By far, the fastest-growing—and, I'd say, most significant—environmental movement in the United States is the push to stop new "dirty" coal-fired plants from being sited. Over at Grist, James Hansen, NASA's top climate expert, offers his standard brief on why that push is so critical:
Our conclusion is that, if humanity wishes to preserve a planet similar to the one on which civilization developed and to which life on Earth is adapted, CO2 must be reduced from its present [atmospheric concentrations of] 385 ppm to, at most, 350 ppm. We find that peak CO2 can be kept to ~425 ppm, even with generous (large) estimates for oil and gas reserves, if coal use is phased out by 2030 (except where CO2 is captured and sequestered) and unconventional fossil fuels are not tapped substantially.
A near-term moratorium on coal-fired power plants and constraints on oil extraction in extreme environments are important, because once CO2 is emitted to the air much of it will remain there for centuries.
Anyway, the Los Angeles Times just did a good profile of the burgeoning anti-coal movement, which started as a loose collection of local activists, but is now being spearheaded by the national green groups: "Every time a new coal-fired power plant is proposed anywhere in the United States, a lawyer from the Sierra Club or an allied environmental group is assigned to stop it, by any bureaucratic or legal means necessary." They've been stunningly successful, claiming 65 victories in the last three years, and the coal activists have started fanning out overseas, to places like India. (More on that in a bit.)
The coal industry's on high alert, of course, and is already firing back with "ads, lobbying and court briefs of their own." Some industry lawyers even occasionally ponder conspiracy charges against national organizations that prod local groups into action. The whole fracas looks similar to the pitched battles over nuclear power that took place in the 1970s, in which greens ended up prevailing. (Granted, more than a few enviros worried about climate change might take nuclear over coal right about now...) As a means of tackling fossil-fuel dependency, this sort of grassroots action isn't nearly as elegant as cap-and-trade, but it could spur a lot of the same changes—by effectively raising the price of carbon—and right now it's one of the few efforts along this front that's actually making headway.