If you pay attention to denialists, of any stripe, you will notice they are almost universally from a field outside the one they are criticizing. Deniers of biological evolution are almost never biologists, deniers of climate change are almost never climatologists, etc. It is enough to make you wonder if they are motivated by something other than science. The fact that these denialist groups are overwhelmingly of a particular political persuasion increases that suspicion. Thus, it is small wonder that a recent study found 92% of environmentally skeptical books were connected in some way to conservative think tanks:
"...of the 141 books which promote environmental scepticism, 130 (92.2 per cent) have a clear link to one or more CTTs -either via author affiliation (62 books) or because the book was published by a CTT (five books) or both (63 books). Furthermore, most of the remaining 11 books clearly reflect a conservative ideology, but are not connected to a CTT and are not coded as such here. Indeed, it appears that only one of the 141 books was written by a current self-professed liberal - Greg Easterbrook (1995).
Our analyses of the sceptical literature and CTTs indicate an unambiguous linkage between the two. Over 92 per cent of environmentally sceptical books are linked to conservative think tanks, and 90 per cent of conservative think tanks interested in environmental issues espouse scepticism. Environmental scepticism began in the US, is strongest in the US, and exploded after the end of the Cold War and the emergence of global environmental concern stimulated by the 1992 Earth Summit. Environmental scepticism is an elite-driven reaction to global environmentalism, organised by core actors within the conservative movement. Promoting scepticism is a key tactic of the anti-environmental counter-movement coordinated by CTTs, designed specifically to undermine the environmental movement's efforts to legitimise its claims via science. Thus, the notion that environmental sceptics are unbiased analysts exposing the myths and scare tactics employed by those they label as practitioners of 'junk science' lacks credibility. Similarly, the self-portrayal of sceptics as marginalised 'Davids' battling the powerful 'Goliath' of environmentalists and environmental scientists is a charade, as sceptics are supported by politically powerful CTTs funded by wealthy foundations and corporations."
One does not need to be a conspiracy theorist to see how this works. People in industries with an economic interest in the status quo with regard to environmental issues fund groups to attack the science behind whatever threatens their profit margins. This strategy depends on the scientific illiteracy and political loyalty of their audience, which sadly, looks like a safe bet in modern America. It is the exact same strategy used by the cigarette companies to deny the cancerous nature of their product, and indeed, as has been shown by others, often involves the very same people. Conservative think tank is quickly becoming an oxymoron. They have become shills for anti-science.