Speaking separately to historically black Morehouse College in Atlanta in April, Environmental Protection Agency Administrator Gina McCarthy proposed new rules in terms of social justice, as poor black communities are disproportionately affected by air pollution.

 

The meetings, and hundreds more like them over the past year, mark an unprecedented campaign by the White House and the EPA to win broad public and state backing for rules expected to come June 2 to limit for the first time carbon emissions from power plants, which are the biggest source of greenhouse gases.

 

The proposed curbs will form the cornerstone of Obama's climate action plan, a multi-layered blueprint for fighting global warming unveiled a year ago. The plan is critical to fulfilling U.S. commitments to reduce emissions agreed to at an international forum in Copenhagen in 2009.

 

It is also key to carving out a legacy for Obama's second term, after the administration was frustrated in its efforts to make progress on other goals such as immigration reform and gun control. Taking strong steps to fight climate change could be the biggest achievement of the last two years of his presidency, administration officials say.

 

The regulations, drafted under the rarely-used section 111d of the Clean Air Act, will curb the amount of carbon dioxide the country's power plants spew out and give each state a year to devise a tailored plan for how it will meet the new standards.

 

The White House has been preparing Americans for the sweeping new rules with an increasingly urgent messaging campaign about the seriousness of climate change.