hot in the IR but quite
hot in UV. Where Rayleigh scattering is quite effective, even so, UV photons have been measured 2 or 3 weeks before the rise of the sun during the long arctic night at twilight (take my word for this, no reference, guys in Antarctica may confirm this). if there is any heat effects at all it would be in the blue and beyond wavelengths, don’t expect it to be huge, but it may be an important extra forcing component especially for the Polar or Antarctic long nights.
6 January 2008 at 5:54 PM
Steve Reynolds Says:… The half-life of CO2 in the atmosphere is …
Citation please? If you’ve come up with your own unique number from personal experiments, show us your method. Else your scientific cite?
6 January 2008 at 6:13 PM
Steve Reynolds said: “The half-life of CO2 in the atmosphere is much less than 80 years.”
Actually it’s over a century. You should read Spencer Weart’s history–particularly:
http://www.aip.org/history/climate/Revelle.htm
CO2 is a gift that keeps on giving. Keep in mind that the biosphere does not sequester CO2 indefinitely. In fact, more plantlife can wind up giving rise to more CH4, which has a much higher warming “bump” before it too becomes CO2. Planting trees is at most a delay, not a solution. And the oceans are already diminishing in their ability to absorb carbon.
6 January 2008 at 6:13 PM
Re #68 (Jerry Toman)”Am I mistaken in my belief that (among other changes) we need to reduce high latitude air traffic during the winter months, when there is little sunlight to reflect and cloud cover tends to trap heat, while possibly increasing it during the summer to increase albedo over the region?”
I would think yes, with regard to the second part of your belief. Air traffic anywhere, anytime pumps more CO2 into the atmosphere, and that will be around far longer than, and so, I would think, will greatly outweigh, any possible effect of an increase in albedo so far as warming is concerned. A large part of what leaves the atmosphere will add to ocean acidification. If you’re serious about slowing AGW, don’t fly unless you absolutely have to.
6 January 2008 at 6:15 PM
Re 59
Thanks Ray. I was not thinking of solar IR radiation, but the fact that the atmospheric 5 to 15 micron emission may be channeled up and over the apparent horizon just as the solar image is even though it is out of the line of sight.
My apologies for making the analogy mistakable for a long wave green flash- I’m wondering instead about the IR dispersion of the atmosphere considered as a pressure gradiated GRIN lens in the vibrational line regime.
6 January 2008 at 6:16 PM
Dylan, re #64. Actually, no, we’ve had 10 years of misinformed denialists claiming there has been no warming since 1998. 1998 was a big year for El Nino, so it is an outlier. You could look this stuff up on this site if your were so inclined.
6 January 2008 at 6:36 PM
Steve Reynolds writes:
[[The half-life of CO2 in the atmosphere is much less than 80 years.]]
Try 200.
6 January 2008 at 6:56 PM
The problem really seems to be with the AP reporter’s interpretation of the paper. What exactly does the phrase “natural and cyclic behavior” mean? The implication is that natural and cyclic behavior does not involve global warming.
However, if you have an increase in poleward heat transport and no cooling in the equatorial zone, that can’t be interpreted as anything but global warming, just based on simple conservation of energy arguments. (Such conservation of energy arguments don’t apply to local albedo changes - but albedo is responsive to increased heat transport… in any case, scraping snow off the ground in the Arctic in the summer is unlikely to lead to a runaway albedo feedback effect…)
The statement in the AP article that “Scientists are trying to figure out why the Arctic is warming and melting faster than computer models predict” is worth looking into, however. Perhaps comment #50 above gives some explanation:
“If anything, GCM’s underestimating the power of transient fluxes would lead to underpredictions of arctic warming.”
There’s also another route to warm the arctic ocean and thin the perennial sea ice, and that is oceanic heat transport. Trying to divide up the heat transport between oceanic and atmospheric routes appears non-trivial because there is a constant heat exchange between oceans and atmosphere that is related to things like wind speed and the amount of ice insulation. Furthermore, the ocean is slow to respond to forcings compared to the atmosphere. By the way, here is a NASA press release on changes Arctic oceanic circulation (Nov 2007) that seems to have some of the same problems that the AP article does! The press release states that “The results suggest not all the large changes seen in Arctic climate in recent years are a result of long-term trends associated with global warming.”
Again, the impression here is that the warming can be explained by ‘natural causes’ - but really, the article is about the switch from counterclockwise to a clockwise rotation. A better way of putting it would be that “natural cyclical changes are superimposed on a general warming trend - the outcomes are going to be complicated.”
In the south, it also appears that melting in the West Antarctic has been accelerating, also according to NASA. Now, if the Arctic and Antarctic are melting, and the equator is not cooling, then there is no way that can be a ‘natural and cyclic process’ not related to global warming!
The situation is complicated, but that’s no excuse for simplistic reporting. For example, some recent reports indicate that wind forcing of ice out of the Arctic Ocean is a major factor in the large open-water regions in the Arctic this past summer. However, that doesn’t mean a ‘natural cause’. Thick, broad sheets of perennial ice are resistant to wind forcing - but as the ice thins due to global warming, and sheets break up into fleets of icebergs, the sensitivity of ice masses to wind forcing increases.
Anyone who fundamentally doubts that a small initial forcing can have a large effect on a system, out of all proportion to the initial forcing, might want to take a look at this: All fall down.
Finally, the real blunder in the AP story is this:
“The Nature study suggests there’s more behind it than global warming because the air a couple miles above the ground is warming more than calculated by the climate models.”
That statement assumes that climate models are absolutely correct on global warming, so that if something happens that’s unpredicted, it must not be global warming, but rather a ‘natural effect’! Huh? That’s on top of the general theme here, the lack of references to actual climate model results in the paper.
In that regard, reporters covering climate science might want to look at the following course lecture page, and see if they can answer the questions at the bottom, just to make sure they don’t make any more such embarrassing blunders (which, to be fair, are a more-or-less unavoidable side effect of scientific inquiry).
http://www.env.leeds.ac.uk/envi2150/oldnotes/lecture2/lecture2.html
6 January 2008 at 6:56 PM
#73 Russell, If there is a significant source of IR which may enter a duct, I don’t see why it can’t travel
the same way as any visible or invisible light, its a question of direction, how would this IR have momentum such as light from a point source?
6 January 2008 at 7:14 PM
(Note about the spam filter: It hadn’t occurred to me and I hadn’t seen it noted that the filter catches more than just intact words; e.g. in the case of this post it caught speCIA-LISist sans hyphen.)
Re #13 response: At this point, it seems fair to say that all climate-related articles in Nature and Science are for public consumption, whether the authors intend it that way or not. There’s nothing about the problem that couldn’t have been caught and fixed by a non-specia-list editor. The substantive issue of the comparison with the model results aside, the phrasing was still very clumsy.
That said, kudos to whichever one of the authors it was that came up with the idea of using that data source. It sounds as if it will be very useful for more than just this paper.
Re #23: Er, Joe, how about an English major instead?
6 January 2008 at 7:26 PM
Re #71 and others: No need to look elsewhere for a good discussion of CO2 persistence. It seems to me that use of the term “half life” in this context, even if it can be defined, is inappropriate, since the decay is very much non-exponential.
6 January 2008 at 8:38 PM
Ray Ladbury> Actually it’s over a century. You should read Spencer Weart’s history.
How about an actual AGU paper by Moore and Braswell (1994)
From their abstract:
We note that the single half-life concept focuses upon the early decline of CO2 under a cutoff/decay scenario. If one assumes a terrestrial biosphere with a fertilization flux, then our best estimate is that the single half-life for excess CO2 lies within the range of 19 to 49 years, with a reasonable average being 31 years.
As they say, decline slows after the initial reduction, but 1/2 is likely gone in about 30 years.
6 January 2008 at 9:39 PM
re 69;
I have some idea of how to relate dispersion to wavelength in solids where the Kramers -Croneig & Clausius-Mosetti relations hold, but lack any intuitive connection between waveguide theory that presumes a big step function between propagating and reflecting mediqa and gas channels , where the RI and , I assume , the dispersion is ~threeordersof magnitude smaller. For a lossless medium it just scales with distance, so 1000 kilometer pathlength may be realistic,but I’m still clueless as to the scattering freepath - how reflective is the ionosphere at low angles at say 10 microns ?
6 January 2008 at 9:54 PM
Steve, I am familiar with the Moore and Braswell paper.
First, as I said before, the increased plant growth at most delays the issue, as plants eventually die and the CO2 goes back into the air. Neglecting this delay, the time constant they come up with is 92 years. Also, if you have less sun due to a sunspot minimum, you’ll have less plant growth.
Second, as David Archer points out in the piece S. Molnar cites (thanks, I’d lost track of where I’d read this), a mean lifetime of several hundred years is more reasonable, but some of the increase relaxes only on geological scales.
To assert that we’ll all be OK in a hundred years or so goes beyond optimism right into delusion.
6 January 2008 at 10:31 PM
# 81, Russell, I am not familiar with Ionospheric refraction, these ducts exist at 10 to 500 meters above sea level,in the troposphere, right below manly isothermal layers within steep inversions.
6 January 2008 at 10:44 PM
Re #74: Ray, I still see the “no warming since 1998″ line spouted out here and there. A quick write up and a nice graph showing that, even with 1998 being such an unusually warm year, the average temperature has still risen .2 degrees in the 10 years from 1998-2007, would be a nice retort to such posters.
6 January 2008 at 10:45 PM
A question tangentially on topic: If a major source of the atmospheric transport is water vapor condensing to “clouds and snow” in the mid-upper Arctic troposphere, why doesn’t the snow, etc. mitigate the “snow melt” and in turn maybe the ice recession?
6 January 2008 at 10:48 PM
ps I omitted (though it may be obvious anyway) that the release of the latent heat in the condensation is billed as a major source of the troposheric temperature rise….
7 January 2008 at 12:01 AM
Dylan, several above have pointed to various answers to ’since 1998′
Try again: http://tamino.wordpress.com/2007/08/31/garbage-is-forever/
—–
Rod, re “why doesn’t …” consider the quantities involved ….
There’s more snowfall at higher elevations in Greenland, but the total mass balance is still negative, for example.
7 January 2008 at 12:21 AM
It is a joy to see Gavin’s and whole team’s work recognised by the Guardian as part the group of 50 people who can save the planet. In the course of writing our book, Apollo’s Fire:Igniting America’s Clean Energy Economy, we kept running into people on the cutting edge of technology who depended upon Real Climate both for baseline info and interpretation from an objective source. When people in the scientific community step up to the plate and help the broader community really understand the science involved, it is of inestimable value to us who are trying to move the ball in Congress. Great Work!
[Response: Thanks for the kind words Congressman. It was a bit disappointing to see Bjorn Lomborg listed there, since for example his latest book “Cool It” truly misrepresents the science, as well as the economics, of the issue (more on that soon). However, we appreciate the recognition. Keep up the great work yourself! - mike]
7 January 2008 at 12:47 AM
The real culprit in this story seems to me to be Borenstein’s exceedingly sloppy AP story, perhaps nudged along by something badly phrased said by Graverson in the interview. The actual statement in the article, which Gavin fairly calls into question, is pretty ambiguous, which is its main fault. I can see a reading of their prose that is fairly innocuous; when I talked to one of the authors in Stockholm earlier this fall, he expressed a clear interest in looking at the AR4 archive to see if the effect is there. That suggests strongly that there wasn’t any a priori assumption that models are wrong about this.
Regarding the ambiguity of the phrasing, remember these are Swedes writing in English, and while Swedes are outstanding linguists (coming from a small country where hardly anybody outside speaks their language) nuances are the hardest thing to translate. On top of that, Nature has its own copy-editors who in my experience sometimes change the meaning in their efforts to “improve” the understandability of the prose. Authors get to see this, but they have to flag it and complain if something goes awry. I’ve asked one of the authors I know to comment on their intent here. They’re good scientists, and I’m sure they did not intend any harm.
Now, let me emphasize the really remarkable thing about this result, if it holds up. The neat thing is that the heat flux increases even though (through polar amplification) the temperature gradient is weakening. My first reaction was “aha, latent heat!” but Michael Tjernström (back in September) told me they looked at that, and it’s mostly sensible heat increases doing the trick. That means there is some really interesting dynamics going on — some effect of changes in horizontal shear, maybe some feedback from lapse rate changes, maybe something associated with poleward migration of storm tracks. I really hope this result holds up, since if it does that’s more cool work to be done by dynamicists in understanding what is going on. Think of the possible repercussions for the unsolved problem of maintaining an ice-free state in the Cretaceous!
[Response: I would second this. There may be something very interesting to learn in investigating the AR4/CMIP3 multi-model ensemble to see whether or not this observation holds up in current generation models and, if not, what features in the meridional heat transport budget appear to differ. As for unsolved problems such as the “equable climate” problem (i.e., the ice-free poles and reduced meridional temperature gradient in some deep time paleoclimate periods), there are some intriguing alternative explanations already out there, such as (first posed by Kerry Emanuel) feedbacks between warming tropics, tropical cyclone activity, and associated upper ocean mixing, see e.g. Sriver and Huber (Nature, 2007) - mike]
7 January 2008 at 1:45 AM
Needless to say, I am extremely pleased and impressed that congressman Jay Inslee checked in to congratulate Gavin on his well deserved recognition. If members of Congress are checking in on Real Climate, perhaps there is some hope that this country might develop some policies necessary to deal with this problem!
7 January 2008 at 2:38 AM
#83
Got ,Wayne- the question is one of the acceptance angle for emitted IR ray paths refracted from under the horizon through a near surface mirage inversion- So I can assume a few % density contrast per 10 Kelvins.
7 January 2008 at 2:59 AM
#90 raypierre,
given that statement, what would you say about my comment #48 (And gavin’s response?). Gavin’s explanation makes sense, and would probably be a quick hypothesis I would give if my professor asked me. I would not think that sensible heat is sufficiently strong here, but this is interesting.
7 January 2008 at 5:02 AM
Talking about high profile papers, has anyone got anything on the alleged prediction by the Russian academy of science that solar cycles 24 and 25 will take us straight back into a little ice age, and there will be no/ very few sunspots? It looks very dodgy, but of course denialists are starting to use it as an excuse not to do anything, never mind the small problem of ocean acidification.
7 January 2008 at 5:04 AM
Re: #51
Where is Whitehouse getting the data from? Is it real?
From the Hadley/CRU surface temperature record. The Hadley surface temperature anomalies for this century so far (i.e. 2001-2007) are as follows: 0.40, 0.46, 0.47, 0.45, 0.48, 0.42, 0.41 (up to Nov).
Whitehouse (whoever he is) therefore appears to be correct in his statement regarding the lack of significant difference between the years, though he may be a bit premature in declaring that the “warming is over”.
Was 2007 the “hottest year in history” as predicted by professor Phil Jones, from the East Anglia University?
The prediction was that there was a 60% chance that the 1998 record of 0.52 deg C would be exceeded in 2007. The actual prediction was for an anomaly of 0.54 deg C (0.38-0.70; 95% CI). If they’re lucky the final value for the year will just fall inside the low end of their specified 95% confidence range. We can assume, therefore, that Hadley thought there was something less than a 5% (nearer 2.5%) probability that the global temperature would be as low as it actually is.
7 January 2008 at 5:59 AM
#90: “..poleward migration of storm tracks …”
Everybody is obsessed by storms. They are spectacular, do a lot of damage and transport plenty of energy. Good reasons.
I am obsessed by a semi-permanent blocking high that seems to steer those storms over much of the north. Like hurricanes, storms do not have a will of their own but move in paths determined by their surroundings. In America for some reason the jet stream is frequently mentioned, in Europe very seldom, if ever.
There is a nearly permanent area of high pressure over Siberia and Central Asia. For some reason last summer this fair weather expanded or moved to cover much of the Arctic, and was instrumental in the exceptional sea ice melting (with other factors). Most of time the western edge of that same blocking high determines if the Atlantic depressions hit Europe or pass it by on a more northerly track.
How far west the high extends and the shape of it largely determines the type of weather in Europe. Some ten years ago there was an impressive display. A train of rather compact Atlantic depressions passed over France, proceeded the length of a hot Mediterranean picking up humidity, hit a stonewall north of Turkey and was forced on an unusual path towards northwest. The result was a week of torrential rains in southern Scandinavia and extensive flood damage.
Why is this high there in the first place? I do not know, maybe something to do also with plain geography. The Americas have the Rockies and Andes, running north to south. Eurasia has mountain ranges running from east to west, China to Spain. Features that reach to mid-tropospheric heights.
Warming surely affects everyday weather. Still, IMHO it is simply not knowable what the exact impacts are on a daily and local basis. Maybe changes of a semi-permanent, large and influential feature could be more tractable. Also even a slight expansion to the west would steer more Atlantic storms (and their energy) to the Arctic - a possible feedback mechanism.
Just musings of an amateur, of course …
7 January 2008 at 8:59 AM
A few people have belittled the topic of this post:
http://www.nationalpost.com/opinion/columnists/story.html?id=1987d3e5-0c53-46fb-a01a-74bb49718c8e&k=97665
A national newspaper, a Conservative bent, no class nor scruples, a readership of 100,000s. That’s why its important.
7 January 2008 at 9:44 AM
> latent heat … sensible heat …?
Speculating from hang-gliding experience, I looked up ‘orographic’ and ‘Greenland’ and found, for example, this discussion:
http://www.nrlmry.navy.mil/~doyle/pubs/Doyle_Shapiro_1999.pdf
——brief excerpt——-
… low-level jet streams … form in stratified flow downstream of the vertex of large elliptical barriers such as the southern tip of Greenland, hereafter referred to as “tip jets”. The tip jet dynamics are governed by conservation of Bernouli function as parcels accelerate down the pressure gradient during orographic descent. In some circumstances, the Greenland tip jet is influenced by baroclinic effects such as differential horizontal (cross-stream) thermal advection and/or vertical shear. In contrast, in the barotropic situation upstream flow is diverted around and over the obstacle into laminar (Bernouli conservation) and turbulent (Bernouli deficit) regimes, respectively. In both situations, a downstream geostrophic balance is achieved, characterized by baroclinicity and vertical shear associated with the surface-based tip-jet front. … Enhanced surface-based forcing of the ocean circulation occurs in the region of the tip jet core through large air-sea energy exchange (upward surface-heat fluxes > 800 W/m-2), and at the tip jet flank ….
——end excerpt——-
800 watts per square meter heat flux is interesting, isn’t it?
7 January 2008 at 11:35 AM
CAN GAVIN SAVE THE WORLD?
He’s on a list of 50 possibles:
http://dotearth.blogs.nytimes.com/2008/01/06/the-guardians-50-people-who-could-save-the-planet/
[Response: You don’t want to believe everything you read in the newspapers…. - gavin]
[Response: Well, when you read what they wrote it was really “RealClimate” they were awarding this too. Sort of like IPCC being awarded a Nobel Prize. Of course, they had to choose a “person” in this case. Gavin is a co-founder, and has been by far the most active of us over the past couple years, so the best choice in that regard. But the others of us who co-founded and/or contribute regularly to the site can take some satisfication for this recognition, even if we have to share it w/ Lomborg
- mike]
7 January 2008 at 12:32 PM
re 97
While this paper notes the applicability of the effect to other locations (e.g., Antarctica) it neglects to note that Greenland is unique in that it has two tips generating vortices. I suppose this was less of an issue then, as the sea ice reduced heat exchange between the Arctic Ocean and the atmosphere. Now that there is less sea ice, the heat fluxes associated with the northern vortex are - larger..
7 January 2008 at 12:52 PM
Re: 98
The Guardian fails to fully realize that the description of a problem, does not directly equate to the solution of that same problem. Their choice of using the phrase “save the planet” implies we are on the “solution side of the problem”, instead of the “description side of the problem”.
If we use the “savior” term now, what will be left for later? “Grand exalted pooba”
7 January 2008 at 1:44 PM
I imagine you’re talking about that piece put up by ONE MEMBER of the Russian Academy of Science???
7 January 2008 at 2:41 PM
> 97
Yep, that was just a random grab by an uneducated reader to note there’s work available. Interesting that the Navy was looking into this issue a decade or more ago. I’m sure there’s more, don’t consider that one paper a best answer, just a possible clu