Regular readers may recall some of the posts here, here, here, and here, where the sea ice data presented by NSIDC and by Cryosphere today were brought into question. We finally have an end to this year’s arctic melt season, and our regular contributor on sea-ice, Steven Goddard, was able to ask Dr. Walt Meier, who operates the National Snow and Ice Data Center 10 questions, and they are presented here for you. I have had correspondence with Dr. Meier and found him straightforward and amiable. If only other scientists were so gracious with questions from the public. – Anthony
Questions from Steven Goddard:
Dr. Walt Meier from The US National Snow and Ice Data Center (NSIDC) has graciously agreed to answer 10 of my favorite Arctic questions. His much appreciated responses below are complete and unedited.
1. Many GISS stations north of 60 latitude show temperatures 70 years ago being nearly as warm as today. This pattern is seen from Coppermine, Canada (115W) all the way east to Dzardzan, Siberia (124E.) The 30 year satellite record seems to correspond to a period of warming, quite similar to a GISS reported period in the 1920s and 1930s. Is it possible that Arctic temperatures are cyclical rather than on a linear upwards trend?
No. Analysis of the temperatures does not support a cyclic explanation for the recent warming. The warming during the 1920s and 1930s was more regional in nature and focused on the Atlantic side of the Arctic (though there was warming in some other regions as well) and was most pronounced during winter. In contrast, the current warming is observed over almost the entire Arctic and is seen in all seasons. Another thing that is clear is that, the warming during the 1920s and 1930s was limited to the Arctic and lower latitude temperatures were not unusually warm. The recent warming in the Arctic, though amplified there, is part of a global trend where temperatures are rising in most regions of the earth. There are always natural variations in climate but the current warming in the Arctic is not explained by such variations.
2. The US Weather Bureau wrote a 1922 article describing drastic Arctic warming and ice loss. In that article, the author wrote that waters around Spitzbergen warmed 12C over just a few years and that ships were able to sail in open waters north of 81N. This agrees with the GISS record, which would seem to imply that the Arctic can and does experience significant warming unrelated to CO2. Do you believe that what we are seeing now is different from that event, and why?
Yes. The current warming is different from the conditions described in the article. The Weather Bureau article is specifically discussing the North Atlantic region around Spitsbergen, not the Arctic as a whole. The Arctic has historically shown regional variations in climate, with one region warmer than normal while another region was cooler, and then after a while flipping to the opposite conditions. As discussed above, the current warming is different in nature; it is pan-Arctic and is part of widespread warming over most of the earth.
3. A number of prominent papers, including one from Dr. James Hansen in 2003, describe the important role of man-made soot in Arctic melt and warming. Some have hypothesized that the majority of melt and warming is due to soot. How is this issue addressed by NSIDC?
NSIDC does not have any scientists who currently study the effect of soot on melt and warming. Soot, dust and other pollution can enhance melting by lower the albedo (reflectance of solar energy). However, it is not clear that soot has increased significantly in the Arctic. Russia is a major source of soot in the Arctic and Russian soot declined dramatically after the break-up of the former Soviet Union – just as sea ice decline was starting to accelerate. Furthermore, while soot on the snow/ice surface will enhance melt, soot and other aerosols in the atmosphere have a cooling effect that would slow melt. Thus, the effect of soot, while it may contribute in some way, cannot explain the dramatic rate of warming and melt seen in the Arctic seen over the past 30 years.
4. The NSIDC Sea Ice News and Analysis May 2008 report seems to have forecast more ice loss than has actually occurred, including forecasts of a possible “ice-free North Pole.” Please comment on this?
What NSIDC provided in its May report was “a simple estimate of the likelihood of breaking last year’s September record.” This gave an average estimate that was below 2007, but included a range that included a possibility of being above 2007. With the melt season in the Arctic ending for the year, the actual 2008 minimum is near the high end of this range. In its June report, NSIDC further commented on its minimum estimate by stating that much of the thin ice that usually melts in summer was much farther north than normal and thus would be less likely to melt.
In the May report, NSIDC also quoted a colleague, Sheldon Drobot at the University of Colorado, who used a more sophisticated forecast model to estimate a 59% chance of setting a new record low – far from a sure-thing. NSIDC also quoted colleague Ron Lindsey at the University of Washington, who used a physical model to estimate “a very low, but not extreme [i.e., not record-breaking], sea ice minimum.” He also made an important point, cautioning that “that sea ice conditions are now changing so rapidly that predictions based on relationships developed from the past 50 years of data may no longer apply.” Thus NSIDC’s report was a balanced assessment of the possibility of setting a new record, taking account of different methods and recognizing the uncertainty inherent any seasonal forecast, especially under conditions that had not been seen before.
For the first time in our records, the North Pole was covered by seasonal ice (i.e., ice that grew since the end of the previous summer). Since seasonal ice is thinner than multiyear ice (i.e., ice that has survived at least one melt season) and vulnerable to melting completely, there was a possibility that the ice edge could recede beyond the pole and leaving the pole completely ice-free. This would be fundamentally different from events in the past where a crack in the ice might temporarily expose some open water at the pole in the midst of surrounding ice. It would mean completely ice-free conditions at the geographic North Pole (just the pole, not the entire Arctic Ocean). The remarkable thing was not whether the North Pole would be ice-free or not; it was that this year, for the first time in a long time it was possible. This does not bode well for the long-term health of the sea ice
The fact that the initial analysis of potential minimum ice extent and an ice-free pole did not come to pass reflects a cooler and cloudier summer that wasn’t as conducive to ice loss as it might have been. There will always be natural variations, with cooler than normal conditions possible for a time. However, despite the lack of extreme conditions, the minimum extent in 2008 is the second lowest ever and very close to last year. Most importantly, the 2008 minimum reinforces the long-term declining trend that is not due to natural climate fluctuations.
5. The June 2008 NSIDC web site entry mentioned that it is difficult to melt first year ice at very high latitudes. Is it possible that there is a lower practical bound to ice extent, based on the very short melt season and low angle of the sun near the North Pole?
It is unlikely that there is a lower bound to sea ice extent. One of the things that helped save this year from setting a record was that the seasonal ice was so far north and did not melt as much as seasonal ice at lower latitudes would. The North Pole, being the location that last sees the sun rise and first sees the sun set, has the longest “polar night” and shortest “polar day.” Thus, it receives the least amount of solar radiation in the Arctic. So there is less energy and less time to melt ice at the pole. However there is a feedback where the more ice that is melted, the easier it is to melt still more ice. This is because the exposed ocean absorbs more heat than the ice and that heat can further melt the ice. Eventually, we will get to a state where there is enough heat absorbed during the summer, even at the shorter summer near the pole, to completely melt the sea ice. Climate models have also shown that under warmer conditions, the Arctic sea ice will completely melt during summer.
6. GISS records show most of Greenland cooler today than 70 years ago. Why should we be concerned?
We should be concerned because the warming in Greenland of 70 years ago was part of the regional warming in the North Atlantic region discussed in questions 1 and 2 above. Seventy years ago one might expect temperatures to eventually cool as the regional climate fluctuated from a warmer state to a cooler state. The current Greenland warming, while not yet quite matching the temperatures of 70 years ago, is part of a global warming signal that for the foreseeable future will continue to increase temperatures (with of course occasional short-term fluctuations), in Greenland and around the world. This will eventually, over the coming centuries, lead to significant melting of the Greenland ice sheet and sea level rise with accompanying impacts on coastal regions.
7. Antarctica seems to be gaining sea ice, and eastern Antarctica is apparently cooling. Ocean temperatures in most of the Southern Hemisphere don’t seem to be changing much. How does this fit in to models which predicted symmetric NH/SH warming (i.e. Hansen 1980)? Shouldn’t we expect to see broad warming of southern hemisphere waters?
No. Hansen’s model of 1980 is no longer relevant as climate models have improved considerably in the past 28 years. Current models show a delayed warming in the Antarctic region in agreement with observations. A delayed warming is expected from our understanding of the climate processes. Antarctic is a continent surrounded on all sides by an ocean. Strong ocean currents and winds swirl around the continent. These act as a barrier to heat coming down from lower latitudes. The winds and currents have strengthened in recent years, partly in response to the ozone hole. But while most of the Antarctic has cooled, the one part of Antarctica that does interact with the lower latitudes, the Antarctic Peninsula – the “thumb” of the continent that sticks up toward South America – is a region that has undergone some of the most dramatic warming over the past decades.
Likewise, Antarctic sea ice is also insulated from the warming because of the isolated nature of Antarctica and the strong circumpolar winds and currents. There are increasing trends in Antarctic sea ice extent, but they are fairly small and there is so much variability in the Antarctic sea ice from year to year that is difficult to ascribe any significance to the trends – they could simply be an artifact of natural variability. Even if the increasing trend is real, this is not unexpected in response to slightly cooler temperatures.
This is in stark contrast with the Arctic where there are strong decreasing trends that cannot be explained by natural variability. These decreasing Arctic trends are seen throughout every region in every season. Because much of the Arctic has been covered by multiyear ice that doesn’t melt during the summer, the downward trend in the summer and the loss of the multiyear ice has a particularly big impact on climate. In contrast, the Antarctic has very little multiyear sea ice and most of the ice cover melts away completely each summer. So the impact of any Antarctic sea ice trends on climate is less than in the Arctic. There is currently one clearly significant sea ice trend in the Antarctic; it is in the region bordering the Antarctic Peninsula, and it is a declining trend.
Because the changes in Antarctic sea ice are not yet significant in terms of climate change, they do not receive the same attention as the changes in the Arctic. It doesn’t mean that Antarctic sea ice is uninteresting, unimportant, or unworthy of scientific study. In fact, there is a lot of research being conducted on Antarctic sea ice and several scientific papers have been recently published on the topic.
8. In January, 2008 the Northern Hemisphere broke the record for the greatest snow extent ever recorded. What caused this?
The large amount of snow was due to weather and short-term climate fluctuations. Extreme weather events, even extreme cold and snow, will still happen in a warmer world. There is always natural variability. Weather extremes are always a part of climate and always will be. In fact, the latest IPCC report predicts more extreme weather due to global warming. It is important to remember that weather is not climate. The extreme January 2008 snowfall is not a significant factor in long-term climate change. One cold, snowy month does not make a climate trend and a cold January last year does not negate a decades-long pattern of warming. This is true of unusually warm events – one heat wave or one low sea ice year does not “prove” global warming. It is the 30-year significant downward trend in Arctic sea ice extent, which has accelerated in recent years, that is the important indicator of climate change.
9. Sea Surface Temperatures are running low near southern Alaska, and portions of Alaska are coming off one of their coldest summers on record. Will this affect ice during the coming winter?
It is possible that this year there could be an earlier freeze-up and more ice off of southern Alaska in the Bering Sea due to the colder temperatures. But again, this represents short-term variability and says nothing about long-term climate change. I would also note that in the Bering Sea winds often control the location of the ice edge more than temperature. Winds blowing from the north will push the ice edge southward and result in more ice cover. Winds blowing from the south will push the edge northward and result in less total ice.
10. As a result of being bombarded by disaster stories from the press and politicians, it often becomes difficult to filter out the serious science from organisations like NSIDC. In your own words, what does the public need to know about the Arctic and its future?
I agree that the media and politicians sometimes sensationalize stories on global warming. At NSIDC we stick to the science and report our near-real-time analyses as accurately as possible. Scientists at NSIDC, like the rest of the scientific community, publish our research results in peer-reviewed science journals.
There is no doubt that the Arctic is undergoing dramatic change. Sea ice is declining rapidly, Greenland is experience greater melt, snow is melting earlier, glaciers are receding, permafrost is thawing, flora and fauna are migrating northward. The traditional knowledge of native peoples, passed down through generations, is no longer valid. Coastal regions once protected by the sea ice cover are now being eroded by pounding surf from storms whipped up over the ice-free ocean. These dramatic changes are Arctic-wide and are a harbinger of what is to come in the rest of the world. Such wide-ranging change cannot be explained through natural processes. There is a clear human fingerprint, through greenhouse gas emissions, on the changing climate of the Arctic.
Changes in the Arctic will impact the rest of the world. Because the Arctic is largely ice-covered year-round, it acts as a “refrigerator” for the earth, keeping the Arctic and the rest of the earth cooler than it would be without ice. The contrast between the cold Arctic and the warmer lower latitudes plays an important role in the direction and strength of winds and currents. These in turn affect weather patterns. Removing summer sea ice in the Arctic will alter these patterns. How exactly they will change is still an unresolved question, but the impacts will be felt well beyond the Arctic.
The significant changes in the Arctic are key pieces of evidence for global warming, but the observations from Arctic are complemented by evidence from around the world. That evidence is reported in the Intergovernmental Panel on Climate Change and thousands of peer-reviewed scientific journal articles.
Let me close by putting Arctic change and climate science within the broader scientific framework. Skepticism is the hallmark of science. A good scientist is skeptical. A good scientist understands that no theory can be “proven”. Most theories develop slowly and all scientific theories are subject to rejection or modification in light of new evidence, including the theory of anthropogenic climate change. Since the first thoughts of a possible human influence on climate over a hundred years ago, more and more evidence has accumulated and the idea gradually gained credibility. So much evidence has now been gathered from multiple disciplines that there is a clear consensus among scientists that humans are significantly altering the climate. That consensus is based on hard evidence. And some of the most important pieces of evidence are coming from the Arctic.
Mr. Goddard, through his demonstrated skeptical and curious nature, clearly has the soul of a scientist. I thank him for his invitation to share my knowledge of sea ice and Arctic climate. I also thank Anthony Watts for publishing my responses. It is through such dialogue that the public will hopefully better understand the unequivocal evidence for anthropogenic global warming so that informed decisions can be made to address the impacts that are already being seen in the Arctic and that will soon be felt around the world. And thanks to Stephanie Renfrow and Ted Scambos at NSIDC, and Jim Overland at the NOAA Pacific Marine Environmental Laboratory for their helpful comments.
Thanks once again to Dr. Walt Meier from NSIDC. He has spent a lot of time answering these questions and many others, and has been extremely responsive and courteous throughout the process.
Jeff,
We must lack a common understanding of what the phrase means: “can account for the temperature trend of the past few decades.” Certainly you have seen high correlation between the PDO and temperature trends. Add in the AMO, and you have a great correlation. Temperature trends of the last few decades correlate very poorly with CO2. Now, if you use a complicated model and throw in dummy variables for aerosols, then you get a decent match. (Okay, the entries for aerosols are not completely dummy variables, but they do appear to be conveniently picked to be nearly dummy variables so that CO2 has great explanatory power.) Therefore, we have competing sets of explanation with great opportunities for further research, not a basis for drastic action loaded with unintended consequences.
Joel Shore (12:46:17)
Thank you for your reference to the AGU / AMS survey. I do not know to what extent the presence of AGU members affect the results and invalidate past impressions of the overall thought of meteorologists. Perhaps a worthy note comes from the Yale Forum (http://www.yaleclimatemediaforum.org/features/0608_tv.htm) where they observe that skepticism is more prevalent in broadcast meteorologists than in meteorologists in general. (Meanwhile, I believe there no ambiguity on the position of AMS leadership.) Also, I would like to clarify that there is a difference between human-induced climate change and CO2-induced climate change. The former (which was asked on the AGU/AMS survey) would get more “yes” responses than the latter which I referenced. For example, there appears to be general consensus in the scientific community that the Kilimanjaro glacier retreat has not been caused by CO2-induced GW but rather by human deforestation of the area.
Despite the lack of a response to my polite question about Riichard Courtney’s credentials and industry affiliation, I invested some time in reading his ‘refutation’ of AGW.
It boils down to
1. Lack of a correlation between CO2 and temperature.
This is false. Global temperature is a ‘noisy’ signal with large short-scale variability. Over the range of a few years El Nino events, aerosols from volcanos, the solar cycle and internal variablity can mask the effects of a more gradually increasing forcing such as CO2. According to this method, anything other than a linear increase in temperature would ‘disprove’ AGW, which is clearly nonsense. Remove the noise and the underlying increase in global temperatures of about 0.17C/ decade is completely consistent with anthropogenic greenhouse gas forcing.
Over a longer scale, the mid-century cooling has long been ascribed to the increase in sulpher and other aerosol pollution in the post-war industrialisation, this effect later diminished due to clean air legislation.
Twice this is stated: “This is 40 years of cooling and 28 years of warming, and global temperature is now similar to that of 1940.”
Hard to take seriously. All the instrumental records show an increase of about 0.5C since 1940
http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif
2. Change to atmospheric carbon dioxide concentration is observed to follow change to global temperature at all time scales.
Again the reasons for this are well-understood, indeed well-rehearsed and this case has been presented so often that the UK Royal Society now describe it as ‘Misleading Argument No 3’
http://royalsociety.org/page.asp?tip=1&id=6231
Can anyone explain where the Royal Society get the science wrong?
3 The pattern of atmospheric warming predicted by the AGW hypothesis is absent.
But stratospheric cooling is observed, the rise of the tropopause is observed,
http://www.sciencemag.org/cgi/content/abstract/301/5632/479
and the vertical and spatial distribution of the warming are as predicted by the theory; the data on the tropical troposphere ‘mismatch’ between model prediction and observations, which I think is what is referring to is not conclusive – see here: http://www.realclimate.org/index.php/archives/2008/05/tropical-tropopshere-ii
In short, the refutation refutes nothing.
The global cooling frenzy reported by Newsweek was no different in principle than the AGW/runaway global warming/climate catastrophe frenzy that is in current circulation
There is no realistic comparison between the two. The global cooling ‘frenzy’ consisted of a few pop science books (notably ‘The Cooling’), some op-eds and a small number of academic papers. An analysis published in the Bulletin of the American Meteorological Society reported:
During the period 1965 through 1979, our literature survey found 7 cooling papers, 19 neutral and 42 warming. In
no year were there more global cooling papers than global warming.
http://ams.confex.com/ams/pdfpapers/131047.pdf
Whereas the current GW concensus is based on several hundred peer-reviewed studies.
. If any apologist for Michael Mann’s hiding of taxpayer-funded science can provide an excuse for Mann’s refusal to disclose his taxpayer-funded data and algorithms, then now is the time to explain why the deliberate hiding of his data is acceptable.
Mann updated his conclusions in a paper published earlier this year. The full paper is available free here …
http://www.pnas.org/content/early/2008/09/02/0805721105.abstract
and every last piece of data and code is here …
http://www.meteo.psu.edu/~mann/supplements/MultiproxyMeans07/
Hope this helps.
REPLY: John, good citatations except for the Peterson paper on climate change papers of the 1970’s. I’ve met Peterson, and don’t find him credible nor capable of unbiased research. – Anthony
Two comments about your post John:
NASA says stratospheric cooling is being caused by changes in the Sun (at least that is what they conclude based on what the mission has recorded). What are your opinions about this?
But more than that, noise is created by several things that can last quite some time. These are real events. Events that are calculated into models so are well regarded by AGWists. Why do you consider all event noise to be capable of only short term noise? Some of these events are capable of long term stability. Would you then no longer consider the event to be noise but capable of producing climactic change?
Borrowed from CA comments…
“Chris:
September 24th, 2008 at 8:09 am
So kind of an anti-climax then? Today’s the day we’ve been awaiting for months – I’m sure many of us would have paid good money earlier in the summer to know what the ice extent would be exactly 365 days after the 2007 minimum! So what’s the result?
09,24,2007,4254531
09,23,2008,4873125
365 days on, the extent is 618,594 km2 or 14.5% greater.”
Anthony Watts says (in reply to John Philips’ post):
Well, if there really is a case to be made that there was a claimed consensus regarding global cooling…and alarmist talk about action needing to be taken to combat it, why haven’t we seen the case made? Why is all we get a reference to an article or two in the popular press or some popular book?
Heck, why haven’t people so far been able to come up with even one peer-reviewed paper that was predicting cooling and presented these results in an alarmist way (e.g., expressing confidence that their results are correct and that actions need to be taken)? That would seem to be a necessary, although certainly not sufficient, condition to make the case. In a previous discussion elsewhere on this, I admitted that a few such papers did exist but that this did not demonstrate that there was any claims made of a widespread consensus. However, after doing a search myself (limited to Science magazine only), I had to retract that statement because I couldn’t find ANY papers that met such a criterion. I still think it is possible they exist but it is awful strange that noone so far has been able to find even one paper meeting this criterion, let alone any evidence whatsoever that there were any credible scientific organizations like the NAS making the claim that global cooling was occurring and action needed to be taken!
Phil. (06:02:22) Oh, no, Phil., I called you a liar by omission over on Climate Audit, too, nor am I the only one. You have your value, you rarely post falsities, but for an even-handed treatment, you can’t be trusted. And I sure don’t see trustworthiness from Walt Meiers, either. Where’s the impact of cooling in his discussion?
Joel Shore, all your epicycles can’t hide the fact that the models have failed miserably. They assume more feedback from water vapor to the initial CO2 forcing than is happening.
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Reply: This goes for Phil and Kim. Please tone it down. Try to move back toward civilized discourse no matter how contentious one feels ~ charles the moderator.
Brendan H:
Hi Brendan. I agree with what you’re trying to say here:
Accountability means transparency.
The problem is that the ~$5 billion annual funding for all aspects of global warming is financially starving many other deserving science programs. Prof. Wegman, et al, show that a relatively small clique of climate scientists uncritically review each others’ submissions in a back-scratching, mutually beneficial way, in order to extract ever more global warming funding.
Most scientists are basically honest, but the people identified in Wegman’s climate science clique are either slackers who don’t bother to critically review the work of others in their clique, or their negligence is deliberate, because when their own paper is reviewed by the same small clique they want the same peer approval that generally results in increased funding requests. I personally suspect the latter is the case; very large amounts of money have corrupted climate science.
Regarding John Philips’ assertion that Michael Mann has disclosed all of his taxpayer-funded data and methodologies, that claim is false:
Re-doing the analysis with original data is currently impossible as Mann deleted the post-1960 values from the “original” data as well and the “original” data, originating from another RegEM publication by Mann and associates (Rutherford et al 2005) has never been archived (despite representations to the contrary.) [source]
Michael Mann is paid by the taxpaying public for his work. Despite any claims to the contrary, that work product is the property of the taxpayers. Yet Mann refuses to disclose essential data and algorithms that he used to create his fictitious ‘hockey stick’ chart [the algorithm he used will produce the same hockey stick pattern even when the input is random red noise, falsifying Mann’s hockey stick temperature chart].
Why does Michael Mann refuse to publicly archive his methodology and data? For one of two reasons: either he knows that his work contains significant errors that would cause it to fail the peer review process, or he is engaging in fraud.
The excuse that Mann’s taxpayer-funded work product is his own “personal intellectual property” is a bogus excuse for hiding what’s really going on. Hiding the truth in science is never acceptable.
Smokey (11:11:44) Why should these scientists hand over their work to people who just want to prove them wrong? C’mon, get real here. We’ll all get along better when we just agree that these authorities can’t be wrong.
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Still wondering why all the continental high temperature records stopped happening, what with all the global warming going on. Could global warming actually be a leveling of temperatures?
http://icecap.us/images/uploads/Continent.jpg
kim says:
And, you determine this how? Brian Soden’s work seems to show the models handling the water vapor feedback quite well: http://www.sciencemag.org/cgi/content/abstract/sci;310/5749/841 and http://www.sciencemag.org/cgi/content/abstract/sci;296/5568/727
Richard S Courtney says:
Look, my point is simply this: You responded to my analogy by stating why you thought the two cases were different. My point is simply that the statement that you make about evolutionary theory is not one that your counterparts (i.e., evolution “skeptics”) would agree with; in fact, they would make the same point about evolutionary theory that you make about AGW.
Furthermore, your statement about AGW theory is not one that I agree with, nor one that any respectable scientific body that I know of agrees with. You may call this last point an appeal to authority, but frankly I think an appeal to generally-acknowledged scientific authorities is much stronger than your appeal to your own authority.
I admit that “sloppy and desperate” may have been a bit strong. However, what I was referring to, for example, were the many errors that have been found in the Spencer and Christy analysis of the satellite record which, before they were discovered, led to the incorrect claim that the lower troposphere was not warming. Another example is the elementary error involving standard error vs standard deviation in the Douglass et al. paper of which Christy was a co-author (discussion here http://www.realclimate.org/index.php/archives/2007/12/tropical-troposphere-trends/ ). A final example involving recent work by Spencer is discussed here: http://www.realclimate.org/index.php/archives/2008/05/how-to-cook-a-graph-in-three-easy-lessons/
By the way, I do admire your general polite demeanor in these discussions. However, if you are going to complain about ad hominem attacks by others, it seems that you could also find plenty in this thread that are directed at Dr. Meier and others supporting the consensus view. I think mine was pretty mild by comparison…and, in fact, was a mixture a compliment and criticism, as I do admire Lindzen, Spencer, and Christy to the extent that they publish their ideas in the peer-reviewed literature.
Actually, although I may have been unclear, I was primarily referring here not to Lindzen, Spencer, and Christy but to those who are not publishing in reputable journals but are instead trying to shift the venue of the scientific argument to the public sphere. (I suppose my comment could also apply to Lindzen, Spencer, and Christy’s comments outside the peer-reviewed venue where I do think they have said some unfortunate things, but that wasn’t the primary issue…and, as you noted, scientists on both sides of the debate sometimes make questionable statements in the public realm.)
Could you please provide a citation for this part of the story? I made an attempt in google to try to verify your claims here but was not able to find anything that matched what you say here. I’m not saying that it is wrong, but I would like to have some evidence before accepting it as true.
John Philips says: Over a longer scale, the mid-century cooling has long been ascribed to the increase in sulpher and other aerosol pollution in the post-war industrialisation, this effect later diminished due to clean air legislation.
Can you provide studies that point to such conclusion? Thanks. At least this seems strange to me that the Chinese industrialization started to pick up at the beginning of 90’s but this didn’t prevent “the warmest decade”. Without properly collected and analyzed data your claim is nothing more than speculation. So, where is that data that supports it?
Joel Shore
You have mentioned that short term trends in global temperatures should be disregarded in favour of longer term trends. You say a few years could be weather which could skew the actual trend
Well we have had UAH satellite data from 1978 and this is what it shows.
Trend for 1978 -1994 :-
http://woodfortrees.org/plot/uah/from:1978/to:1994/trend/plot/uah/from:1978/to:1994
Trend for 1995 – 2000 :-
http://woodfortrees.org/plot/hadcrut3gl/from:1995/to:2000/trend/plot/hadcrut3gl/from:1995/to:2000
Trend for 2001 to Date :-
http://woodfortrees.org/plot/uah/from:2001/to:2009/trend/plot/uah/from:2001/to:2009
As you can see the only trend that is positive is 1995 to 2000 and a significant reason for that was the huge spike in Global temperatures around 1998 which pushed the Global averages up significantly. Even the most avid AGWers agree that this is an outlier caused by a combination of factors unconnected with CO2.
So would you agree that the actual long term Global temperature trend, as indicated by the satellite data, is down (and accelerating) with a weather event towards the end of the 20th century which is masking the true position?
Alan
I’ve met Peterson, and don’t find him credible nor capable of unbiased research
And I have never found pure ad hominem particularly pursuasive. If there is evidence that BAMS is now publishing incredible and biased research then it should be presented. The article had three authors and one of them, William Connolly, collects examples of scientific documents concerning the 1970’s cooling meme. If anyone has any examples I am sure he would welcome the opportunity to give them a wider airing.
To quote the Stoat: I am interested in “Was an imminent Ice Age predicted in the ’70’s by scientists, in scientific journals?”. That means articles in scientific journals and reputable books. I am not particularly interested in what appeared in the popular press or on TV and do not intend to discuss it here (but see context), since I do not regard these as reliable sources for scientific information.
Note that many of the oh-there-was-an-ice-age-predicted type articles tend to focus on non-science articles for their sources: newsweek, for example. This is cheating on their part. Newsweek isn’t science, of course. If newsweek was quoting peer-reviewed journals, then they should go back to those.
http://www.wmconnolley.org.uk/sci/iceage/
the actual long term Global temperature trend, as indicated by the satellite data, is down (and accelerating) …
LOL! Very ingenious, but why chop up the data into these arbitrary time periods? Presumably if we stitch the periods back together and plot all the points it will show your downward trend, yes?
http://woodfortrees.org/plot/uah/from:1978/to:2009/trend/plot/uah/from:1978/to:2009
Ooops! A positive trend, warming at the rate predicted by greenhouse gas theory!
Joel (12:24:11) Sure, I’m not positive that the water vapor feedback is the main flaw in the models and I’m sure it’s not the only one. Clouds and convection are also inadequately dealt with; they are inherently very difficult.
But, we know the models have failed, and we know the expected amount of water vapor has not appeared in the real atmosphere. That would be a large clue to a problem in the models.
Repeatedly, you show me fantastical models, and ignore the real data that is disconfirming them.
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John Philips (13:03:57) You damage your argument when you bring William Connolley into it. He is the main reason that a so-called open source knowledge base like Wikipedia is terminally corrupted so far as climate science goes. Someday his work editing Wikipedia content about climate is going to be a cautionary tale about the dangerous frontier between politics and science.
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John
I agree but Joel Shore has been banging on about 30 years data being ‘Climate’ ( yeah right!) not weather. Also that periods of upto 8 years or more contrary to the trends in the models are to be expected and indeed ‘prove’ somehow the efficacy of these models.
I was just illustrating with a 31 year period that the only reason for the overall positive trend is a period of 6 years which was contrary to the general negative trend and that this 6 year period contained some seriously outlier data.
Alan
Jordan says:
I’ll let John Philips dig up the studies but just to add a little more explanation: It is not only that the sulfate aerosol pollution from First World countries started to decrease, it also has to do with the different residence time of CO2 and of sulfate aerosols in the atmosphere. Sulfate aerosols wash out pretty quickly, so their current atmospheric concentration (and the resulting negative forcing) is mainly determined by the current emissions levels. By contrast, CO2 remains in the atmosphere for a long time so what determines the current atmospheric concentration (and the resulting positive forcing) is the cumulative emissions.
In such a scenario, the effect of the aerosols can dominate at some early times but eventually the cumulative effect of the increasing CO2 will “win” out in the end (unless sulfate aerosols emissions continue to increase at an exponentially-fast rate). [A mathematician could probably prove some quantitative theorems in this regard under certain sets of assumptions about the growth rates of the emissions for each but I think you can see how it works intuitively.]
John Philips (13:43:35) ‘Trends’ have become virtually meaningless lately, since the word has been so variably used, but try this: Eyeball the temperature curve as correlated to the Pacific Decadal Oscillation and you will see an excellent relationship with the cyclic cooling and warming phase of the PDO overlaid on a gradual warming trend emerging from the Little Ice Age. The recent warming phase also coincides roughly with the rise of CO2. Now that the PDO has flipped to its cooling phase the temperature graph is still going with the PDO and not the rising CO2. This is a powerful argument that the underlying trends and cycles have a much larger effect on climate than CO2.
Now, if the sun is going to hibernate for however long, then the underlying warming trend may reverse to a cooling trend.
I know that is not tremendously scientific, but when science is having a difficult time defining a meaningful climate trend, see Koutsoyiannis, then the larger language is going to have to suffice. My meaning is not easy to mistake.
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Alan Millnar,
I think John Philips has answered your question very well. I find your approach to be a rather amusing example of the contortions that people will put themselves through to arrive at the result that they want from some data!
By the way, there is sort of an analogy here to the stock market: It is often noted by the sort of people who write mutual fund reports that if you just missed a few short periods of time in the market over the last few decades (e.g., say, the N best weeks where N is a fairly small number), you would have missed out on nearly all of the stock market gains. However, this does not mean that we can simply throw these weeks out of our analysis as “short term fluctuations” and say that the stock market hasn’t risen nearly as much as we think it has when we look at the starting point and the ending point!
Joel (12:24:17) Ahem. Lower tropospheric temperatures are dropping now. The errors in the UAH model were corrected a decade ago. You are a sophist who is not seeking the truth and I have stronger words, but I’ll not use them, in deference to your use of civil language and in obedience to the editors.
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Maybe back then scientists worth a grain of salt had a habit of not jumping on the popular bandwagon. Besides there was no real payback in doing that. Nowadays if you’re on the bandwagon you get lots more free press and lots more dollars. Back then you didn’t get anything but a grant now and then, regardless of whether or not you were on a bandwagon. Today there is much greater incentive to say the right words and be engaged in the right research. I think that global warming appears to get “large agreement among scientists” because of this: There are more articles on global warming because there are more places to put articles on global warming.
Joel Shore wrote:
I think that should give us reassurance that when the NAS and their counterpart organizations in the G8+5 countries now make a strong statement regarding climate change they are not jumping to conclusions but are being careful and methodical.
Yes, it sounds like Hansen is being careful and methodical:
“If we don’t get this thing under control we are going to destroy the creation,” said James Hansen, who heads the NASA Goddard Institute for Space Studies and was one of the first scientists to raise the alarm about global warming in the 1980s.
Speaking to more than 500 people at the Kansas Wind and Renewable Energy Conference, Hansen called for policymakers to phase out coal-burning power plants by 2030. This will reduce carbon dioxide emissions that he said have already caused serious and possibly irreversible damage to Earth.
“We do have a planetary emergency,” Hansen said.
http://www2.ljworld.com/news/2008/sep/23/nasa_climate_expert_warns_dire_consequences_global/
With the sad state of raw data and the fudging that goes with it, I think they ought to get back to “careful and methodical” and back away from their hysterical conclusions.
Joel (14:09:23) Let’s just call your CO2=AGW paradigm a speculative bubble.
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