The stereotypical environmental debate is between people who favor "command and control" regulation (big government) and those who favor market mechanisms (small government). Democrats and most environmentalists are thought to be on one side, Republicans and "free market" environmentalists on the other.
This is a woefully imprecise and outdated way of describing the current political landscape. It’s a large and complex topic, too much to chew over in one blog post. But Kevin Drum, writing on an unrelated subject, nails perhaps the most salient fact:
One of the underreported stories of the past few years is the evolution of the Republican Party from being the party of capitalism and free enterprise to being merely the party of whichever business interests can help Republicans get reelected. There’s a big difference between being pro-market and being pro-business — in fact, they’re often diametrically opposed ….
What the environmental movement advocates for — some small subset of which is eventually adopted by politicians, mostly but not all Democrats — is a not-particularly-coherent melange of regulation, legislation, cultural persuasion, and market-mechanisms.
For the most part, what the Republican establishment offers is coherent: A set of policies designed to benefit (or minimize impact on) a particular set of business interests. This is how one can make sense of their environmental initiatives — "Healthy Forests," "Clear Skies," mercury regulations, particulate regulations, and the recent Asia-Pacific Partnership on Clean Development and Climate. To find the motivation for the proposal, find out what business interests benefit. I wish it weren’t that simple, but it is.
The number of players in environmental debates genuinely arguing from a small-government, pro-free-market perspective is tiny, and their effect on policy is negligible.
The real argument is taking place between those who have the best interests of the environment at heart — though I freely acknowledge that their strategies and tactics are in dire need of updating — and those whose primary allegiance is to the business interests that vouchsafe their political power. These two categories do not overlap neatly with the two political parties, but it seems to me indisputable that the entrenched Republican establishment is, with a few exceptions, on the latter side.