Since the SC already ruled that CO2 could be regulated I don’t see how they rule against the EPA.
The argument is that SCOTUS specifically mentioned auto tailpipes(a mobil source), but SCOTUS didn't mention stationary sources.
EPA says CO2 is CO2, whether it comes out of a tailpipe or power plant exhaust stack. And, SCOTUS didn't specifically exclude stationary sources in their 2007 decision.