Analysis of Strategies for Reducing Multiple Emissions from Electric Power Plants: Sulfur Dioxide, Nitrogen Oxides, Carbon Dioxide, and Mercury and a Renewable Portfolio Standard - Table 4. National Energy Modeling System Energy Activities

Table 2. 1990 and 1997 Emissions Levels, Reference Case Projections for 2008,
and Assumed Emissions Caps for Electricity Generators

Target	NO_x (Thousand Tons)	SO₂ (Thousand Tons)	CO₂ (Million Metric Tons Carbon Equivalent)	Hg (Tons)
1990 Level	6,663	15,909	475	NA
1997 Level	6,191	13,090	533	52
2008 Reference Case Level	4,310	9,940	674	46
Emissions Caps	1,548	3,273	440/475^a	5
^aTwo alternative CO₂ emissions targets are used: 1990 level (475 million metric tons carbon equivalent) and 1990-7% level (440 million metric tons carbon equivalent). NA = not applicable. Note: The EPA’s 1997 mercury report to Congress estimated that the power sector produced 51.8 tons of mercury in the 1994-1995 period, and this value is used here as representative of emission levels in 1997. Actual 1990 and 1997 values are not available. See Environmental Protection Agency, Mercury Study Report to Congress, EPA-452/R-97-003 (Washington, DC, December 1997). Source: 1997 levels from U.S. Environmental Protection Agency, National Air Pollutant Emission Trends, 1900-1998, EPA-454/R-00-002 (Washington, DC, March 2000).