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Clear Skies

Clear Skies Act of 2003

Information provided for informational purposes onlyNote: EPA no longer updates this information, but it may be useful as a reference or resource.
Unless otherwise noted, the data presented throughout this Web site reflect EPA’s 2003 modeling and analysis of the Clear Skies Act of 2003. Clear Skies legislation was intended to create a mandatory program that would dramatically reduce power plant emissions of sulfur dioxide (SO2), nitrogen oxides (NOx), and mercury by setting a national cap on each pollutant. The Clear Skies bill was proposed in response to a growing need for an emission reduction plan that will protect human health and the environment while providing regulatory certainty to the industry. The proposed legislation for air regulation never moved out of the Senate Environment and Public Works committee in 2005 and was therefore never enacted.

"I have sent you Clear Skies legislation that mandates a 70 percent cut in air pollution from power plants...I urge you to pass [this measure], for the good of both our environment and our economy."

- Former President George W. Bush
State of the Union, January 28, 2003

Cleaner Air, Better Health, Brighter Future

Passing Clear Skies legislation would provide immediate health benefits - emissions trading under Clear Skies provides incentives for power plants to reduce emissions early.

Clear Skies is a mandatory program that would dramatically reduce and cap emissions of sulfur dioxide (SO2), nitrogen oxides (NOX), and mercury from electric power generation to approximately 70% below 2000 levels.

Clear Skies would provide health benefits faster, more certainly and at less cost to America's consumers than would the current Clean Air Act.

Nationwide, Clear Skies would deliver unprecedented emissions reductions from the power sector without significantly affecting electricity prices for American consumers. Clear Skies would deliver certainty and efficiency, achieving environmental protection while supporting economic growth.

The mandatory emission reductions using Clear Skies' market-based cap and trade programs build on Clean Air Act programs to facilitate achievement of human health and environmental goals. Clear Skies will enable many State and local governments to meet national standards for fine particles and ozone.

Components of the Clear Skies Act

The Clear Skies Act:

  • Establishes federally enforceable emissions limits (or "caps") for all three pollutants. Clear Skies' NOx and SO2 requirements affect all fossil fuel-fired electric generators greater than 25 megawatts (MW) that sell electricity. Mercury requirements affect only the subset of these units that are coal-fired.
  • Uses a dynamic regulatory approach - emission caps and trading - that provides power plants with flexibility to reduce emissions in the least costly way.
  • Maintains the authority of state and local government to set source-specific emissions limits for sources within their borders to ensure that ambient air quality standards are met.
  Actual Emissions in 2000 Clear Skies Emissions Caps Total Reduction
First Phase of Reductions Second Phase of Reductions
SO2 11.2 million tons 4.5 million tons in 2010* 3 million tons in 2018* 73%
NOx** 5.1 million tons 2.1 million tons in 2008* 1.7 million tons in 2018* 67%
Mercury 48 tons 26 tons in 2010 15 tons in 2018* 69%

Clear Skies Provides Dramatic Benefits for Public Health

  • Clear Skies would begin delivering benefits to human health and the environment beginning with its passage. Human health benefits that EPA can quantify grow to approximately $110 billion per year by 2020, substantially outweighing the annual costs of $6.3 billion.
  • EPA projected that, by 2020, the public health benefits from Clear Skies would include 14,000 avoided premature deaths. An alternative methodology for calculating health-related benefits projects over 8,400 premature deaths prevented and $21 billion in health benefits - still far greater than the costs.
  • Americans would also experience approximately 30,000 fewer visits to the hospital and emergency room and 12.5 million fewer days with respiratory symptoms (including work loss days and school absences) each year under Clear Skies by 2020.
  • Under Clear Skies, more than 18 million additional people would be breathing air that meets the national ozone and fine particle standards in 2020. In the remaining counties, Clear Skies would achieve additional reductions in fine particles that would further protect human health.

Clear Skies Makes Great Strides to Help the Environment

  • The benefit of improvements in visibility in our national parks and wilderness areas would total $3 billion per year by 2020 and this represents only certain regions EPA can quantify.
  • Clear Skies would also:
    • Reduce nitrogen loads to the Chesapeake Bay and other waters along the East and Gulf Coasts;
    • Help lakes, streams, & forests recover from acid rain damage (including elimination of chronic acidity in Adirondack region lakes by 2030); and
    • Reduce mercury in the environment.

Clear Skies Simplifies Cumbersome Requirements and Reduces Burdens on States

  • Clear Skies would expand and strengthen a proven, mandatory market-based approach and reduce reliance on complex, less efficient requirements.
  • Clear Skies would help state and local governments attain the National Ambient Air Quality Standards (NAAQS) for fine particles (PM2.5) and ozone:
    • By 2010, an estimated 42 additional counties would meet the fine particle standard, and an estimated 3 additional counties would meet the 8-hour ozone standard.
    • By 2020, an estimated 35 additional counties would meet the fine particle standard, leaving only 8 counties nationwide out of attainment with the fine particle standard. An additional 3 counties are projected to meet the 8-hour ozone standard.

Clear Skies Maintains Energy Diversity and Security

  • Clear Skies would enable continued use of abundant domestic fuel sources.
  • Clear Skies would also benefit energy consumers by enabling power generators to continue to provide cost effective electricity for America's energy needs.

You will need Adobe Acrobat Reader, available as a free download, to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader.

Frequently Asked Questions
Clear Skies Act of 2003 Fact Sheet (PDF, 2pp., 531KB)
Clear Skies Fact Sheet [en español] (PDF,4 pp., 37KB)

* The Clear Skies Act contains "safety valve" provisions for NOx, SO2, and mercury to limit the marginal costs of removal of each of the three pollutants if costs exceed a certain threshold. The 2003 modeling, based on current technological capabilities, shows that the cost of mercury removal is expected to exceed the safety valve threshold for the Phase II cap. However, technological improvements could decrease the cost of mercury control over time and cause prices to remain below safety valve levels.

** The NOx cap is divided between two zones with separate trading programs. Zone 1 includes the 31 eastern states in the continental U.S. and eastern Texas. The emissions cap for Zone 1 is 1.58 million tons in 2008 and 1.16 million tons in 2018. Zone 2 includes the remaining states participating in the WRAP process as well as Nebraska, Kansas, Oklahoma, and some of Western Texas. The Zone 2 cap is 538,000 tons in both phases.

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