"Climategate" has put scientists on trial in the court of public opinion. If you believe climate sceptics, a huge body of evidence involving the work of tens of thousands of scientists over more than a century should be thrown out on the basis of the alleged misconduct of a handful of researchers, even though nothing in the hacked emails has been shown to undermine any of the scientific conclusions.
If we are going to judge the truth of claims on the behaviour of those making them, it seems only fair to look at the behaviour of a few of those questioning the scientific consensus. There are many similar examples we did not include. We leave readers to draw their own conclusions about who to trust.
1. Fun with the sun
In 1991, the journal Science published a paper by researchers Eigil Friis-Christensen and Knud Lassen, then at the Danish Meteorological Institute in Copenhagen. It included graphs that appeared to show a remarkably close correlation between solar activity and terrestrial temperatures – suggesting that other factors, such as carbon dioxide levels, have little influence on global temperatures.
The graphs were seized on by climate change sceptics and have been widely reproduced ever since. But according to Peter Laut of the Technical University of Denmark in Lyngby, the close correlations in the original graphs, and in updated versions published in 1995 and 2000, exist only because of what he describes as a "pattern of strange errors".
Laut described his findings in a peer-reviewed paper (Journal of Atmospheric and Solar-Terrestrial Physics, vol 65, p 801) and also wrote them up in a less technical form for the geophysicists' newspaper Eos (vol 85, p 370 (PDF)). His concerns about the 1991 paper are shared by a number of leading climate scientists.
Outcome: Little action has been taken following publication of Laut's papers. The 1991 paper is still frequently cited by climate deniers.
2. The great swindle
A television programme called The Great Global Warming Swindle was commissioned by the British broadcaster Channel 4 and aired in 2007.
The documentary, written and directed by Martin Durkin, prompted a voluminous complaint to the UK's broadcast regulator Ofcom, alleging 137 breaches of broadcasting regulations.
For instance, the programme showed a graph comparing temperature and solar activity since 1550, based on a 1995 paper by Friis-Christensen and Lassen. This was one of the graphs questioned by Peter Laut (see above).
In the original graph, there was a gap in the solar activity line between 1600 and 1700 because there were no sunspots at this time, as confirmed by sunspot records. In the TV programme, this gap had somehow been filled in. Friis-Christensen accused the programme makers of fabricating the data.
The programme was also alleged to have misrepresented the views of several scientists who were interviewed on camera.
Outcome: Ofcom upheld some complaints about scientists being misrepresented, but decided that the breaches of factual accuracy did not fall within its remit.
3. The Oregon petition
The Oregon Institute of Science and Medicine is a research centre in the small town of Cave Junction; it says it conducts research into "protein biochemistry, diagnostic medicine, nutrition, preventive medicine and ageing". In 1998, it issued a petition urging the US government to reject all limits on greenhouse gas emissions. The petition was mailed to thousands of US scientists, who were asked to sign it.
It was accompanied by an article entitled "Environmental effects of increased atmospheric carbon dioxide". One of the authors, Willie Soon, is a well-known climate sceptic. The article closely resembled the style of articles from the peer-reviewed journal Proceedings of the National Academy of Sciences, down to the typeface. It had not been published in that or any other journal, as the US National Academy of Sciences made clear in a statement.
Despite intense scientific criticism (see here (PDF) and here, for example) the petition attracted over 30,000 signatures – although the organisers admitted that they did little to verify the respondents' credentials, allowing obviously fake names like "Dr Geri Halliwell" to be included.
Outcome: As of 2008, the petition was being recirculated. The accompanying article has acquired an aura of respectability, having finally been published in a journal, albeit not one specialising in climatology: – the Journal of American Physicians and Surgeons.
4. Peer review?
In 2008, the Forum on Physics and Society (FPS), a newsletter produced by the American Physics Society, published an article entitled "Climate sensitivity reconsidered". The article claimed that "the IPCC's estimates may be excessive and unsafe" and that attempts to cut CO2 emissions "are pointless, may be ill-conceived and could even be harmful".
The article was written by Christopher Monckton, a British journalist and consultant. Although apparently highly technical, the piece has been strongly criticised by professional climate scientists, including Gavin Schmidt, of NASA's Goddard Institute for Space Studies, New York.
The piece was reported by the US Science and Public Policy Institute as having been "peer-reviewed".
If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.