This report has two objectives. First, it presents the U.S. Environmental Protection Agencyâ??s (EPAâ??s) baseline forecast of methane emissions from the major anthropogenic sources in the U.S., and EPAâ??s cost estimates of reducing these emissions. Emission estimates are given for 1990 through 1997 with projections for 2000 to 2020. The cost analysis is for 2000, 2010, and 2020. Second, this report provides a transparent methodology for the calculation of emission estimates and reduction costs, thereby enabling analysts to replicate these results or use the approaches described herein to conduct similar analyses for other countries. Chapter 5: "EPA estimates 1997 U.S. methane emissions from livestock manure management at 17.0 MMTCE (3.0 Tg), which accounts for ten percent of total 1997 U.S. methane emissions (EPA, 1999). The majority of methane emissions come from large swine (hog) and dairy farms that manage manure as a liquid. As shown below in Exhibit 5-1, EPA expects U.S. methane emissions from livestock manure to grow by over 25 percent from 2000 to 2020, from 18.4 to 26.4 MMTCE (3.2 to 4.6 Tg). This increase in methane emissions is primarily due to the increasing use of liquid and slurry manure management systems which generate methane. This use is associated with the trend toward larger farms with higher, more concentrated numbers of animals." - from summary
