In a report published last week, the Congressional Research Service (CRS) concluded that the Clean Power Plan (CPP), if implemented, would create substantially greater declines in CO2 emissions than a business-as-usual scenario. The report, entitled U.S. Carbon Dioxide Emissions Trends and Projections: Role of the Clean Power Plan and Other Factors, found that: (i) CO2 emissions in the electric power sector have declined since 2010, while electricity generation remained constant; and (ii) although CO2 emissions in the electricity sector are expected to continue declining if current trends continue, those declines would be substantially greater if the CPP were implemented. EPA projections, for example, indicate that the CPP would reduce emissions in the electricity sector by 32% below 2005 levels by 2030, as compared to a 16% reduction in CO2 levels under its baseline scenario where the CPP is not implemented. That amounts to an additional reduction of 377 million metric tons of CO2 if the CPP is implemented.
Published just two days before the U.S. withdrew from its commitments under the Paris Agreement, and amidst ongoing litigation over the Rule that is now being held in abeyance, the report seeks to inform policymakers on current trends and future projections of U.S. GHG emissions, and to compare scenarios where the CPP is implemented versus one where it is not. The report observes that “[a] question for policymakers is whether U.S. GHG emissions will remain at current levels, decrease . . . or increase toward former (or even higher) levels.”
The report explains that CO2 emissions from the combustion of fossil fuels account for 77% of U.S. GHG emissions. The electric power sector contributes 35% of the total CO2 emissions from fossil fuel combustion, second only to the transportation sector. Historically, electricity generation and CO2 emissions have been positively correlated, but in 2010 that trend decoupled: while electricity generation remained constant, CO2 emissions from the electric power sector decreased. In 2016, electricity generation was equivalent to that in 2005, but CO2 emissions were 25% below 2005 levels.
This decrease in emissions was the result of several factors including changes in the U.S. electricity portfolio to include less coal, and more natural gas and renewables. If those trends continue, CO2 emissions in the electric power sector will continue to decrease, even in a scenario where the CPP is not implemented. “Assuming this were to occur, some might question the importance of the CPP in terms of meeting U.S. GHG emissions goals,” the report points out. But based on models from EPA, the Energy Information Administration, and other analyses by non-governmental groups, the report concludes that the “CPP would have a substantial impact on future CO2 emissions levels.”