A recently published study in Atmospheric Chemistry and Physics, co-authored by GML scientist Arlyn Andrews and supported by CPO’s Atmospheric Chemistry, Carbon Cycle and Climate (AC4) Program, uses both satellite (GOSAT) and in situ (GLOBALVIEWplus CH4 ObsPack) observations of atmospheric methane to model methane sources, removals, and trends from 2010 to 2017. Methane has a much higher heat-trapping ability than carbon dioxide, so understanding the sources and sinks of atmospheric methane is critical for predicting future climate.
Researchers found that oil and gas emissions in the United States and Canada were larger than values reported to the United Nations Framework Convention on Climate Change (UNFCCC), while coal emissions in China were lower than the inventory estimate. According to the study, from 2010-2017 oil/gas emissions increased in the United States but decreased in Europe and Canada. The model yields a global methane emission of 551 Tg a-1 averaged over 2010-2017 and a lifetime of 11.2 years.
The research highlights an effort to improve estimates of greenhouse gases and reduce uncertainties in climate models. This study demonstrates the potential for tracking greenhouse gases using atmospheric measurements, though the United States currently lacks a long-term plan for a comprehensive greenhouse gas observing system. The use of complementary in situ and satellite datasets allowed researchers to improve their estimates of methane emissions. However, expanded long-term monitoring efforts are needed to address remaining gaps in our understanding of greenhouse gases and their long-term climate impact. NOAA GML scientist Arlyn Andrews co-authored the study while GML compiled the in-situ data product used in this research, which was funded by the CPO’s AC4 program.
Read the study »