On June 18, 2014, EPA officially proposed the Clean Power Plan—a rule that aims to reduce CO2 emissions from the nation’s existing fleet of fossil fuel-fired power plants. The proposal was developed pursuant to CAA §111(d), a section of the law for which there is limited regulatory precedent and no direct judicial decisions interpreting the statutory language. Any major new EPA rulemaking is bound to be controversial, and the proposed Clean Power Plan is no exception. The December issue contributes to the debate by expanding on the major issues explored during a July 14, 2014, workshop hosted by ELI and Duke University’s Nicholas Institute for Environmental Policy Solutions.