And the EPA hasn't formally adopted it with this proposal; instead, it's seeking public comment on its plan to adopt this position.
The formal rollback of that initiative, the Clean Power Plan, also will prolong uncertainty over the makeup of the USA energy mix and how much utilities must do to cut emissions generated by burning fossil fuels.
The Obama-era Clean Power Plan came about after a decade-long effort by several northeastern states, including NY and CT. In the absence of stricter federal regulations curbing emissions, many states have issued their own mandates promoting energy conservation. Coal production fell by at least 29 percent during the Obama administration.
Several environmental groups oppose the repeal and have said they plan to challenge it in federal court. He was among about two dozen attorneys general who sued to stop President Barack Obama's 2014 push to limit carbon emissions, stymieing the limits from ever taking effect. "We are committed to righting the wrongs of the Obama administration by cleaning the regulatory slate".
"Any replacement rule will be done carefully, properly, and with humility, by listening to all those affected by the rule", Pruitt said.
Dale Niezwaag, vice president of government relations for Basin Electric Power Cooperative, expects there to be some type of rule, given that the U.S. Supreme Court has said the EPA is responsible for regulating emissions.
Earlier this year, Governor Brown reaffirmed California's commitment to exceed the targets of the Clean Power Plan and the state, with one of the cleanest power grids in the country, remains on track to exceed the plan's requirements. But a trend of lower gas prices, flat power demand and swiftly declining costs for wind and solar have changed the equation. Officials said states still could make decisions to diversify their energy supplies, after the regulation is repealed.
But environmentalists and other supporters of the plan said Pruitt's cost estimates did not fully consider billions of dollars in savings from reduced medical bills that would result from steep cuts in pollution from coal.
The CPP had been challenged in court by 27 states after it was launched in 2015.
Ross Eisenberg, vice president of energy and resources policy at the National Association of Manufacturers, said in a statement: "The NAM supports a greenhouse gas policy going forward that is narrowly tailored and consistent with the Clean Air Act".
"The EPA can repeal the Clean Power Plan but not the laws of economics", Bloomberg tweeted.
Myron Ebell, head of the non-profit libertarian think tank Competitive Enterprise Institute, however, cheered the repeal as a step "designed to get the economy moving again". "Rather, the agency said it plans to seek public input on how best to cut emissions from natural-gas and coal-fired power plants".
"Anyone who cares about the well-being of our children would be running quickly in the direction of cutting fossil-fuel pollution", she says.
"This president has tremendous courage", Pruitt said Monday.