Progress Report
Emission Reductions
The Acid Rain Program (ARP) and Cross-State Air Pollution Rule (CSAPR) programs1 significantly reduced sulfur dioxide (SO₂), annual nitrogen oxides (NOₓ), and ozone season NOₓ emissions from power plants. The Mercury and Air Toxics Standards (MATS) set limits on the emissions of hazardous air pollutants from coal- and oil-burning power plants and have led to reductions in those emissions since 2010. This section covers changes in emissions at power plants affected by CSAPR, ARP, and MATS between 2021 and previous years.
- CSAPR refers to the CSAPR, the CSAPR Update, and the Revised CSAPR Update programs.
Sulfur Dioxide (SO₂) Figures
![SO₂ Emissions from CSAPR and ARP Sources, 1980–2021](img/emissions_reductions_so2_f1_small.png)
![State-by-State SO₂ Emissions from CSAPR and ARP Sources, 1990–2021](img/emissions_reductions_so2_f2_small.png)
![Comparison of SO₂ Emissions and Generation for CSAPR and ARP Sources, 2000–2021](img/emissions_reductions_so2_f3_small.png)
Annual Nitrogen Oxides Figures
![Annual NOₓ Emissions from CSAPR and ARP Sources, 1990–2021](img/emissions_reductions_nox_f1_small.png)
![State-by-State Annual NOₓ Emissions from CSAPR and ARP Sources, 1990–2021](img/emissions_reductions_nox_f2_small.png)
![Comparison of Annual NOₓ Emissions and Generation for CSAPR and ARP Sources, 2000–2021](img/emissions_reductions_nox_f3_small.png)
Ozone Season Nitrogen Oxides Figures
![Ozone Season NOₓ Emissions from CSAPR and ARP Sources, 2005–2021](img/emissions_reductions_ozone_f1_small.png)
![State-by-State Ozone Season NOₓ Emissions from CSAPR and ARP Sources, 2000–2021](img/emissions_reductions_ozone_f2_small.png)
![Comparison of Ozone Season NOₓ Emissions and Generation for CSAPR and ARP Sources, 2000–2021](img/emissions_reductions_ozone_f3_small.png)
Mercury Figures
![Mercury Emissions from MATS Sources, 2010–2021](img/emissions_reductions_mats_f1_small.png)
![State-by-State Mercury Emissions from MATS Sources, 2021](img/emissions_reductions_mats_f2_small.png)