The world is not coming to an end. I know: shocker! And yet there are still people who feel otherwise. These climate alarmists—whose tribe has somewhat dwindled of late—believe the seas will all too soon rise 20 feet and submerge our cities; that the noble polar bear is on the very cusp of extinction; that our planet, in sum, is hurtling toward a fiery doom.

The Danish environmentalist Bjørn Lomborg is not one of these people. True, he does believe that global warming exists, that human beings are at least partly responsible for it, and that something must be done. But in his two contrarian books, The Skeptical Enviromentalist (published in English in 2001) and Cool It (2007), Lomborg argues that the strategies employed over the last two decades—the speculative ecological horror stories, the vast siphonings of money into the cause—are outdated and ineffectual. Like the late free-market environmentalist Julian Simon, whose theories launched his own journey away from alarmism, Lomborg believes that human ingenuity is the key to planetary improvement. And now, in Ondi Timoner's provocative new documentary, also called Cool It, Lomborg travels the world to make that case in a most persuasive way.

The alarmist community's objections to Lomborg—apart from his sunny, upbeat plausibility, which must surely rankle—often concern his academic bona fides. Although his focus is on economics, statistics and cost-benefit analyses, his Ph.D., they point out, is actually in political science. So, like, what could he know? In fact, Danish scientists were so angered by The Skeptical Environmentalist that they complained to the Danish Committees on Scientific Dishonesty (paging Mr. Galileo!), which ruled that the book's conclusions were in fact "dishonest," but that, in effect, Lomborg was too ignorant to realize it. (This decision was subsequently dismissed, rather curtly, by higher Danish scientific authorities.)

In the film, Lomborg deals with this episode forthrightly. He also allows a generous amount of screen time to Stanford University environmental biologist Stephen Schneider, one of his most hostile antagonists. ("This guy needs to be taken down," Schneider says.) And he does this without bringing up Schneider's role in helping to trigger the long-building backlash against ecological alarmism with his famous remark in a 1989 magazine interview that "we have to offer up scary scenarios, make simplified, dramatic statements, and make little mention of any doubts we might have"—a foreshadowing of last year's "Climategate" email leaks.

In addition, Lomborg credits An Inconvenient Truth, the Al Gore movie, with helping to raise awareness of global warming, although through often-dubious assertions. For example, the polar bear population, Lomborg says, has actually increased since the 1960s, and is now most endangered by Arctic hunters, who shoot between 300 and 500 of the animals every year. Gore's prediction of a 20-foot rise in sea levels was wildly overwrought; but in any case, Lomborg observes, "Sea levels in the last century rose one foot—did anyone notice?" He also says that, while global warming is a serious concern, we should bear in mind that human beings manage to thrive both on the equator and at the frozen poles: "People can adapt to climate, which is always changing."

Lomborg believes that the world climate summits held in Rio, Kyoto, and Copenhagen over the last 18 years have been futile, because no country—especially such rising powerhouses as China and India, just now emerging into prosperity—will agree to cold-cock its economy in order to join the wispy Western global-warming crusade. And he claims that since the $250 billion the European Union spends every year to combat warming will ultimately reduce temperatures by only one-tenth of one percent, that money would be better channeled into worldwide battles against malaria and AIDS—diseases that are killing people right now—and into funding new climate technology.

Traveling through Europe, the U.S., and Africa, Lomborg consults with several eminent scientists (like theoretical physicist Freeman Dyson, who says that the computer climate-simulation models upon which so much ecological alarmism relies "do not begin to describe the real world we live in"); and he points out the promise of wave power, sea-borne windmills, algae-based fuel, and a prospective nuclear technology that could lead to the creation of nuclear reactors that run on nuclear waste. He also brings in Benjamin Franklin, whose observation that an Icelandic volcano eruption in 1783 had caused an abnormally severe winter in Europe suggests, Lomborg says, that artificial volcanoes could be employed to cool the Earth today.

A significant part of Lomborg's appeal lies in his lack of dogmatic certitude. In his search for concrete solutions, he never presents himself as an infallible authority, and he appears to welcome detractors. When the pugnacious Professor Schneider died last summer, before the picture's completion, Lomborg must have felt the loss of a useful critic—Cool It is dedicated to Schneider's memory.

Kurt Loder is a writer, among other things, embedded in New York.