Global Warming Skepticism
Global warming (or more correctly, global climate change because the effect doesn't always result in local warming) is the scientific theory (see note 1) that the Earth's climate is changing as a result of changes in concentration of atmospheric gas, and this is usually extended to the idea that a significant part of the process is caused by human activity such as burning carbon-based fuels (see note 2).
It is a contentious issue because, while its fundamentally scientific in nature, the problem and the proposed solutions, have a significant political and economic effect (see note 3). There is also a less well defined social aspect where a certain group, especially the more conservative politically, seem to have a philosophical issue which is never entirely explained but is often exhibited as a distrust of science or of what they see as environmentalism. This page discusses if global wamring skepticism is reasonable.
Global warming is a complex scientific theory (see note 1) and the evidence is very difficult to interpret, especially for non-specialists. There are many other areas of science which are difficult to understand and non specialists don't generally express their opinions on these (quantum physics, advanced statistics, etc). Unfortunately, because of the political, economic and social aspects of this subject many people who have no skill in the area have commented without thoroughly checking their facts first. There is also a deliberate campaign to confuse the issue by pressure groups who might be adversely affected by proposed steps to minimise warming (see note 4).
I don't have space here to actually discuss the evidence for global warming or why the evidence against global warming is not credible. The evidence for warming is listed at the Wikipedia entry (see sources of further information, below) and the refutation of the deniers "evidence" is listed in the New Scientist article (also in the further information section).
Global warming is a scientific phenomenon being studied by scientists, so what do the scientists actually say? Contrary to the misinformation being distributed by global warming deniers there is an overwhelming consensus supporting the reality of global warming and its anthropogenic origin (see note 5).
So what is this consensus? Wikipedia lists statements by these concurring organizations: Intergovernmental Panel on Climate Change (IPCC) 2007, Joint science academies 2007, Joint science academies 2005, Joint science academies 2001, Network of African Science Academies, U.S. National Research Council 2001, American Meteorological Society, Royal Meteorological Society (UK), World Meteorological Organization (WMO), American Geophysical Union, American Institute of Physics, American Astronomical Society, American Physical Society, Federal Climate Change Science Program 2006, National Oceanic and Atmospheric Administration, National Center for Atmospheric Research, American Association for the Advancement of Science, Stratigraphy Commission of the Geological Society of London, Geological Society of America, American Chemical Society Engineers Australia (The Institution of Engineers Australia), The Canadian Meteorological and Oceanographic Society, European Geosciences Union, International Union of Geodesy and Geophysics, and the International Council for Science.
The following organisations are noncommittal: American Association of State Climatologists, and American Association of Petroleum Geologists (AAPG).
So what about dissenting organisations? Here's what Wikipedia says: "With the July 2007 release of the revised statement by the American Association of Petroleum Geologists, no remaining scientific body of national or international standing is known to reject the basic findings of human influence on recent climate." (see note 5)
If this doesn't prove the consensus then consider this. A 2004 article by Naomi Oreskes summarized the scientific literature on climate change and concluded that there is a scientific consensus on the reality of anthropogenic climate change. The author analysed 928 abstracts (chosen objectively using relevant search terms) from refereed scientific journals between 1993 and 2003 and found 75% of the abstracts indicated explicitly or implicitly acceptance of the consensus view; 25% didn't take a position on it and none of the abstracts disagreed with the consensus position. The author found this "remarkable".
So where does the debate amongst scientists, which is often mentioned on denial sites come from? Quite simply, it doesn't exist. Its a blatant lie which they (correctly) assume most people won't discover because they don't research the issue. The only significant debate comes from non-scientific groups, often with a political or economic stake in the issue.
Faced with the overwhelming opinion in favour of the reality of climate change many deniers resort to conspiracies and claim there is a pressure on scientists to produce results in favour of warming. Threats listed vary from refusal to fund research to physical threats on a researcher's life. None of these are ever reinforced with credible references.
The reality actually appears to be the opposite. There is significant pressure not to publish research which supports global warming, the IPCC is usually criticised as being too conservative, not too alarmist (see note 6), and the Bush administration has changed scientific findings to make global warming seem less of a threat.
An Associated Press release on January 30, 2007 says "Climate scientists at seven government agencies say they have been subjected to political pressure aimed at downplaying the threat of global warming." and "The groups presented a survey that shows two in five of the 279 climate scientists who responded to a questionnaire complained that some of their scientific papers had been edited in a way that changed their meaning. Nearly half of the 279 said in response to another question that at some point they had been told to delete reference to "global warming" or "climate change" from a report." (see note 7)
So in summary the scientific consensus is clearly and overwhelmingly in favour of the phenomenon existing and strongly in favour of the idea that human activity is a significant contributor to the problem. There is no significant disagreement amongst credible groups but the political pressures which are a major part of the issue have given the false impression that this is the case.
The evidence is complex and pressure groups deliberately confuse the issue, but the scientific consensus on the subject is clear. Global warming is real and significantly affected by human activity. So I give skepticism or denial of global warming a moderate score on the crap-ometer!
1. A scientific theory isn't necessarily anything which is uncertain or subject to likely change. Everything in science can potentially be modified, but well accepted theories rarely are. Therefore it is important not to confuse the scientific meaning of the word "theory" with the more common meaning (which might more correctly be called a hypothesis in the scientific sense).
2. The definition of global warming at Wikipedia is "Global warming is the increase in the average temperature of the Earth's near-surface air and oceans in recent decades and its projected continuation." See Wikipedia, Global Warming for details.
4. See the Union of Concerned Scientists site for a discussion of the phenomenon of deliberate confusion being caused by pressure groups.
5. The scientific consensus on the subject is well explained by Wikipedia at scientific opinion on climate change.
6. Wikipedia includes this quote "In a way, it is one of the strengths of the IPCC to be very conservative and cautious and not overstate any climate change risk" - Stefan Rahmstorf. See the conservative nature of IPCC reports.
7. Kerr, Richard A. (2005), "Climate Change: Hedging Your Climate-Change Bets", Science 310 (5747): 433.
Sources of Further Information
There are many web sites with information on this subject, but many have a political bias. I suggest being cautious of any which don't cite scientific papers or who reveal their bias through political statements or references to conspiracy theories.
Wikipedia, Global warming An
overview of the subject.