http://www.sciencemag.org/cgi/content/full/306/5702/1686 "BEYOND THE IVORY TOWER: The Scientific Consensus on Climate Change Naomi Oreskes* Policy-makers and the media, particularly in the United States, frequently assert that climate science is highly uncertain. Some have used this as an argument against adopting strong measures to reduce greenhouse gas emissions. For example, while discussing a major U.S. Environmental Protection Agency report on the risks of climate change, then-EPA administrator Christine Whitman argued, "As [the report] went through review, there was less consensus on the science and conclusions on climate change" (1). Some corporations whose revenues might be adversely affected by controls on carbon dioxide emissions have also alleged major uncertainties in the science (2). Such statements suggest that there might be substantive disagreement in the scientific community about the reality of anthropogenic climate change. This is not the case. The scientific consensus is clearly expressed in the reports of the Intergovernmental Panel on Climate Change (IPCC). Created in 1988 by the World Meteorological Organization and the United Nations Environmental Programme, IPCC's purpose is to evaluate the state of climate science as a basis for informed policy action, primarily on the basis of peer-reviewed and published scientific literature (3). In its most recent assessment, IPCC states unequivocally that the consensus of scientific opinion is that Earth's climate is being affected by human activities: "Human activities ... are modifying the concentration of atmospheric constituents ... that absorb or scatter radiant energy. ... [M]ost of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations" [p. 21 in (4)]. PCC is not alone in its conclusions. In recent years, all major scientific bodies in the United States whose members' expertise bears directly on the matter have issued similar statements. For example, the National Academy of Sciences report, Climate Change Science: An Analysis of Some Key Questions, begins: "Greenhouse gases are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise" [p. 1 in (5)]. The report explicitly asks whether the IPCC assessment is a fair summary of professional scientific thinking, and answers yes: "The IPCC's conclusion that most of the observed warming of the last 50 years is likely to have been due to the increase in greenhouse gas concentrations accurately reflects the current thinking of the scientific community on this issue" [p. 3 in (5)]..." Others agree. The American Meteorological Society (6), the American Geophysical Union (7), and the American Association for the Advancement of Science (AAAS) all have issued statements in recent years concluding that the evidence for human modification of climate is compelling (8). The drafting of such reports and statements involves many opportunities for comment, criticism, and revision, and it is not likely that they would diverge greatly from the opinions of the societies' members. Nevertheless, they might downplay legitimate dissenting opinions. That hypothesis was tested by analyzing 928 abstracts, published in refereed scientific journals between 1993 and 2003, and listed in the ISI database with the keywords "climate change" (9). The 928 papers were divided into six categories: explicit endorsement of the consensus position, evaluation of impacts, mitigation proposals, methods, paleoclimate analysis, and rejection of the consensus position. Of all the papers, 75% fell into the first three categories, either explicitly or implicitly accepting the consensus view; 25% dealt with methods or paleoclimate, taking no position on current anthropogenic climate change. Remarkably, none of the papers disagreed with the consensus position. Admittedly, authors evaluating impacts, developing methods, or studying paleoclimatic change might believe that current climate change is natural. However, none of these papers argued that point. This analysis shows that scientists publishing in the peer-reviewed literature agree with IPCC, the National Academy of Sciences, and the public statements of their professional societies. Politicians, economists, journalists, and others may have the impression of confusion, disagreement, or discord among climate scientists, but that impression is incorrect. The scientific consensus might, of course, be wrong. If the history of science teaches anything, it is humility, and no one can be faulted for failing to act on what is not known. But our grandchildren will surely blame us if they find that we understood the reality of anthropogenic climate change and failed to do anything about it. Many details about climate interactions are not well understood, and there are ample grounds for continued research to provide a better basis for understanding climate dynamics. The question of what to do about climate change is also still open. But there is a scientific consensus on the reality of anthropogenic climate change. Climate scientists have repeatedly tried to make this clear. It is time for the rest of us to listen. References and Notes 1. A. C. Revkin, K. Q. Seelye, New York Times, 19 June 2003, A1. 2. S. van den Hove, M. Le Menestrel, H.-C. de Bettignies, Climate Policy 2 (1), 3 (2003). 3. See www.ipcc.ch/about/about.htm. 4. J. J. McCarthy et al., Eds., Climate Change 2001: Impacts, Adaptation, and Vulnerability (Cambridge Univ. Press, Cambridge, 2001). 5. National Academy of Sciences Committee on the Science of Climate Change, Climate Change Science: An Analysis of Some Key Questions (National Academy Press, Washington, DC, 2001). 6. American Meteorological Society, Bull. Am. Meteorol. Soc. 84, 508 (2003). 7. American Geophysical Union, Eos 84 (51), 574 (2003). 8. See www.ourplanet.com/aaas/pages/atmos02.html. 9. The first year for which the database consistently published abstracts was 1993. Some abstracts were deleted from our analysis because, although the authors had put "climate change" in their key words, the paper was not about climate change. 10. This essay is excerpted from the 2004 George Sarton Memorial Lecture, "Consensus in science: How do we know we're not wrong," presented at the AAAS meeting on 13 February 2004. I am grateful to AAAS and the History of Science Society for their support of this lectureship; to my research assistants S. Luis and G. Law; and to D. C. Agnew, K. Belitz, J. R. Fleming, M. T. Greene, H. Leifert, and R. C. J. Somerville for helpful discussions. 10.1126/science.1103618 nitro
That was a subtle point. No, it was gross. Gore's film was just recently released. I'd imagine it would take some time to collect opinions from 100 people ... I concluded that those who responded must have seen the movie the first week or two. Fair assumption. Who goes out to the first week or two of a new movie? Uhh, people who want to see the movie.... Ever been to Star Wars on opening night? (You may have, I never have). Uhhh, no.... Considering the movie would present NO new evidence to an expert in the field, I place the odds very high they were true believers going in. Anyone with a differing view wouldn't waste their time. Actually, your argument is flawed. Assuming that some scientists have an agenda pro global warming theory they want to advance for political reasons, and some have an anti global warming theory they wish to advance for political reasons, both sides would have a strong reason to see the movie and comment on it, those who are pro global warming theory would look for the positive to comment on, those who are negative would look for something to criticize. Lots of right wingers went to see Fahrenheit 9/11 in order to find something in it to complain about...
Blah, you're in no position to determine whether my argument is flawed. PROOF: What percentage of 9/11 movie goers would you guess were Right Wingers? Opening night for 9/11 probably looked like a pro-choice rally. It's always a nice-twist when the opposition argues my point for me. Especially, when the unskilled are attempting to establish the flaw in it. Obiviously we are making assumptions here, but with a high degree of probability. For instance, "I doubt", there are many polictically motivated anti-"The humans are heating up the planet and ruining the world" academics out there. Have you stepped into a university lately? http://www.epw.senate.gov/pressitem.cfm?party=rep&id=257909
A position again unbridled growth that has negative consequences for quality of life both short term and long term...yes of course.
UNIVERSITY'S ARE BARREN OF RIGTH-WINGERS AND SATURATED WITH LEFTIST EXTREMISTS.' Sorry, I promised not to shout... Universitys are barren of right-winger and saturated with leftist extremists. blah
More right wing propaganda, in all caps no less. You have been posting a link to a professor at MIT who is anti global warming. So much for barren... Geez, how moronic are you, really, seriously...
Flaws in my arguments ... BLAH Disagreement == Pollictally Motivated Right Winger? You should brush up on your logic. It's funny the title of this thread is "Bush admits ..." DOES THAT MAKE HIM A LEFT-WINGER? ........... ... too,too,too funny Over and Out
Here's something a little more current........... Sixty scientists call on Harper to revisit the science of global warming from eco-logic/Powerhouse.com April 15, 2006 An open letter to Canadian Prime Minister Stephen Harper: Dear Prime Minister: As accredited experts in climate and related scientific disciplines, we are writing to propose that balanced, comprehensive public-consultation sessions be held so as to examine the scientific foundation of the federal government's climate-change plans. This would be entirely consistent with your recent commitment to conduct a review of the Kyoto Protocol. Although many of us made the same suggestion to then-prime ministers Martin and Chrétien, neither responded, and, to date, no formal, independent climate-science review has been conducted in Canada. Much of the billions of dollars earmarked for implementation of the protocol in Canada will be squandered, without a proper assessment of recent developments in climate science. Observational evidence does not support today's computer climate models, so there is little reason to trust model predictions of the future. Yet, this is precisely what the United Nations did in creating and promoting Kyoto, and still does in the alarmist forecasts on which Canada's climate policies are based. Even if the climate models were realistic, the environmental impact of Canada delaying implementation of Kyoto or other greenhouse-gas reduction schemes, pending completion of consultations, would be insignificant. Directing your government to convene balanced, open hearings as soon as possible would be a most prudent and responsible course of action. While the confident pronouncements of scientifically unqualified environmental groups may provide for sensational headlines, they are no basis for mature policy formulation. The study of global climate change is, as you have said, an "emerging science," one that is perhaps the most complex ever tackled. It may be many years yet before we properly understand the Earth's climate system. Nevertheless, significant advances have been made since the Protocol was created, many of which are taking us away from a concern about increasing greenhouse gases. If, back in the mid-1990s, we knew what we know today about climate, Kyoto would almost certainly not exist, because we would have concluded it was not necessary. We appreciate the difficulty any government has ,formulating sensible science-based policy, when the loudest voices always seem to be pushing in the opposite direction. However, by convening open, unbiased consultations, Canadians will be permitted to hear from experts on both sides of the debate in the climate-science community. When the public comes to understand that there is no "consensus" among climate scientists about the relative importance of the various causes of global climate change, the government will be in a far better position to develop plans that reflect reality, and so benefit both the environment and the economy. "Climate change is real" is a meaningless phrase, used repeatedly by activists to convince the public that a climate catastrophe is looming, and humanity is the cause. Neither of these fears is justified. Global climate changes all the time, due to natural causes, and the human impact still remains impossible to distinguish from this natural "noise." The new Canadian government's commitment to reducing air, land, and water pollution is commendable, but allocating funds to "stopping climate change" would be irrational. We need to continue intensive research into the real causes of climate change, and help our most vulnerable citizens adapt to whatever nature throws at us next. We believe the Canadian public and government decision-makers need and deserve to hear the whole story concerning this very complex issue. It was only 30 years ago that many of today's global-warming alarmists were telling us that the world was in the midst of a global-cooling catastrophe. But, the science continued to evolve, and still does, even though so many choose to ignore it, when it does not fit with predetermined political agendas. We hope that you will examine our proposal carefully, and we stand willing and able to furnish you with more information on this crucially important topic. CC: The Honourable Rona Ambrose, Minister of the Environment, and the Honourable Gary Lunn, Minister of Natural Resources Sincerely, Continued on next page.....