I believe that due to the myriad impacts of this transition, it is imperative that Congress take the lead in making it happen...therefore, I am leaning in favor of this decision. The EPA can certainly, and should, provide expert input to Congress given it's resources and expertise, however, it alone cannot evaluate all the ramifications of its standards....I'll cite an example from my personal link to the nuclear power industry...which by the way, needs to factor heavily into the larger Climate Change picture...
That example is Fukushima...after the 15 meter tsunami knocked out Fukushima Daiichi's power supply and reactor cooling system, three of the units failed and ended up releasing radiation to the environment. In response, the Japanese government evacuated over 100,000 local residents...including seriously ill hospital patients. They used radiation monitors and readings based on U.S. EPA standards to decide how large a region needed to be evacuated. An unfortunate ramification of this well-intended action resulted in the unnecessary and unfortunate deaths of some 1600 elderly and ill persons. If you read the attached link, you'll find that those EPA standards were set far too low, and to make a long story short, those limits, based in large measure on the Fukushima event, were subsequently raised by a significant amount (I've heard someone say 350X...note: the EPA is still reviewing their "Linear No Threshold", or LNT philosophy).
While I can't say that I agree with all the linked article's opinions on other EPA stances for other hazards (e.g. CO2), I do know that there are significant "Blind Spots" and ramifications that the EPA is not setup to consider all by itself...
Getting back to Climate Change, this is a monumental task we have in front of us...I'd like to see Congress come together...and several Senators/Representatives are doing just that...over the issue, and create new 'temporary bodies' that factor in ALL facets of the problem in order to achieve a solution...and not just rely on one agency...the EPA in this case.
Link: https://reason.com/2014/07/06/raising-the-epa-radiation-limit-will-sav/