The Trump administration is expected on Tuesday to reveal its long-awaited plan to scale back an Obama-era rule designed to cut planet-warming emissions from the nation's power plants.

The proposal from the Environmental Protection Agency will reportedly hand authority to states to create their own rules for coal-fired power plants. That would give states the option to impose looser restrictions that allow utilities to emit more greenhouse gases like carbon dioxide and other pollutants — or to defer taking any action.

The measure also stands to relieve pressure on the coal industry, a sector President Donald Trump has vowed to revive. Coal miners have seen their fortunes fade as coal-fired plants retire ahead of schedule, under pressure from cheap natural gas and falling prices for renewable energy projects.

Tougher regulation under former President Barack Obama put additional stress on the coal industry by requiring power plants in some cases to undertake expensive upgrades or shut down.

Obama's signature Clean Power Plan established the first nationwide rules for carbon emissions. It set emissions goals for each state and gave them many options to reduce climate pollution, with the goal of cutting the nation's emissions by 32 percent below 2005 levels.

Trump is expected to tout his replacement for the Clean Power Plan at a rally in West Virginia on Tuesday evening. Politico first reported the broad outline last week. The New York Times and Washington Post have since reported details.

Andrew Wheeler, acting EPA chief, signed the proposal on Monday, The New York Times reported.

The new plan from Trump's EPA does not set a hard goal for nationwide emissions reductions, according to reports. It is projected to allow 12 times more greenhouse gas to be emitted over the next decade than under the Clean Power Plan, The Washington Post reported.

It reportedly asks states to focus on requiring coal plants to take steps to run more efficiently. In contrast, the Clean Power Plan allowed states to meet their goals by taking measures that would push coal out of the energy mix, including adding more solar and wind farms or converting coal plants to natural gas facilities.

The Trump plan would also give states a chance to forgo creating any new rules by allowing them to explain why they don't need to take action. It's possible that several states could pursue that option, given significant opposition to Obama's plan.

The Supreme Court delayed implementation of the Clean Power Plan while a federal court considered a lawsuit brought by more than half of U.S. states and industry stakeholders.

Trump cannot simply throw out the Clean Power Plan because the EPA has an obligation to regulate greenhouse gas emissions from power plants. That obligation is underpinned by a pair of Supreme Court rulings that recognize the EPA's authority to regulate climate-warming emissions and the agency's 2009 conclusion that those gases are a threat to public health and welfare.

"I think this is a rule designed to technically comply with the obligation the EPA is under to regulate CO2 without actually being a serious policy effort," said David Konisky, an associate professor at Indiana University's School of Public and Environmental Affairs.

The EPA's revision also allows the administration to delay taking action on climate change because environmental groups are likely to challenge the rule in court, said Konisky. It would also take several years for state-level environmental regulators to devise plans and get approval from the EPA.

Additionally, the EPA's new plan would reportedly allow states to revise rules that currently require plants to conduct environmental reviews when they make upgrades. The current process, known as New Source Review, was designed to prevent plants from making changes that lead to more pollution.

Earlier this month, the administration rolled back plans to raise fuel efficiency standards and tighten greenhouse gas limits for autos. The transportation and power sectors are the two biggest contributors to the nation's emissions, together accounting for more than half of the U.S. footprint.