Obama to regulate greenhouse gases from power plants
The Obama administration has said it will regulate greenhouse gas emissions from power plants amid opposition from industry and Republicans in Congress.
The Environmental Protection Agency (EPA) said it would regulate emissions from fossil fuel power plants by 2011 and petroleum refineries by 2012.
President Barack Obama is pushing the EPA to cut emissions after a climate bill failed in Congress this year.
But Republican lawmakers have said the EPA's new rules will harm the economy.
The EPA said it would propose figures for emissions cuts in 2011 and finalise them in 2012.
The new rules are expected to limit the amount of carbon dioxide a plant can emit per each megawatt hour of electricity produced.
"We are following through on our commitment to proceed in a measured and careful way to reduce greenhouse gas pollution that threatens the health and welfare of Americans and contributes to climate change," EPA chief Lisa Jackson said in a statement.
Collectively, fossil fuel power plants and petroleum refineries release nearly 40% of the total greenhouse gases emitted in the US.
Republicans, who will take control of the House of Representatives when the new Congress convenes on 5 January, have already expressed opposition to the new regulations.
"I think we ought to start with a two-year pause" in upcoming EPA regulations, said Republican Representative Mike Simpson, who is expected to lead a House panel that controls the EPA's budget.
Mr Obama said last year that the US would curb emissions by 17% by 2020 compared with 2005 levels.
Legislation forcing reductions in carbon dioxide and other greenhouse gas emissions, which are believed by most climate scientists to contribute to global warming, was struck down in Congress this summer.