According to science historians Naomi Oreskes and Eric Conway in their important book, "Merchants of Doubt," tobacco giant Philip Morris invented the modern tactic of merchandising scientific doubt to stave off regulation. They demonstrate convincingly that the same technique -- often involving the same few miscreant scientists -- is behind today's alarming public misunderstanding of the scientific consensus on global warming.

By sowing doubt about the link between smoking and cancer, chlorofluorocarbons and the ozone hole, second-hand smoke and cancer, and, now, a human impact on climate, scientists S. Fred Singer, Frederick Seitz and a few others used their legitimate credentials to undermine public scientific understanding, putting off regulation of environmental pollutants, sometimes for decades.

The latest ideological attack on science appears the most baffling -- the recent denunciation of Rachel Carson and her pioneering work, "Silent Spring," which led to the 1972 federal ban on DDT. Detective-like, the authors uncover the motivation behind this attempt to discredit a long-settled public health question. By suggesting that Carson and the ban were wrong -- the authors demonstrate incontrovertibly that she was right -- the implication by extension is that all government regulation is wrong.

That's the fundamental insight these historians' dogged research reveals: That this war, battled hotly in the media over often recondite fields of complex science, is not about science at all, but about antipathy to government regulation of commerce in any form, employing eager allies at the editorial pages of the Wall Street Journal and a handful of ideological institutions masquerading as "think tanks," such as the Heartland Institute, the George C. Marshall Institute and the Cato Institute.

Together they succeed in temporarily corrupting public understanding, thereby delaying the inevitable reckoning, and often making a lot of money for themselves and their stealth backers -- Exxon, for example -- along the way.

Scientists clearly proved cigarettes and second-hand smoke cause cancer; Rachel Carson was right about DDT; the ozone layer is damaged by manmade chemicals. And today the vast consensus of climate scientists is that burning fossil fuels and other human activities are altering the global climate. Within the natural -- and stated -- uncertainties of the scientific process, the evidence is irrefutable.

Also irrefutable, thanks to the rigorous scholarship of Oreskes and Conway, are the shameful practices of a few esteemed scientists serving ideological ends. "Merchants of Doubt" is a dense, heavily footnoted read. Not everyone can take the time, but many should.

The next time a friend or Fox News commentator or political candidate assaults you with the claim that "climate change isn't happening" or "isn't caused by human activities," you will recognize the source of their colossal misunderstanding. The good news is, honest science wins in the end. The bad news: The earth is heating up while this artificially heated debate rages, though "Merchants of Doubt," if widely read, should help douse the media flames.

James P. Lenfestey is a former editorial writer for the Minneapolis Star Tribune covering climate issues.