Interpreting contemporary trends in atmospheric methane

TLDR

Atmospheric methane is a key climate driver, yet its recent trends (1982‑2017) have been puzzling, with conflicting hypotheses about sources and sinks. The study aims to interpret contemporary methane trends by addressing fundamental questions about source attribution. Observations show methane increased from 1982‑2000, stabilized 2000‑2007, and rose again 2007‑2017.

Abstract

Atmospheric methane plays a major role in controlling climate, yet contemporary methane trends (1982-2017) have defied explanation with numerous, often conflicting, hypotheses proposed in the literature. Specifically, atmospheric observations of methane from 1982 to 2017 have exhibited periods of both increasing concentrations (from 1982 to 2000 and from 2007 to 2017) and stabilization (from 2000 to 2007). Expansions for the increases and stabilization have invoked changes in tropical wetlands, livestock, fossil fuels, biomass burning, and the methane sink. Contradictions in these hypotheses arise because our current observational network cannot unambiguously link recent methane variations to specific sources. This raises some fundamental questions: (