Chief Justice John Roberts is seen as the saving grace for climate change in a Supreme Court dominated by a staunch conservative majority, according to a top environmental group.

David Doniger, the Natural Resources Defense Council’s chief climate-change strategist, says the group's legal arguments will seek to convince Roberts when it comes to climate-change regulations, as President Trump is expected to make his decision on who replaces Justice Anthony Kennedy on Monday.

Doniger told the Economist this week that Roberts is persuadable on climate-change regulations, “if we could show that the impact of regulation was tolerable and predictable and [that] undoing them would be a mess.”

NRDC is one of the top environmental groups that sided with the Obama-era Environmental Protection Agency in defending Clean Power Plan climate regulations, which Trump's EPA is in the middle of repealing and replacing.

The Supreme Court stayed the Obama climate plan in February 2016 until all lower court action over the rules had concluded.

The D.C. Circuit Court of Appeals later held the lawsuit on the climate rule’s merits in abeyance, allowing former EPA Administrator Scott Pruitt to formulate his plan to repeal and replace the regulation.

But the ultimate trajectory of the regulations is the courts, and the Supreme Court is waiting.

No matter what EPA does, it will be sued, lawyers with a number of groups say. Even if the clean energy camp wins in a lower court, opponents will take it to the Supreme Court, and vice versa.

Many state attorneys general who sued over the Clean Power Plan have said that the Supreme Court’s 2016 stay is proof that the high court wants a crack at ruling on the Clean Power Plan.