Implications of present-day abiogenic methane fluxes for the early Archean atmosphere

Simon Emmanuel*, Jay J. Ague

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

43 Scopus citations

Abstract

During Earth's early history, greenhouse warming by atmospheric methane helped to maintain elevated surface temperatures. Here, we estimate the present-day abiogenic CH4 flux generated by mineral alteration (serpentinization) at mid-ocean ridges, volcanic emissions, and geothermal sources; in addition, we assess the impact that abiogenic methane may have had on greenhouse warming during the early prebiotic Archean. Based on estimates of the rate of seafloor spreading and the degree of serpentinization within the oceanic crust, the flux of methane generated by serpentinized fithosphere is calculated to be ∼1.35 Mt CH4 y-1, while volcanic and geothermal sources are estimated to contribute ∼0.1 and ∼0.9 Mt CH4 y-1, respectively. Furthermore, it is shown that if atmospheric CO2 partial pressures were above 0.01 bar, the present-day level of abiogenic methane production could have been sufficient to maintain above-freezing surface temperatures during the Archean. The very high temperatures (∼70°C) that have been suggested for the early Archean, however, would have required extremely high methane fluxes or, more likely, greatly elevated atmospheric CO2 levels.

Original languageAmerican English
Article numberL15810
JournalGeophysical Research Letters
Volume34
Issue number15
DOIs
StatePublished - 16 Aug 2007
Externally publishedYes

Fingerprint

Dive into the research topics of 'Implications of present-day abiogenic methane fluxes for the early Archean atmosphere'. Together they form a unique fingerprint.

Cite this