The US government will propose a rule Monday requiring power plants to cut by 30 percent carbon dioxide emissions by 2030 based on 2005 levels, US media reported Sunday.
The Wall Street Journal cited people briefed on the rule as saying the Environmental Protection Agency's draft measure was due to be completed within a year.
It will give leeway to US states to decide how to fulfil the reductions targets, such as through new cap-and-trade programs, deploying more renewable energy or developing energy-efficient technologies.
Although each state will have difference standards of reduction, the national average will stand at 25 percent by 2020 and 30 percent by 2030, according to the Journal.
The Washington Post said the plan would cut five million metric tons of carbon dioxide by 2030, which may make it President Barack Obama's most sweeping climate change policy.
US officials declined to comment.
The hundreds of power plants whose emissions will be controlled include about 600 coal plants, which will be the most affected by the new rule.
Power plants account for about 40 percent of greenhouse gas emissions in the United States.
Even as natural gas gains in popularity, coal remains a key component in the American energy landscape. Wyoming leads the pack of 25 states that mine the fossil fuel, followed by West Virginia, Kentucky, Pennsylvania and Illinois.
Hundreds of coal-fired power plants dotted across the country provide about 37 percent of the US electricity supply, ahead of natural gas (30 percent) and nuclear reactors (19 percent).
The Obama administration's approach has faced criticism from the coal industry and business officials who say it will cause coal miners to lose their jobs and may trigger electricity shortages.
The Electric Reliability Coordinating Council lobby group, a coal-based energy lobby, cited a study as saying that the emissions limits would cost 2.85 million lost jobs and $13 to $17 billion a year to consumers from 2018 to 2033.
The group also expressed concern that the new rule could place the United States at a disadvantage over major developing economies such as China and India.
"Our trading partners with measurably worse environmental records may be the real winners when the US goes it alone with unilateral carbon regulations," it said.