The Obama administration announced long-awaited rules that would sharply limit the output of carbon dioxide emissions from new power plants, the gases that the vast majority of scientists say are the primary contributor to global climate change.

The announcement Tuesday by the Environmental Protection Agency signaled that the administration’s commitment to tackling climate change has not entirely fallen away, despite the controversy it could unleash in an election year. Delays of key EPA rules over the last six months and President Obama’s recent statements touting oil development in response to high gasoline prices stirred nervousness among environmentalists that this standard would also be shelved.

Yet by proposing the power plant rules and pressing forward with new car and truck fuel economy standards, the Obama administration has moved to cut pollution from the two largest domestic sources of greenhouse gases. Power plants themselves are the single greatest stationary source, accounting for 40% of the country’s output of carbon dioxide.

“I think the administration releasing a proposed regulation for greenhouse gases for new plants is as strong a signal that anyone can ask for about how seriously they are addressing the threat of climate change,” said Megan Ceronsky, an attorney for the Environmental Defense Fund.

The mining industry criticized the rule. “Requiring coal-based power plants to meet an emissions standard based on natural gas technology is a policy overtly calculated to destroy a significant portion of America’s electricity supply,” said Hal Quinn, chief executive of the National Mining Assn. “This proposal is the latest convoy in EPA’s regulatory train wreck that is rolling across America, crushing jobs and arresting our economic recovery at every stop. It is not an ‘all of the above’ energy strategy.”

The regulations would apply only to new power plants, not modifications to existing plants, the standards for which are expected later. The proposed rules would require new plants to emit a maximum of 1,000 pounds of carbon dioxide per megawatt hour. The newest natural-gas-fired power plants emit about 800 pounds of carbon per megawatt hour, new coal plants, between 1,600 to about 1,900 pounds per megawatt hour.

The proposed regulations further bolster a trend that the power industry began years ago, as more utilities replaced aging coal-fired plants with new natural gas plants. Very few new coal plants are now on the drawing boards.

“Still, I think it is a landmark rule, because what this essentially says is we will never be building dirty old coal plants ever again,” said Michael Brune of the Sierra Club, one of the litigants in the lawsuit that led to the development of the new rules. “The dominant power source of the 19thand 20thcenturies won’t be built the same again.”

Original source: Obama administration sets limits on emissions from new power plants