Fossil fuel companies have been funding smear（诽谤，污点） campaigns that raise doubts about climate change, writes John Sauven in the latest issue of Index on Censorship magazine. Environmental campaigner Sauven argues: "Some of the characters involved have previously worked to deny the reality of the hole in the ozone layer, acid rain and the link between tobacco and lung cancer. And the tactics（策略，战术） they are applying are largely the same as those they used in the tobacco wars. Doubt is still their product."

Governments around the world have also attempted to silence scientists who have raised concerns about climate change. Tactics used have included: the UK government spending millions infiltrating peaceful environmental organisations; Canadian government scientists barred from communicating with journalists without media officers; and US federal scientists pressured to remove words 'global warming' and 'climate change' from reports under the Bush administration.

Writing about government corruption in the Indian mining industry, Sauven says: "It will be in these expanding economies that the battle over the Earth's future will be won or lost. And as in the tobacco wars, the fight over clean energy is likely to be a dirty one."