US NOx Cap and Trade Program Lowers Smog Levels in Eastern United States

15 October 2009

The existing US NO_x cap-and-trade program lowered 2008 summertime NO_x emissions from power plants and large industrial sources 62% compared to year 2000 levels and 75% lower than in 1990, according to a report released by the US Environmental Protection Agency (EPA).

State level ozone emissions in the NBP, from 1990 to 2010 (projected). Source: EPA. Click to enlarge.

Highlights of the 2008 NO_x Budget Trading Program Annual Report, covering 20 eastern states and the District of Columbia, show that:

• The reduction of NO_x has helped reduce smog levels by 10 to 14% in the NBP (NO_x Budget Trading Program) region—largely in the eastern parts of the country;

• There is a strong association between areas with the greatest reductions in NO_x emissions and downwind sites that show the greatest improvements in smog; and

• The program contributed to improvements in air quality in 97% of nonattainment areas in the east, with 85% of these areas now below the smog standard.

The NO_x Budget Trading Program is a partnership between federal and state governments to reduce the regional transport of NO_x from power plants and industry in the eastern US. This market-based cap and trade program was created to cost-effectively reduce NO_x emissions during the ozone season. This program provides facilities flexibility to choose their control options including installing control technologies, replacing existing controls with more advanced technologies, optimizing existing controls, and switching fuels. This flexibility and an active NO_x allowance market have led to near perfect compliance since the start of the program in 2003.