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Clean Air Markets

Power Plant Emission Trends

EPA collects detailed sulfur dioxide (SO2), nitrogen oxides (NOX), and carbon dioxide (CO2) emission data and other information from power plants across the country as part of:

For the first time since the start of the Acid Rain Program (ARP), annual emissions of SO2 and NOX emissions are both under a million tons in 2019. The 2019 annual data show a 23 percent decline in SO2 emissions compared to 2018, a 14 percent decline in NOX emissions, an 8 percent decline in CO2 emissions, and a 13 percent decrease in Hg emissions. Additionally, ozone season NOX emissions dropped by 13% in 2019. During this time period, electric generation from these power plants decreased by 3 percent.

From 1990-2019, annual emissions of SO2 from power plants fell by 94 percent and annual emissions of NOX from power plants fell by 86 percent. In 2019, sources in both the CSAPR SO2 annual program and the ARP together emitted 0.97 million tons, a reduction of 14.8 million tons, or 94 percent, from 1990 levels. In 2019, sources in both the Cross-State Air Pollution Rule (CSAPR) NOX annual program and the ARP together emitted 0.88 million tons, a reduction of 5.5 million tons, or 86 percent, from 1990 levels.

EPA began collecting mercury and air toxics data under the Mercury and Air Toxics Standards in 2015. Additional data reports for all programs can be found in our Power Plant Data Highlights. Our Progress Reports provide a more detailed summary of our emissions reductions programs and the environmental benefits. A complete dataset for all programs is available in Air Markets Program Data (AMPD).

Download charts and a summary of EPA's emissions data.(37 K)  Get the free Excel reader

Annual Percent Change of Emissions, 1995-2019

Hover over the points on the graph to see the percentage increase or decrease.

Download data behind the map in this Excel file: Emissions Comparisons(788 K) Get the free Excel reader.

For the following figures, please select a pollutant:

Annual Sulfur Dioxide Emissions, 1990-2019


1991-1994 data are not available for Sulfur Dioxide.


1991-1994 data are not available for Nitrogen Oxides.


1990-1996 data are not available for Ozone Season Nitrogen Oxides.


1990-1994 data are not available for Carbon Dioxide.

Hover left to right over the map to see the changes before and after.