News Summary Archives

Archean Methane Cycling and Life’s Co-Evolution: Intertwining Early Biogeochemical Processes and Ancient Microbial Metabolism

By Keith Cowing

Status Report

physics.ao-ph

April 7, 2025

Filed under Archean, atmosphere, biogeochemical cycle, biosphere, Climate change, Earth, habitability, origin of life, physics.ao-ph

Archean Methane Cycling and Life’s Co-Evolution: Intertwining Early Biogeochemical Processes and Ancient Microbial Metabolism — Methane Cycle During the Archean. High-temperature magmatic processes and low-temperature gas-waterrock reactions, such as Fischer-Tropsch Type (FTT) reactions during serpentinization near hydrothermal vents, were probably the most important Archean abiotic sources of CH4. Additionally, some amount of primordial CH4 could have been released as a result of meteorite impacts. As time passed, different microbial methanogenesis pathways, including hydrogenotrophic, acetoclastic, and methylotrophic, started to contribute to Archean CH4 content. Through photochemical reactions, CH4 was converted to more complex hydrocarbons, creating a hazy atmosphere. Abiotic and biotic oxidation processes were also likely present on Precambrian Earth to consume CH4. Oxidation of CH4 could have happened through processes such as anaerobic sulfate-dependent, metal-dependent, or nitrate/nitrite-dependent anaerobic methanotrophy pathways. Aerobic methanotrophy also contributed to oxidation, likely following the evolution of oxygenic photosynthesis and the availability of O2 as an electron acceptor. — physics.ao-ph

This chapter explores the key carbon compounds that shaped the Archean biogeochemical cycle, delineating their substantial impact on Earth’s primordial atmospheric and biospheric evolution.

At the heart of the Archean carbon cycle were carbon dioxide and methane, which served as key regulators of Earth’s early climate. Particular emphasis is placed on methane cycling, encompassing both abiotic methane production and consumption, as well as their biotic counterparts-methanogenesis and methanotrophy.

These ancient microbial pathways not only shaped methane fluxes but were also tightly interwoven with Earth’s evolving redox state. We provide a comprehensive exploration of the intertwined evolution of Earth’s geochemical environment and microbial life.

The interdisciplinary approach of this chapter not only sheds light on the complex dynamics of Earth’s early methane cycling but also offers critical insights that could inform the search for life beyond our planet, thereby marking a contribution to Earth sciences, astrobiology, and related fields.

Saleheh Ebadirad, Timothy W. Lyons, Gregory P. Fournier

Comments: 27 pages, 3 figures, 3 tables, accepted for publication in “The Archean Earth” (ed.: M. Homan, P. Mason, R. Ernst, T. Lyons, C. Heubeck, D. Papineau, E. Stueeken, R. Mazumder, A. Webb, W. Altermann), Elsevier
Subjects: Atmospheric and Oceanic Physics (physics.ao-ph); Populations and Evolution (q-bio.PE)
Cite as: arXiv:2503.21919 [physics.ao-ph] (or arXiv:2503.21919v1 [physics.ao-ph] for this version)
https://doi.org/10.48550/arXiv.2503.21919
Focus to learn more
Submission history
From: Saleheh Ebadirad
[v1] Thu, 27 Mar 2025 18:54:01 UTC (820 KB)
https://arxiv.org/abs/2503.21919
Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

Follow on Twitter