In a 2012 dissent from a District of Columbia Appellate Court opinion, Supreme Court nominee Brett Kavanaugh acknowledged that “dealing with global warming is urgent and important” but that any sweeping regulatory program would require an act of Congress:

But as in so many cases, the question here is: Who Decides? The short answer is that Congress (with the President) sets the policy through statutes, agencies implement that policy within statutory limits, and courts in justiciable cases ensure that agencies stay within the statutory limits set by Congress.

Here he sounds much like the late justice Antonin Scalia, speaking for the majority in the 2014 case Utility Air Regulatory Group v. EPA:

When an agency claims to discover in a long-extant statute an unheralded power to regulate “a significant portion of the American economy” we [the Court] typically greet its announcement with a measure of skepticism.  We expect Congress to speak clearly if it wishes to assign to an agency decisions of vast “economic and political significance.”

Scalia held this opinion so strongly that, in his last public judicial act, he wrote the order (passed 5-4) to stay the Obama Administration’s sweeping “Clean Power Plan.” Such actions occur when it appears the court is likely to vote in a similar fashion in a related case.

This all devolves to the 2007 landmark ruling, 5-4, in Massachusetts v. EPA, that the EPA indeed was empowered by the 1990 Clean Air Act Amendments to regulate emissions of carbon dioxide if the agency found that they endangered human health and welfare (which they subsequently did, in 2009). Justice Kennedy, Kavanaugh’s predecessor, voted with the majority.

Will Kavanaugh have a chance to reverse that vote? That depends on what the new Acting Administrator of the EPA plans to do about carbon dioxide emissions. If the agency simply stops any regulation of carbon dioxide, there will surely be some type of petition to compel the agency to continue regulation because of the 2009 endangerment finding. Alternatively, those already opposed to it might petition based upon the notion that the science has changed markedly since 2009, with increasing evidence that the computer models that were the sole basis for the finding have demonstrably overestimated warming in the current era. It’s also possible that Congress could compel EPA to reconsider its finding, and that a watered-down version might find itself at the center of a court-adjudicated policy fight.

Whatever happens, though, it is clear that Brett Kavanaugh clearly prefers Congressional statutes to agency fiat. Assuming that he is confirmed, he will surely exert his presence and preferences on the Court, including that global warming is “urgent and important,” but it is the job of Congress to define the regulatory statutes.