The challenges led by Mitt Romney's Massachusetts asked the Supreme Court to review this decision and the Supreme Court accepted. In April 2007, in a 5-4 decision, the Supreme Court said that the EPA was wrong. The Supreme Court noted that under the statutes governing the regulation of motor vehicles, the EPA was required to regute any air pollutant that posed a threat to public welfare. Furthermore, the definitions of air pollutants would include green house gases and the definition of public welfare would include climate change. As such, the EPA was required to make a finding on whether green house gases did have a negative impact on the climate. Furthermore, the Court held that the Clean Air Act did not give the EPA discretion to decline to regulate a pollutant merely because the EPA thought it was unwise. Any decision against regulating would have to be based on a finding that greenhouse gases were not likely to have a negative impact on the climate or some express provision of the Clean Air Act that authorized the EPA to decline to issue regulations.
After the issuance of this decision, Congress attempted to enact climate change regulation to preempt EPA action (primarily through cap and trade proposals), but all attempts to pass such legislation betweeen 2007 and 2010 failed. While this action was taking place on Capitol Hill, the EPA was busy complying with the Supreme Court order by conducting the required study on greenhouse gases and, after concluding that study, releasing a preliminary finding for public comment.
In December 2009, in compliance with the Supreme Court's order, the EPA issued its finding (referred to by the DC Circuit as the "Endangerment Finding"). In what would only be a surprise to the climate change deniers, the EPA found that a group of six greenhouse gases did contribute to climate change. For the purpose of further regulation, the EPA converted the other five gases into a carbon dioxide equivalent.
Having made the finding that greenhouse gases were an air pollutant that did endanger the public welfare, the EPA proceeded to the next step mandated by the Supreme Court -- determining what, if any, regulations needed to be imposed on motor vehicles. In May 2010, the EPA issues its final regulations on motor vehicles (referred to by the Courts as the "tailpipe" rules.
Based on the EPA's past interpretation of the Clean Air Act, the enactment of the tailpipe rule required the EPA to also enact rules for stationary sources. Prior to issuing the tailpipe rule, the EPA issued a "timing" rule noting that any regulations for stationary sources would take effect at the same time as the rule for motor vehicles. Then in June 2010, the EPA issued its rule for stationary sources (referred to by the courts as the "transition" rule). The transition rule noted that the normal pollutant levels under the Clean Air Act (100 tons per year and 250 tons per year) would impact a substantial number of businesses and create an instant backlog. To avoid this backlog, the EPA would initially apply its rules on stationary sources only to sources emitting, respectively, 75,000 tons per year or 100,000 tons per year.
As with the previous decision agsinst regulating greenhouse gases, the decision to regulate greenhouse gases spawned a court challenge. The case was again heard by a three-judge panel of the DC Circuit (with two of the judges -- one from the majority and the dissenter --on the new panel). This time the DC Circuit issued a unanimous opinion. As this decision was issued the same week as the Supreme Court was issuing its decision on the Arizona immigration law and the Health Care law, the DC Circuit's action slipped under the radar of the national media.
The DC Circuit made several key findings.
First, the claim that there was some dissent to the consensus on climate change was not enough to overcome the requirement in current law that the EPA regulate pollutants. The law merely requires a reasonable expectation of harm, not absolue certainty. The evidence received by the EPA more than meets that standard.
Second, the EPA has correctly interpreted the Clean Air Act as requiring it to regulate stationary sources upon a determination that it is required to regulate automobiles. The potential cost of such regulation of stationary sources is not a basis for declining to regulate motor vehicles. The decision on the appropriate regulations in the Tailpipe rule was limited to considering the impact on the motor vehicle industry.
Third, the fact that other agencies can also impose regulations on fuel standards would not have authorized the EPA to decline to adopt the tailpipe rule.
Fourth, the regulations contained in the tailpipe rule are reaasonable and supported by the evidence.
Fifth, those covered by the Transition rule can't object to that rule on the basis of the decision to temporarily exempt smaller polluters from potential regulations. Any invalidity of the provisions exempting smaller polluters does not invalidate the remainder of the rule. As that exemption does not harm the larger producers, they do not have standing to challenge the exemption.
The bottom line of the DC Circuit's decision is that the actions of the EPA in regulating coal was required by the scientific evidence and merely went as far (and arguably not as far) as the law requires. Rather than usurping Congressional authority, the EPA only did what earlier Congresses had mandated. If individuals do not like these rules, the solution is to have Congress change the EPA's authority. Of course, the Obama Administration had attempted to avoid implementing these rules by seeking such change, but the Republicans blocked that change. As I noted back before the regulations were issued, the failure to pass the legislation was guaranteed to lead to regulations that the industry would not like. Three years later, the coal industry wants to blame everyone but themselves for the tough regulations that it is facing. If you know somebody in the southeast Ohio, don't let the coal industry get away with this lie.