President Obama gave his second-term global warming agenda a lot more definition Monday with a new Environmental Protection Agency chief to replace Lisa Jackson. Picking Gina McCarthy, one of her top lieutenants and the architect of some of the agency's most destructive carbon rules, is a sign he intends to make good on his vow of "executive actions" if Congress doesn't pass cap and tax.

Over the last four years running the EPA's air office, Ms. McCarthy has been a notably willful regulator, even for this Administration....