As U.S. policymakers consider how to tackle the challenge of greenhouse-gas constraints, the U.K.’s approach to the problem offers instructive examples.
EPA's Winding Road
How we got here and what to expect.
67 percent compared with 1990 levels. Sources emitted 5.2 million tons of SO 2 in 2010, well below the current annual emission cap of 9.5 million tons, and already below the statutory annual cap of 8.95 million tons set for compliance in 2010. 2
• NO SIP Call: On Sept. 24, 1998, EPA finalized a rule known as the NO SIP Call, requiring 22 states and the District of Columbia to submit state implementation plans (SIPs) that address the regional transport of ground-level ozone. In 2003, EPA began to administer the NO Budget Trading Program (NBP) under NO SIP Call. The NBP was a market-based cap-and-trade program created to reduce emissions of NO x from power plants and other large combustion sources in the Eastern United States. The NBP was designed to reduce NO x emissions during the warm summer months, referred to as the ozone season, when ground-level ozone concentrations are highest.
Since the NBP began, it has successfully reduced ozone season NO emissions throughout the region. According to most recent data from the EPA 3, in 2008 NBP ozone season NO x emissions were 9 percent below the 2008 cap; 62 percent lower than in 2000 (before implementation of the NBP); and 75 percent lower than in 1990 (before implementation of the CAA).
• CAIR/CATR/CSAPR: The Clean Air Interstate Rule (CAIR) was promulgated by EPA on March 10, 2005, to reduce SO 2 and NO x emissions in 28 states across the Eastern U.S. The intent of CAIR was to reduce pollution in non-attainment areas that are affected by emissions from stationary sources. The implementing vehicle was a cap-and-trade program under which individual generators could exceed their emissions allocations, but the system as a whole was required to remain below the cap. In 2010, CAIR SO regulations replaced the Acid Rain Program in the applicable states, while non-CAIR states continued to be regulated by the Acid Rain Program.
Although the U.S. Court of Appeals for the D.C. Circuit vacated the rules in 2008, CAIR remains in place while EPA finalizes new regulations (see “From CAIR to CSAPR”) . The EPA’s latest statistics show that the program has reduced ozone concentrations by 16 to 18 percent in CAIR states, as well as improved air quality and reduced the transport of fine particulate matter (termed “PM” in the EPA standards) by as much 18 percent. 4
Figure 1 shows the significant drop in NO x emissions since the start of the NO x SIP Call and CAIR, as compared to the new targets set by the CSAPR. (Editor’s note: At this writing, EPA was considering public comments on proposed changes to its CSAPR targets for several states. The agency proposed to increase emissions budgets to “address discrepancies in unit-specific modeling assumptions.”) Prior to 2009, these states only faced ozone season caps under the NO SIP Call. With the inception of CAIR, units began running NO x control technology year round, causing the large decrease from 2008 to 2009.
Not only have these programs accomplished their goals in terms of emissions reduction;