The oxygen valve on hydrogen escape since the great oxidation event

Cooke, Gregory; Marsh, Dan; Walsh, Catherine; Sainsbury-Martinez, Felix; Braam, Marrick

doi:10.5194/cp-22-483-2026

Articles | Volume 22, issue 3

https://doi.org/10.5194/cp-22-483-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/cp-22-483-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 22, issue 3

Research article

|

04 Mar 2026

Research article |

| 04 Mar 2026

The oxygen valve on hydrogen escape since the great oxidation event

Gregory Cooke, Dan Marsh, Catherine Walsh, Felix Sainsbury-Martinez, and Marrick Braam

Data sets

Varied oxygen simulations with WACCM6 (Proterozoic to pre-industrial atmosphere) Gregory Cooke et al. https://doi.org/10.5061/dryad.ncjsxksvn

Model code and software

exo-cesm/CESM2.1.3: CESM2.1.3 edits for oxygenated Earth WACCM6 simulations (Version V1) G. Cooke and G. J. Cooke https://doi.org/10.5281/zenodo.18837600

Short summary

During the Archean eon (4–2.4 Gyr ago), Earth's atmosphere lacked oxygen (O₂) but contained nitrogen, carbon dioxide, and methane. As cyanobacteria evolved, they produced O₂, while hydrogen (H) escaped, making Earth more oxidized. Around 2.4 billion years ago, O₂ levels rose, limiting hydrogen loss. Using 3D computer simulations, we found that atmospheric O₂ concentrations affect the upward diffusion of water vapor (H₂O). We therefore quantify the rate of hydrogen escape as O₂ changes.