Oh I thought everyone knew about the Oregon Petition, sorry.  A fine upstanding example of astroturf in action.  You will find many an ordinary USian saying, "But wasn't there this petition that 19,000 scientists signed saying they didn't believe global warming was caused by humans?"  Thanks for the wikipedia link.

Here is a British site that references it as well.

Here's how good old Faux News used it on-air... along with a quick rundown on the petition's funders and creators:

Also circulated with the petition was a letter from Frederick Seitz, a former NAS president, that warned that "[t]he United States is very close to adopting" the Kyoto Protocol, which, according to Seitz, "would ration the use of energy and of technologies that depend upon coal, oil, and natural gas and some other organic compounds." Seitz added that "there is good evidence that increased atmospheric carbon dioxide is environmentally helpful." A June 5, 2000, item in Business Week reported that "[f]or 28 years, Seitz was also a paid director and shareholder of Ogden Corp., an operator of coal-burning power plants that stands to lose financially should the Kyoto Protocol become law." Business Week reported that Seitz "sold most of his 11,500 shares" of Ogden in 1999 -- after promoting the petition in 1998.

An article in the May 2006 edition of Vanity Fair by Mark Hertsgaard reported, in Hertsgaard's words, "in full for the first time," the real "overlap" -- exemplified by Seitz -- between "the people who deny the dangers of climate change" and the "tobacco executives who denied the dangers of smoking." Hertsgaard reported that after leaving the NAS, Seitz "helped R. J. Reynolds Industries, Inc., give away [$45 million] to fund medical research in the 1970s and 1980s," which "avoided the central health issue" of smoking and "served the tobacco industry's purposes," but that "as proof of its commitment to science," "the industry frequently ran ads in newspapers and magazines citing its multi-million-dollar research program." The article further reported that, in a paper he authored in the 1990s, Seitz "asserted that secondhand smoke posed no real health risks." The article added that Seitz is "chairman emeritus" of the George C. Marshall Institute, which is one of "an array of organizations" funded by ExxonMobil "to downplay the problem" of global warming.

Monbiot recently was interviewed  on, among other things, this convergence between the Big Tobacco lobby and the Big Fossil lobby -- perhaps between them they should found the Anti-Lung Association?

The difference between theory and practise in practise ...