Colorado’s new attorney general said Wednesday the state will withdraw from a lawsuit challenging one of the Obama administration’s biggest climate change initiatives.

Democrat Phil Weiser’s announcement signaled a reversal from his predecessor, Republican Cynthia Coffman, who signed Colorado on to a multistate lawsuit seeking to roll back the Clean Power Plan.

“Instead, we’ll be on the side supporting it,” Weiser said.

Speaking at the Outdoor Retailer and Snow Show in Denver, Weiser promised other legal action to restore or retain environmental protections.

He said Colorado would join two other multistate lawsuits, one trying to block the Trump administration from rolling back tougher car mileage standards, and another that would preserve the right of individual states to impose higher mileage standards than the federal requirements.

“The rule of law requires a response to climate change. I will fight for that,” Weiser said.

Weiser took office this month after defeating Republican George Brauchler in November. Coffman didn’t run for re-election but made an unsuccessful bid for the GOP nomination for governor.

The Clean Power Plan, enacted in 2015 by President Barack Obama, would have increased federal regulation of emissions from electricity plants and promoted cleaner energy, including natural gas and solar and wind power.

Coffman decided to challenge the plan over the objection of then-Gov. John Hickenlooper, a Democrat. Hickenlooper asked the state Supreme Court to block Coffman, but the justices declined to step in.

The Clean Power Plan has been held up by court challenges, including the lawsuit that Colorado joined.

The Trump administration said in August it planned to replace the Obama rules with new ones giving states more authority to regulate existing coal power plants.

Colorado would be at least the 18th state to sue the Trump administration over mileage standards. Trump wants to freeze the national standard at 30 miles per gallon, the level mandated by the Obama administration for 2020. Trump wants to block a subsequent increase to 36 miles per gallon in 2025.

The Trump administration also wants to revoke a provision that allows California and other states to set higher mileage standards than the federal government.

Colorado adopted California’s standard in November. The Colorado Automobile Dealers Association filed a lawsuit in state court Monday challenging that action.