Variability in Atmospheric Methane From Fossil Fuel and Microbial Sources Over the Last Three Decades

Rona Thompson, Euan Nisbet

Research output: Contribution to journalArticlepeer-review

Abstract

Atmospheric measurements show an increase in CH4 from the 1980s to 1998 followed by a period of near-zero growth until 2007. However, from 2007, CH4 has increased again. Understanding the variability in CH4 is critical for climate prediction and climate change mitigation. We examine the role of CH4 sources and the dominant CH4 sink, oxidation by the hydroxyl radical (OH), in atmospheric CH4 variability over the past three decades using observations of CH4, C2H6, and δ13CCH4 in an inversion. From 2006 to 2014, microbial and fossil fuel emissions increased by 36 ± 12 and 15 ± 8 Tg y1, respectively. Emission increases were partially offset by a decrease in biomass burning of 3 ± 2 Tg y1 and increase in soil oxidation of 5 ± 6 Tg y1. A change in the atmospheric sink did not appear to be a significant factor in the recent growth of CH4.
Original languageEnglish
Pages (from-to)11499-11508
Number of pages10
JournalGeophysical Research Letters
Volume45
Issue number20
Early online date10 Oct 2018
DOIs
Publication statusPublished - 28 Oct 2018

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