NOAA: Previous Methane Studies Overestimated U.S. Oil and Natural Gas Emissions
Not only have there been no large increases in U.S. methane emissions over the last decade, but previous studies have significantly overestimated these emissions from U.S. oil and natural gas production, according to a new peer-reviewed study from the National Oceanic and Atmospheric Administration. As CIRES research scientist and study lead author Xin Lan told E&E News:
“We analyzed a decade’s worth of data and while we do find some increase in methane downwind of oil and gas activity, we do not find a statistically significant trend in the U.S. for total methane emissions.”
The study, which was conducted by researchers at NOAA’s Boulder, Colo., office in collaboration with the University of Colorado and published in Geophysical Research Letters, analyzed atmospheric methane (CH4) measurements from 20 North American sites that included both airplane and surface samples found in the NOAA Global Greenhouse Gas Reference Network (GGGRN) from 2006 to 2015. The researchers determined:
“Our estimated increases in North American ONG CH4 emissions (on average ~ 3.4 ± 1.4 % yr-1 for 2006-2015, ±σ) are much smaller than estimates from some previous studies and below our detection threshold for total emissions increases at the east coast sites that are sensitive to U.S. outflows. We also find an increasing trend in ethane/methane emission ratios which has resulted in major overestimation of oil and gas emissions trends in some previous studies.” (emphasis added)
Read the full blog post on EIDClimate.org.