[20201203]IF11693_农业土壤与减缓气候变化.pdf

https:/crsreports.congress.gov December 3, 2020Agricultural Soils and Climate Change MitigationPolicymakers, scientists, farmers, and other stakeholders have debated the potential of agricultural soils to sequester (store) carbon and help mitigate future climate change. This discussion includes various approaches to agriculturereferred to as carbon farming, regenerative agriculture, farming for soil health, and farming for soil carbon sequestrationand their potential to increase agricultures role as a greenhouse gas (GHG) sink and reduce its role as a GHG source. GHG sinks remove and store GHGs from the atmosphere, and GHG sources emit (release) them. Figure 1. Carbon Cycling in Agricultural Soils Source: Figure created by CRS. Agriculture: A GHG Source and Sink According to the Environmental Protection Agency (EPA), the agriculture sector is a net emitter of GHGs; agricultural practices, including crop and livestock operations, currently emit more GHGs than they remove. The EPAs annual Inventory of U.S. Greenhouse Gas Emissions and Sinks reports estimates of anthropogenic GHG emissions and sinks in the United States, using internationally standardized sectors. On the source side,