The rules may also face legal hurdles if opponents challenge them in court. Although the Supreme Court has upheld the EPA's authority to regulate greenhouse gases under the Clean Air Act, the issue remains largely uncharted waters. In one sign of the ongoing legal maneuvering over how much the government can do to tackle emissions, the Supreme Court on Monday said it will consider reinstating an EPA rule overturned by a lower court that would have used the cross-state air pollution rule to impose restrictions on emissions on plants in upwind states.
Another ticking clock is a goal Obama outlined in in his first year in office, during global climate talks in Copenhagen, to cut U.S. carbon emissions by about 17 percent by 2010, compared to 2005 levels. The U.S. for years appeared headed to meet that goal, helped by rock-bottom natural gas prices that made it cheaper for plants to shift from coal to cleaner-burning natural gas. But government data shows that the trend is starting to reverse, raising questions about whether the U.S will be able to meet the goal unless Obama intervenes.
"The administration has no chance of meeting the 17 percent reduction target without such a rule," said Conrad Schneider of the Clean Air Task Force.
Living up to international obligations reflects another challenge for Obama's climate change push: Americans, by and large, are less concerned than their counterparts about what the warming of the planet will mean for them. Just 40 percent of Americans said climate change is a major threat to the U.S. in a poll the Pew Research Center conducted in 39 countries in March and April. Globally, 54 percent of people said climate change threatened their country.
AP News Survey Specialist Dennis Junius contributed to this report.
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