Urban areas across the U.S. are undercounting methane emissions

Researchers from Harvard, Boston University, the Environmental Defense Fund, and NOAA/ESRL, funded in part by CPO’s Atmospheric Chemistry, Carbon Cycle, & Climate (AC4) program, have found that top-down, atmospheric measurement-based estimates of natural gas emissions across US cities are 2 to 10 times higher than estimates from current bottom-up emission inventories; and, that current policy aimed at curbing emissions at the pipeline level may not effectively mitigate future methane concerns. Published this week as an early online release in the Proceedings of the National Academy of Science (PNAS), their research draws on 8 years of emissions monitoring in the Boston urban region and analyses of emission studies across the US.