The American Geophysical Union adopted a position statement concerning climate change in December 2007 which can be found here.
The position begins,
The Earth’s climate is now clearly out of balance and is warming.
Many components of the climate system—including the temperatures of the atmosphere, land and ocean, the extent of sea ice and mountain glaciers, the sea level, the distribution of precipitation, and the length of seasons—are now changing at rates and in patterns that are not natural and are best explained by the increased atmospheric abundances of greenhouse gases and aerosols generated by human activity during the 20th century.
It does not surprise me to see individuals in an organization dissenting with the official view, which may be a majority view (it’s hard for “organizations” to say anything, they are made of real people and it’s hard to get thousands of real people to agree on anything). Andy Revkin tried to get a good analysis of who accepted the position statement and who didn’t here . He bolded the comments of AGU members so their posts are readily identified.
Anyways, I happened to catch a forum in EOS, November 11 Vol. 89, 46. This is a copy (PDF) which may require subscription. The article was by Cyril Galvin, a coastal engineer, who expressed explicit dissent of the AGU’s position statement. He is certainly entitled to his views, but I was very surprised to see the reasons for that dissent
1. “A team of NASA and university scientists has detected an ongoing reversal in Arctic Ocean circulation triggered by atmospheric circulation changes that vary on decade- long time scales. The results suggest not all of the large changes in Arctic climate in recent years are a result of longterm trends associated with global warming.” This is the first paragraph of an article by Alan Buis of the Jet Propulsion Laboratory, appearing on page 32 of a 41- page NASA newsletter (The Earth Observer, 20(1), January- February 2008). It was derived from a 2007 article in Geophysical Research Letters by J. Morison et al. (34, L07602,
This is interesting but not at all surprising. No one serious has said that all of the Arctic variability is due to anthropogenic factors. All this is saying is that natural variability and weather happens. I happened to e-mail Dr. Morison a few months ago to ask him his thoughts on the relative influence of natural and anthropogenic factors and his response was that he thought about half of the observed variability is due to natural factors, but was worried that when natural variability (such as ice exportation from a rising AO) were superimposed on a long-term trend, the sea-ice system could have problems returning to its original state. The AO has relaxed since the 1990′s and may be going positive again, but no one has explained the observed variability with natural variability alone. In fact, there are two recent papers detecting recent anthropogenic influence, here and here.
In global warming discussions, much is made of the supposed agreement between climate models and data. But even supposing that theory agrees with data (or that data agree with theory), I believe that the “apparent correlation between theory and data is no guarantee that the theory accurately describes the phenomenon” and “[d] emonstration of agreement between a proposed theory and a given set of data is no proof that the theory is valid.” The above quotations, which are from my 1967 review of longshore currents (Reviews of Geophysics,
5(3), 301, 303, August 1967), are general statements, applicable to all fields in science. Their generality is affirmed in the American Association for the Advancement of Science book Benchmarks for Science Literacy (1993), which states that demonstration of correlation is not proof of cause -and- effect relations, and that students should know this “by the end of the 12th grade.” “A believable correlation between two variables doesn’t mean that either one causes the other…” (p. 230; see also pp. 226 and 270″
I agree with this. Correlations and process by elimination, etc are not very convincing. In 1896, Svante Arrhenius predicted the global temperature response to a doubling of carbon dioxide which was not remarkably different from today’s best estimates (it was on the high end). He did not have any CO2 or temperature data to get correlations off of. The infamous Vostok plot of CO2 and temperature going back several hundred thousand years was not available to him. He had no fancy models. This “theory” stems from physical principles in radiative transfer and the attribution is not based on a good correlation, but quantitative analysis of radiative forcings for different external agents, various fingerprints (like stratospheric cooling, etc) that cannot be explained by solely natural variability. See The Scientific Basis for Anthropogenic Climate Change
The prevailing assumption in the press, in legislative considerations, and in climate science is that global warming causes sea level rise, which causes beach erosion. The link supposed between global warming and sea level is demonstrated by a Google search of the World Wide Web: The words “sea level” and “global warming” occur together 1,830,000 times (Google data on 22 September 2008), more than any other effect listed by the AGU statement except precipitation, which exceeds sea level by only about 1%.
I don’t quite understand the connection. A Google Search of ‘Global Warming Deniers and nazis’ reveals almost 34,000 results. I’m not sure I’d make any connection based on that. The scientific literature suggests Eustatic sea level rise is 3.3 mm/yr now. Galvin downplays the effect of sea level rise (particularly by comparing the trend with annual cyclicity), and spends quite a bit of time talking about localized erosion, however estimates suggest millions of people will be effected by just a meter of sea level rise, and be significantly costly, and the sea level rise is real as a result of thermal expansion of warmer waters and ice melt.
In summary, disagreeing with the “consensus” is fine, but rational reasons should be given for doing so, especially by scientists. This was not. There is nothing especially sloppy about the writeup, but it does not strike me as being written by someone following closely in the field of climate (change).