Meteorology, not emissions, helps explain an upward trend in atmospheric
methane across the US
Abstract
US natural gas production increased by ~43% between
2005 and 2015, but there is disagreement in the scientific literature on
whether this growth led to increased methane emissions. In this study,
we evaluate the possible contributions of emissions versus meteorology
to an upward trend in US atmospheric methane observations during
2007-2015. We find that interannual variability (IAV) in meteorology
yields an apparent upward trend in atmospheric methane across much of
the US. We further find that IAV in atmospheric methane at several
observation sites is correlated with IAV in local wind speed. Overall,
our results show that US trends in atmospheric methane largely reflect
variability in meteorology, and are unlikely to be a direct reflection
of trends in emissions. The results of this study therefore lend support
for the conclusion that there was little upward trend in US methane
emissions during this time.