By Bryan Walsh

Maybe it happened the day after Hurricane Katrina or the night Al Gore won an Oscar for An Inconvenient Truth, but the first phase of the global-warming debate has ended. Even Skeptic-in-Chief George W. Bush recently convened a global-warming summit, where Condoleezza Rice told foreign diplomats that “climate change is a real problem–and human beings are contributing to it.”

But the climate wars are far from over, and there are still dissidents emerging to challenge the green mainstream. Unlike past skeptics, they accept the basics of global warming but question its severity and challenge the orthodox faith that Kyoto Protocol-style mandatory carbon cuts are the best way to save the planet. Call them the bad boys of environmentalism: gadflies like the Danish economist Bjorn Lomborg, who just came out with the book Cool It, and rebel greens like the political consultants Ted Nordhaus and Michael Shellenberger, who detail their apostasy in Break Through. While their solutions may be flawed, the questions these contrarians raise about climate change are central as we shift into the next and more difficult phase in the debate: what should be done about it.

Lomborg is the right’s favorite environmentalist, and it’s easy to see why. Though he believes that the world is getting warmer and that humankind is causing it, Lomborg’s not too worried. Endangered polar bears? He insists that they’re actually thriving. Rising sea levels swamping coastal cities? Lomborg argues that floods won’t be biblical and that man-made defenses will be sufficient. The main effect of global warming, he writes, may be that “we just notice people wearing slightly fewer layers of winter clothes on a winter’s evening.”

The Dane’s grasp of climate science seems shaky at best. The polar bear is far from O.K.: the U.S. Geological Survey reported last month that two-thirds of the population will disappear by 2050 because of shrinking sea ice. But his main argument is still worth considering. Lomborg believes that it would be far too costly to reduce global carbon emissions enough to actually cool the climate. Since warming is coming no matter what we do and poor countries will suffer the most from it, we should instead direct scarce resources to helping those nations adapt to climate change. That means improving health-care systems and aiding economic growth so that poor countries are better prepared for calamities ahead, climate-related or not. Lomborg is correct to point out that if we’re so worried about the future famines and diseases and refugees of a warmer world, we might want to first do a little more for the hundreds of millions suffering from those catastrophes right now.

Americans Nordhaus and Shellenberger have backgrounds in both politics and environmentalism, and they mercilessly skewer the political mistakes of the green movement. For all the public attention climate change has won, U.S. greens have so far failed to achieve national political action on the issue–and the authors insist that won’t change as long as environmentalism remains wedded to what they call the “politics of limits.” Mandatory emission cuts alone won’t be enough to drive the kind of innovation needed to break the world of its fossil-fuel habit–and China and India will never sign on to caps that could limit economic growth. Instead, Nordhaus and Shellenberger argue for Apollo-program-style government investment in clean-energy research, on the order of $30 billion a year. It’s a smart, if not wholly original idea–not least because it would allow greens to frame climate change as an inspiring challenge, not just a pending catastrophe. And that’s a contrarian position that just might help win the climate wars.