Environmental scepticism denies the seriousness of environmental problems, and self-professed 'sceptics' claim to be unbiased analysts combating 'junk science'. This study quantitatively analyses 141 English-language environmentally sceptical books published between 1972 and 2005. We find that over 92 per cent of these books, most published in the US since 1992, are linked to conservative think tanks (CTTs). Further, we analyse CTTs involved with environmental issues and find that 90 per cent of them espouse environmental scepticism. We conclude that scepticism is a tactic of an elite-driven counter-movement designed to combat environmentalism, and that the successful use of this tactic has contributed to the weakening of US commitment to environmental protection.