U.S. methane emissions exceed government estimates
Emissions of methane from fossil fuel extraction and refining activities in the South Central United States are nearly five times higher than previous estimates, according to researchers at Harvard University and seven other institutions. Their study, published this week in Proceedings of the National Academy of Sciences (PNAS), also suggests that the contribution from livestock operations may be twice as high as previously thought. Methane, a potent greenhouse gas, is produced through natural gas production and distribution, cattle farming, landfills, coal mining, manure management, and other anthropogenic and natural sources, though human activities are thought to contribute approximately 60 percent of the total. Overall, according to the new study, total methane emissions in the United States appear to be 1.5 times and 1.7 times higher than the amounts previously estimated by the U.S. Environmental Protection Agency (EPA) and the international Emissions Database for Global Atmospheric Research (EDGAR), respectively. The difference lies in the...