O n October 10, 2017, the U.S. Environmental Protection Agency (EPA) proposed to repeal the Clean Power Plan (CPP), an Obama Administration rule that would limit carbon dioxide (CO 2 ) emissions from existing fossil-fuel-fired power plants. The action came in response to Executive Order 13783, in which President Trump directed federal agencies to review existing regulations and policies that potentially burden the development or use of domestically produced energy resources. Among the E.O. 's specific directives was that EPA review the CPP, which was one of the Obama Administration's most important actions directed at reducing greenhouse gas (GHG) emissions. EPA promulgated the CPP on August 3, 2015. The rule set standards for CO 2 emissions from existing fossil-fuel-fired power plants under Section 111(d) of the Clean Air Act (CAA). Besides EPA's proposal to repeal the rule, the rule is the subject of ongoing litigation: a number of states and other entities have challenged it, while other states and entities have intervened in support of it. On February 9, 2016, the Supreme Court granted applications to stay the rule for the duration of the litigation. GHG emissions decreased substantially in 2008 and 2009 as a result of a variety of factors—some economic, some the effect of government policies at all levels. A: The U.S. electricity generation sector contributed about 29% of all U.S. GHG emissions in 2015. Statutory Authority

		Q: Under what authority did EPA promulgate the Clean Power Plan rule? The court, therefore, did not reach the question of whether the flexible approach taken by EPA for mercury controls (i.e., a cap-and-trade system) met the requirements of Section 111(d). As discussed in more detail below, in the CPP rule, EPA determined the BSER for existing power plants based on three "building blocks": (1) efficiency improvements at affected coal-fired power plants, (2) generation shifts among affected power plants, and (3) renewable generating capacity. States determine which measure they want to use to be in compliance. Although it has been widely reported that the rule would require a 32% reduction in CO 2 emissions from the electricity sector by 2030, compared to 2005 levels, this reduction was EPA's estimate of the rule's ultimate effect nationwide. The CO 2 emission reduction already achieved represents 77% of the reduction that EPA expected the electric power sector to achieve by 2030 under the CPP. Q: What are the state-specific mass-based targets? Q: How does EPA's Clean Power Plan interact with existing GHG emission reduction programs in the states, namely the Regional Greenhouse Gas Initiative and California's climate policies? A: The respective roles of actions that individual power plants take (i.e., "inside the fence" actions, such as the adoption of pollution control devices or fuel switching) versus actions by other actors, including energy consumers ("outside the fence" actions) have been the subject of much of the controversy surrounding the CPP. The final rule, as promulgated, set a deadline of September 6, 2016, for each state to submit a State Implementation Plan to EPA. The U.S. Court of Appeals for the District of Columbia heard oral arguments in the case in September 2016, but agreed on April 28, 2017, to an EPA request to hold the case in abeyance while the agency conducts the review required by Executive Order 13783. A: Although the agency has proposed to repeal the Clean Power Plan, it did not propose repeal of the GHG "endangerment finding," the 2009 agency finding that emissions of CO 2 and other GHGs endanger public health and welfare. Without addressing this finding, the agency appears to have a continuing obligation to limit emissions of CO 2 from power plants. Thus, in addition to the proposed repeal of the CPP, on December 18, 2017, EPA issued an Advance Notice of Proposed Rulemaking (ANPRM) to solicit information on whether it is appropriate to issue another rule to replace the CPP and if so, in what form and scope.
On October 10, 2017, the U.S. Environmental Protection Agency (EPA) proposed to repeal the Clean Power Plan (CPP), the Obama Administration rule that would limit carbon dioxide (CO2) emissions from existing fossil-fuel-fired power plants. The action came in response to Executive Order 13783, in which President Trump directed federal agencies to review existing regulations and policies that potentially burden the development or use of domestically produced energy resources. Among the E.O.'s specific directives was that EPA review the CPP, which was one of the Obama Administration's most important actions directed at reducing greenhouse gas (GHG) emissions.
The Clean Power Plan was promulgated in August 2015 to reduce GHG emissions from the generation of electric power. Fossil-fueled electric power plants are the largest individual U.S. sources of GHG emissions, accounting for about 29% of the U.S. total from all sources. The rule set individual state targets for average emissions from existing power plants—interim targets for the period 2022-2029 and final targets to be met by 2030. The targets for each state were derived from a formula based on three "building blocks"—efficiency improvements at individual coal-fired power plants and increased use of renewable power and natural gas combined-cycle power plants to replace more polluting coal-fired units. Although EPA set state-specific targets, states would determine how to reach these goals, not EPA.
EPA has said it would expect the rule's targets to reduce total power plant CO2 emissions by about 32% when fully implemented in 2030 as compared with 2005 levels. A variety of factors—some economic, some the effect of government policies at all levels—have already reduced power sector CO2 emissions more than ¾ of this amount as of 2016.
Although EPA is proposing to repeal the CPP, it did not propose repeal of the GHG "endangerment finding," the 2009 agency finding that emissions of CO2 and other GHGs endanger public health and welfare. Without addressing the finding, EPA appears to have a continuing obligation to limit emissions of CO2 from power plants. Thus, in addition to the proposed repeal of the CPP, EPA has issued an Advance Notice of Proposed Rulemaking (ANPRM) to solicit information on systems of emission reduction that it might require in a future rule to replace the CPP.
Besides EPA's proposal to repeal the rule, the rule is the subject of ongoing litigation in which a number of states and other entities have challenged it (while other states and entities have intervened in support of it). On February 9, 2016, the Supreme Court stayed implementation of the rule for the duration of the litigation. The U.S. Court of Appeals for the District of Columbia heard oral arguments in the case in September 2016, but agreed to an EPA request to continue to hold the case in abeyance while the agency proceeds to repeal the CPP.
This report provides background information, discusses the statutory authority under which EPA promulgated the rule, and describes the rule's current status as of November 2017. The Clean Power Plan relies on authority asserted by EPA in Section 111(d) of the Clean Air Act (CAA). This section has been infrequently used and seldom interpreted by the courts, so a number of questions have arisen regarding the extent of EPA's authority and the mechanisms of implementation.
The report also summarizes the provisions of the Clean Power Plan rule as it was finalized on August 3, 2015, including
how large an emission reduction would be achieved under the rule nationwide, how EPA allocated emission reduction requirements among the states, the potential role of cap-and-trade systems and other flexibilities in implementation, what role the actions of individual power plants (i.e., "inside the fence" actions) and actions by other actors, including energy consumers (i.e., "outside the fence" actions) might play in compliance strategies, and what role there would be for existing programs at the state and regional level, such as the nine-state Regional Greenhouse Gas Initiative (RGGI), and for broader GHG reduction programs such as those implemented in California.
The report also discusses options that Congress has to influence EPA's action.