[20180917]IF10979_美国农业的温室气体排放和汇.pdf

https:/crsreports.congress.gov September 17, 2018Greenhouse Gas Emissions and Sinks in U.S. AgricultureAgricultural and land use activities have played a central role in the broader debate regarding energy and climate policy options in the United States and abroad. Most U.S. climate-related proposals would not require emission reductions in the agricultural sectors but rather would incentivize reductions through voluntary measures. For example, previous energy and climate legislation considered by Congress would have established a carbon offset program for domestic farm- and land-based carbon storage activities and provided for tradeable allowances from certain agricultural and land use activities. Agriculture is both a source and a sink of greenhouse gases: sources generate emissions to the atmosphere and sinks remove carbon dioxide from the atmosphere and sequester it in plants and soil. Agricultural activities are a source of greenhouse gas (GHG) emissions, but some activities can remove carbon dioxide (CO2) from the atmosphere (sinks or emissions removals). Figure 1 illustrates both GHG emissions from farming activities and carbon sequestration in agricultural soils. Agricultu