Obama unveils plans to curb coal power

The Obama administration will on Monday roll out a plan to cut earth-warming pollution from power plants by 30 percent by 2030, setting in motion one of the most significant actions to address global warming in US history.

A new rule, which is expected to be final next year, will set the first national limits on carbon dioxide, the chief gas linked to global warming from US power plants.

"The purpose of this rule is to really close the loophole on carbon pollution, reduce emissions as we've done with lead, arsenic and mercury and improve the health of the American people and unleash a new economic opportunity," said Frances Beinecke, president of the Natural Resources Defense Council, which has drafted a plan that informed the Environmental Protection Agency (EPA) proposal.

The regulation is a centrepiece of President Barack Obama's plans to reduce the pollution linked to global warming, a step that the administration hopes will get other countries to act when negotiations on a new international treaty resume next year.

Despite concluding in 2009 that greenhouse gases endanger human health and welfare, a finding that triggered their regulation under the 1970 Clean Air Act, it has taken years for the administration to take on America's fleet of power plants.

Power plants are the largest source of greenhouse gases in the US, accounting for about a third of the annual emissions making the US the second largest contributor to global warming on the planet.

In December 2010, the Obama administration announced a "modest pace" for setting greenhouse gas standards for power plants, setting a May 2012 deadline.

Obama put them on the fast track last summer when he announced his climate action plan and a renewed commitment to climate change after the issue went dormant during his re-election campaign.

The rule carries significant political and legal risks, by further diminishing coal's role in producing US electricity and offering options for pollution reductions far afield from the power plant, such as increased efficiency.

Once the dominant source of energy in the US, coal now supplies under 40 percent of the country's electricity, as it has been replaced by booming supplies of natural gas and renewable sources such as wind and solar.