气候变化领域集成服务门户

The United States (U.S.) Environmental Protection Agency (EPA) has established voluntary programs to reduce methane (CH4) emissions, and regulations that either directly reduce CH4 or provide co-benefits of reducing CH, emissions while controlling for other air pollutants. These programs and regulations address four sectors that are among the largest domestic CH4 emissions sources: municipal solid waste landfills, oil and natural gas, coal mining, and agricultural manure management. Over the 1993-2013 time period, 127.9 Tg of CH4 emissions reductions were attributed to these programs, equal to about 18% of the counterfactual (or potential) domestic emissions over that time, with almost 70% of the abatement due to landfill sector regulations. Reductions attributed to the voluntary programs increased nearly continuously during the study period. We quantified how these reductions influenced atmospheric CH4 concentration and global temperature, finding a decrease in concentration of 28 ppb and an avoided temperature rise of 0.006 degrees C by 2013. Further, we monetized the climate and ozone-health impacts of the CH4 reductions, yielding an estimated benefit of $255 billion. These results indicate that EPA programs and policies have made a strong contribution to CH4 abatement, with climate and air quality benefits.