The Clean Air Act and Power Sector Carbon Standards: Basics of Section 111(d)

In his Climate Action Plan released June 2013, President Obama called on the U.S. Environmental Protection Agency to finalize regulations controlling carbon dioxide emissions from new and existing fossil fuel­–fired power plants. The EPA recently proposed CO2 emission limits for new power plants and is preparing to fulfill its Clean Air Act mandate to issue regulations for existing power plants. These regulations will affect thousands of electricity-generating units, which contribute nearly 40% of CO2 emissions nationwide. This policy brief offers an overview of the substantive and procedural requirements for existing-source regulations and explains the regulatory timeline outlined by the president.