It aimed to reduce USA power industry's carbon dioxide pollution levels 32 percent below the 2005 levels by 2030.
The Sierra Club also criticized the Trump administration's decision describing the move as a "deadly mistake".
That's a strategy environmentalists say is nearly certain to fall short of what's needed.
Feds delaying Obama methane leak rule Overnight Energy: Dems take on Trump's chemical safety pick MORE confirmed his plan Monday to sign a formal proposal to repeal the Clean Power Plan, which sought a 32 percent cut in the carbon dioxide emissions of the nation's power sector. EPA has been working to repeal the CPP for months.
The documents do not explicitly indicate that the EPA will replace the Clean Power Plan. "There's only so many opportunities within a big spinning machine like that". The CPP gives states the option of choosing between either an emissions standards plan or a state measures plan to reduce emissions.
The EPA has not decided whether it will promulgate a new rule at all. "The EPA welcomes comment on the legal interpretation addressed in this proposed rulemaking".
While the Supreme Court has concluded that EPA is obligated to regulate greenhouse gases, "this administration has no intention of following the law", said McCarthy, who led the EPA when the Clean Power Plan was completed. But that was expected to coincide with bigger, broader changes - such as using more cleaner-burning natural gas, adding more renewable power projects and simply encouraging customers to do a better job turning down their thermostats and turning off their lights. They would also have the option of trading emissions rate credits with other states. Obama's EPA administrator, Gina McCarthy, called the proposal "just plain backwards".
That approach might yield modest emissions reductions and, in a perverse twist, might event have the opposite effect. He said ending the plan would take pressure off some cash-strapped utilities that still relied on coal-fired power plants.
In a competitive market, any improvement in emissions produced for each unit of energy could be overwhelmed by an increase in electrical output.
The Atlas Chemical Company Belches Smoke in 1972, before the EPA started regulating pollution.
Pruitt said the rule, enacted in 2015, "was about picking winners and losers".
A plant-specific approach doesn't have to mean modest impact.
In response to the administration's announcement, the Natural Resources Defense Council posted on Twitter that the nonprofit plans to fight the proposed rule.
A 2015 analysis found the combined health and climate benefits of the plan totalled $33 billion a year.
Trump has been touting his administration's plans to rescind the rule.
Obama enacted the plan to cap pollution from power plants.
-With assistance from Mark Chediak.