> Doesn't requiring operators of coal plants to produce less electricity have the effect of reducing emissions from power plants a task that was given to the EP

> Doesn't requiring operators of coal plants to produce less electricity have the effect of reducing emissions from power plants a task that was given to the EPA. Sure, along with other undesirable effects. But just as it is a mistake to decide what authority they have based on just their name, it would also be a mistake to do so based on just a one–sentence summary. We really should be quoting out of the enabling legislation. Suffice to say that this legislation is long and complex, but it specifically gives the EPA the authority to mandate design improvements to new power plants (prior to construction) so that they will operate at the best possible efficiency, and also the authority to mandate the installation of new systems to reduce the pollution put out by both existing plants and new ones. This has historically been things like scrubbers to remove pollutants from the waste stream. Think of new hardware devices that you can add to a plant or a factory that reduce the pollution while maintaining their function. The EPA tried to argue that they had devised a “system” under the meaning of the law that allowed them to shift power generation from coal to gas or renewable power. The Court pointed out that this would gut the word of all useful meaning, and that it would give the EPA the power to unilaterally decide the entire industrial policy of the country. They would be able to use the same language to simply ban almost anything they wanted, and it’s pretty clear that Congress never intended that. The EPA could use that new authority to reduce pollution by banning virtually all industrial activity, causing it all to be done in other countries, for example. There is another interesting aspect of the enabling legislation. It requires the EPA to investigate multiple systems that achieve the goal of reducing some specific pollutant from some specific source (such as soot from a power plant or whatever), then to determine how much reduction the best of those systems would achieve. Then instead of mandating that everyone has to install that specific system, they are allowed to mandate that everyone must achieve the same reduction by some means. This gives the operators a chance to beat the EPA on either cost or performance, and avoids forced mistakes. If the EPA accidentally selects the second–best system rather than the best, nobody is forced to use a sub–par means of reducing the pollutant. However, in the case of the EPA’s new generating–shifting “system”, everybody would be required to participate in the same way for it to work. The opinion states: “By contrast, and by design, there is no control a coal plant operator can deploy to attain the emissions limits established by the Clean Power Plan.” You should at least read the six–page syllabus to the opinion: https://www.supremecourt.gov/opinions/21pdf/20-1530_n758.pdf https://www.supremecourt.gov/opinions/21pdf/20-1530_n758.pdf