The U.S. Environmental Protection Agency, under the Trump administration, unveiled its plan Tuesdayto roll back the Clean Power Plan, seen as the centerpiece of former President Barack Obama’s effort to slow the flow of heat-trapping emissions into the atmosphere and to combat climate change. The action, which Trump is expected to promote in West Virginia on Tuesday, would undo federal emissions regulations, instead handing over power to individual states to determine how — or whether — to restrict carbon dioxide and other greenhouse gas emissions.

Brown said in a statement Tuesday that the president’s plan “will not stand. … Truth and common sense will triumph over Trump’s insanity.”

California in 2015 was one of 24 states and cities across the country to defend the Clean Power Plan, under intense scrutiny. Brown at the time said, “In the face of overwhelming scientific evidence, reckless politicians and polluters want to gut the president’s clean air plans.”

Brown has since reaffirmed what he called “California’s commitment to exceed the targets of the Clean Power Plan.”

California has some of the strictest environmental regulations in the country. The state has set a goal of reducing greenhouse gas emissions 40 percent below 1990 levels by 2030. Brown in 2015 also signed into law a plan for California to produce 50 percent of its energy from renewable sources by 2030.

The Trump administration asserts that carbon dioxide emissions will continue to fall, according to a summary from The White House obtained by The Associated Press. It argues that “this will happen legally and with proper respect for the states, unlike” the Clean Power Plan, according to the summary.

California Attorney General Xavier Becerra said the state would “vigorously defend the Clean Power Plan,” suggesting a potential future lawsuit.

It is the latest in an escalating legal battle between California and the Trump administration. Becerra has filed nearly 40 lawsuits against the federal government, including one in May to preserve Obama-era fuel efficiency standards for cars and light trucks. The Trump administration is seeking to roll back such regulations guiding fuel economy standards.

Brown called the EPA administrator an “outlaw” for the move.