Paul Krugman excoriates Exxon Mobil on moral, rather than economic, grounds. I've quoted more extensively than I normally would from a pay-to-access article.

To understand why Exxon Mobil is a worse environmental villain than other big oil companies, you need to know a bit about how the science and politics of climate change have shifted over the years.

Global warming emerged as a major public issue in the late 1980's. But at first there was considerable scientific uncertainty.

Over time, the accumulation of evidence removed much of that uncertainty. Climate experts still aren't sure how much hotter the world will get, and how fast. But there's now an overwhelming scientific consensus that the world is getting warmer, and that human activity is the cause. In 2004, an article in the journal Science that surveyed 928 papers on climate change published in peer-reviewed scientific journals found that "none of the papers disagreed with the consensus position."

To dismiss this consensus, you have to believe in a vast conspiracy to misinform the public that somehow embraces thousands of scientists around the world. That sort of thing is the stuff of bad novels. Sure enough, the novelist Michael Crichton, whose past work includes warnings about the imminent Japanese takeover of the world economy and murderous talking apes inhabiting the lost city of Zinj, has become perhaps the most prominent global-warming skeptic. (Mr. Crichton was invited to the White House to brief President Bush.)

So how have corporate interests responded? In the early years, when the science was still somewhat in doubt, many companies from the oil industry, the auto industry and other sectors were members of a group called the Global Climate Coalition, whose de facto purpose was to oppose curbs on greenhouse gases. But as the scientific evidence became clearer, many members — including oil companies like BP and Shell — left the organization and conceded the need to do something about global warming.

Exxon, headed by Mr. Raymond, chose a different course of action: it decided to fight the science.

A leaked memo from a 1998 meeting at the American Petroleum Institute, in which Exxon (which hadn't yet merged with Mobil) was a participant, describes a strategy of providing "logistical and moral support" to climate change dissenters, "thereby raising questions about and undercutting the 'prevailing scientific wisdom.' " And that's just what Exxon Mobil has done: lavish grants have supported a sort of alternative intellectual universe of global warming skeptics.