Environmental skeptics have argued that the extent of harm coming from human activities is less certain than some scientists and scientific bodies claim, or that it is too soon to be introducing curbs in these activities on the basis of existing evidence, or that further discussion is needed regarding who should pay for such environmental initiatives. One of the focus themes in the environmental skeptics movement is the idea that environmentalism is a growing threat to social and economic progress and the civil liberties.
The popularity of the term was enhanced by Bjørn Lomborg's book The Skeptical Environmentalist. Lomborg approached environmental claims from a statistical and economic standpoint, and concluded that often the claims made by environmentalists were overstated. Lomborg argued, on the basis of cost-benefit analysis, that few environmentalist claims warranted serious concern. However, in 2010, Lomborg reversed his position and he now agrees with "tens of billions of dollars a year to be invested in tackling climate change" and declared global warming to be "undoubtedly one of the chief concerns facing the world today" and "a challenge humanity must confront". He summarized his position, saying "Global warming is real - it is man-made and it is an important problem. But it is not the end of the world."
Environmentalist organizations and lobbies argue that such widespread skeptical doubts have not developed independently, but have been "encouraged by lobbying and PR campaigns financed by the polluting industries". Supporters of environmentalists argue that "skepticism" implies a form of denialism, and that, in the US particularly, "large donations [have been made] to Senators and Congressmen and [have] sponsored neoliberalthink tanks and contrarian scientific research. ExxonMobil, the oil major, has been accused by Friends of the Earth and others of giving millions of dollars to a long list of think-tanks and lobbyists opposed to Kyoto."
A recent study from progressive authors about the environmental skepticism movement claim that the overwhelming majority of environmentally skeptical books published since the 1970s were either written or published by authors or institutions affiliated with right-wing think tanks. They "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."