Scientists and economists have been offered $10,000 each by a lobby group funded by one of the world's largest oil companies to undermine a major climate change report due to be published today.
Letters sent by the American Enterprise Institute (AEI), an ExxonMobil-funded thinktank with close links to the Bush administration, offered the payments for articles that emphasise the shortcomings of a report from the UN's Intergovernmental Panel on Climate Change (IPCC).
Travel expenses and additional payments were also offered.
The UN report was written by international experts and is widely regarded as the most comprehensive review yet of climate change science. It will underpin international negotiations on new emissions targets to succeed the Kyoto agreement, the first phase of which expires in 2012. World governments were given a draft last year and invited to comment.
The AEI has received more than $1.6m from ExxonMobil and more than 20 of its staff have worked as consultants to the Bush administration. Lee Raymond, a former head of ExxonMobil, is the vice-chairman of AEI's board of trustees.
The letters, sent to scientists in Britain, the US and elsewhere, attack the UN's panel as "resistant to reasonable criticism and dissent and prone to summary conclusions that are poorly supported by the analytical work" and ask for essays that "thoughtfully explore the limitations of climate model outputs".