Benchmarking 2019: Emissions Down, with a Cautionary Tale

Climate and air pollution from the U.S. electric power sector continued to decline in 2017, as M.J. Bradley & Associates reported in its annual Benchmarking Air Emissions of the 100 Largest Electric Power Producers in the United States report. However, this years-long good news trend reversed in 2018, as carbon emissions from the sector increased by about one percent, largely as a result of weather-driven demand and generation from gas-fired electricity generators. With the Trump administration continuing its assault of climate action and clean energy progress in the U.S., it is more important than ever for the highest-polluting sectors of the economy, including the electric power sector, to redouble efforts to curb climate pollution to get on track towards achieving domestic and international decarbonization goals. Only if they do more can we be protected from the growing climate danger.

Climate and Air Pollution Continue to Decline with Clean Energy Leadership as a Key Driver

The electric power sector has made significant progress in reducing emissions of NOx and SO2. From 2000 to 2018, NOx and SO2 emissions declined 80 and 89 percent, respectively. Over the same period, climate pollution (CO2) declined approximately 21 percent. Generation from renewable sources, including hydroelectric, wind, solar, geothermal, and other renewable sources, doubled during this time and acted as a principal driver of the downward trend in climate and air pollution. Clean energy is also growing the economy, as evidenced by the 41 percent growth in GDP.

Deep Decarbonization Goals Require the Power Sector to Step Up Emissions Reductions Efforts

A number of recent studies examining the prospects of deep decarbonization of the U.S. and global economies resoundingly support the need for a steeper and more rapid decline in carbon pollution. This year’s benchmarking analysis surveys the Intergovernmental Panel on Climate Change’s (IPCC) 2018 Special Report on Global Warming of 1.5oCelsius, which finds that global carbon emissions must reach net-zero by 2050 in order to limit warming to 1.5O Celsius with limited overshoot, a level consistent with the agreement that 195 countries made in the 2016 Paris Agreement.

The International Energy Association’s (IEA) Energy Technology Perspectives 2017 also details decarbonization pathways, with two scenarios focused on the U.S. power sector. In one, the U.S. power sector meets a warming level of 2O Celsius by 2050 and in the other, the sector decarbonizes further and faster, limiting future temperature increases to 1.75O Celsius by 2100 (Note that these scenario outcomes for the power sector would not meet the  set forth by the IPCC). The IEA estimates that the emissions intensity of the U.S. power sector would have to dip to between 510 and 514 pounds per megawatt-hour (lbs/MWh) of carbon dioxide by 2030 and to a maximum of 25 lbs/MWh in 2050 in order to be on track for the outcomes of the IEA pathways. For comparison, the aggregate national average emissions intensity of the power sector was 932 lbs/MWh in 2018, based on data from EPA and EIA. Of the top 20 privately- or investor-owned power producers, carbon dioxide emission rates in 2017 ranged from 107 lbs/MWh to 1,696 lbs/MWh, as reported by MJB&A.

MJB&A points out that electric power companies in the U.S. have been actively evaluating their own decarbonization scenarios, and in some cases, incorporating representative policy implications into long-term planning efforts to understand the implications for their businesses and operations. Some forward-thinking industry leaders have announced commitments and specific strategies to reduce carbon emissions to align with these suggested emissions pathways.

The sector continues to make progress despite the ongoing efforts of the Trump administration to thwart climate progress. We’re expecting the Trump EPA to soon finalize its repeal and replacement of the Clean Power Plan, the nation’s first-ever limits on carbon pollution from power plants in operation, along with weakened emissions standards for new power plants. Contrary to expectations that the Trump rollbacks would dissuade the power sector from transitioning to clean energy, industry momentum towards investing in clean energy solutions has picked up thanks to market dynamics, strong state climate and energy policies, and increasingly, customer demand.


This year’s benchmarking data reaffirms the downward path of climate and air pollution in the power sector. These harmful emissions continue to decline driven by strong policy solutions, smart investments in clean energy and energy efficiency, market forces, company leadership and stakeholder engagement. And for another consecutive year, the benchmarking report shows that a cleaner electricity sector can support a strong and growing economy.

However, as demonstrated by the uptick in power sector emissions in 2018, this is no cause to sit back. In fact, it is time to heighten the sense of urgency. We cannot rely on market forces alone to reach long term climate and energy goals. EIA projects in its 2019 national energy forecast that power sector emissions will be 1,749 million short tons (1,587 million metric tonnes) in 2050. At this rate, the power sector will be nowhere near on track to reduce emissions on the order needed to contribute to U.S. and global decarbonization efforts. Most of the literature addressing decarbonization by mid-century reaches the consensus that the electric power sector must achieve net-zero emissions by 2050, and that this is a critical component of the overall strategy to economy-wide decarbonization.

Even while the clean energy transition is underway, the power sector must take sweeping steps to ensure consistent and steep reductions without exception in climate and air pollution over the coming decades in order to effectively contribute to achieving domestic and global decarbonization goals.

About the Authors

Starla Yeh

Director, Policy Analysis Group, Climate & Clean Energy Program

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