On May 9, 2024, the Environmental Protection Agency (EPA) issued a final rule imposing greenhouse gas emissions standards for fossil fuel-fired power plants under the Clean Air Act. The rule repealed the Trump-era Affordable Clean Energy Rule and established stricter emissions standards for certain new and existing coal- and natural gas-fired plants. EPA established different standards for different sub-categories of fossil fuel power plants based on plant longevity and capacity. For example, the performance standard for existing coal-fired power plants is based on a "best system of emissions reductions" of carbon capture and sequestration with a 90% carbon dioxide capture rate. A summary of the new standards for all sub-categories is available here.