(Source) I.     Background  In 1970, with the establishment of the Environmental Protection Agency (“EPA”), Congress enacted the Clean Air Act (“CAA”), which marked the first step towards federal regulation of air pollution. Section 111(d) of the CAA authorized the EPA to regulate greenhouse gas emissions from existing power plants. Based on this provision, the Obama administration and the EPA promulgated the Clean Power Plan (“CPP”) in 2015, which assigned individual targets to each state for reducing carbon dioxide emissions from existing power plants. However, due to concerns that the CPP transcended the EPA’s mandate under the CAA and intruded states’ rights to regulate electric power, the Supreme Court stayed its implementation.  In 2019, under the Trump administration, the EPA repealed the CPP before it could take effect. Instead, it issued a weaker Affordable Clean Energy Rule (“ACE”), which directed states to “set standards of performance for each plant, essentially allowing plants to decide the amount of pollution to emit.” The EPA’s own data revealed that the ACE may result in increased carbon emissions because it “created incentives to burn more fossil fuels.” Two years later, in January 2021, the D.C. Circuit Court vacated the ACE rule while holding that [read more]