Confronting climate change - which most scientists now say is real - is a worldwide effort. That's why it's called "global warming."
But as nations continue to argue over the Kyoto agreement and other multinational approaches, and as Congress considers an energy billthat would expand fossil-fuel production, state governments are taking the lead in reducing the greenhouse gases that seem to be sending temperatures upward.
Ten states are about to sue the administration to force the EPA to regulate greenhouse gases. Fourteen states, including President Bush's home state of Texas, now require utilities to generate part of their power from renewable sources.
One region - the Northeast - is following its own Kyoto-like path. New England states and five eastern Canadian provinces have set goals to reduce greenhouse gases to 1990 levels by 2010, then reduce them another 10 percent by 2017.
Similarly, governors on the West Coast recently announced a joint strategy to reduce global warming. Included in this effort: using their combined purchasing power to buy fuel-efficient vehicles for official use; developing uniform appliance-efficiency standards; collaborating to measure and report greenhouse-gas emissions; reducing the use of diesel generators on ships in California, Oregon, and Washington State ports.
It's not just a matter of wanting to enjoy a clearer view of the region's spectacular mountains and coastlines.
"This is a matter of economic necessity," says Oregon Gov. Ted Kulongoski (D). "Global warming is a real phenomenon, which affects us in many ways, from increasingly costly forest fires to encroaching seas."
Barry Rabe, who teaches environmental policy and political science at the University of Michigan, Ann Arbor, finds that "the current level of state activity surrounding the issue of climate change is striking."
In a study of state programs for the Pew Center on Global Climate Change, Dr. Rabe found a variety of initiatives around the country - many of them far in advance of what the federal government is doing.
"Measures that have proven controversial at the federal level, such as renewable portfolio standards and mandatory reporting of greenhouse-gas emissions, have been implemented at the state level, often with little dissent," he says.
For example, says Eileen Claussen, president of the Pew center and former assistant secretary of state in charge of environmental and scientific affairs, Texas and 13 other states now require utilities to generate a specified share of their power from renewable sources.
"Three [states] have established reporting programs for greenhouse-gas emissions, and two of these are mandatory programs," Ms. Claussen recently told state environmental officials from around the country at a meeting in Salt Lake City. "In addition, two states have overall caps on their emissions, and one state, California, is working on direct controls on emissions from motor vehicles."
Then there is New York State, she said: Under Republican Gov. George Pataki, New York has created a regional market in which power plants can buy and sell carbon-dioxide credits. Nine of 10 states have told the governor they're interested in collaborating on emission reductions across the region.
One striking thing about such efforts to stem global warming is that both Republicans and Democrats generally support them.
Even Arnold Schwarzenegger, governor-elect of California and an enthusiastic owner of a General Motors gas-guzzling Hummer, vowed in his campaign that "Under my administration, the state will lead by example - identifying and permanently retiring those heavily used vehicles that do the greatest harm to our air quality." Mr. Schwarzenegger also embraced a new state law that requires cars and trucks to emit less carbon dioxide, suggesting that he would retrofit his Hummer (with a gas mileage of 10 to 13 m.p.g.) to run on clean-burning hydrogen.
At issue between states and the Bush administration (and the subject of the lawsuit) is whether to consider carbon dioxide - one of the main greenhouse gases - as a "pollutant" regulated under the federal Clean Air Act. The Environmental Protection Agency under Bush says "no"; the states say "yes."
California officials are particularly concerned that the EPA's position will make it easier for auto manufacturers to challenge the state's first-ever law restricting vehicles' greenhouse-gas emissions. Connecticut, Illinois, Maine, Massachusetts, New Jersey, New York, Oregon, Washington, and Vermont are expected to join the suit.
Rabe at the University of Michigan and other observers see such state efforts as models for federal action. Still, they acknowledge that state programs addressing climate change are no substitute for a nationwide effort directed by Washington.
Whether acting alone or in groups, states also face stiff obstacles.
They are constitutionally limited in what they can do in areas involving international relations. And many are cash-strapped, required to balance state budgets that are as shaky as they've been in decades.