President Donald Trump's plan to scrap a landmark rule to cut planet-warming emissions from power plants will likely be a drawn-out process and face a thicket of legal obstacles. Trump will sign an executive order on Tuesday to overhaul the Clean Power Plan, a senior administration official told reporters. The plan regulates carbon emissions from fossil-fuel burning electricity plants — particularly those that burn coal — and gives states a framework for new standards. The rule has been challenged in court by a number of states and industry groups. It is fiercely opposed by Trump, who claims regulations put coal miners out of work, though market forces are likely more to blame for the industry's struggles. "While there's no political support in the administration for the Clean Power Plan, it's not the kind of thing you can just do away with quickly," said David Konisky, associate professor at Indiana University's School of Public and Environmental Affairs.

The EPA will start a new rule-making process to replace the Clean Power Plan, the White House official confirmed. That would include issuing its intent to revisit the rule, taking comments, releasing the new rule and then taking additional comments — a process that typically takes a year or more. Any rule that Trump's EPA writes is certain to be less stringent than former President Barack Obama's Clean Power Plan. It will almost surely draw legal challenges from environmental groups and states. The administration official acknowledged as much to reporters on Monday.

How the legal fight could play out