Three billion years ago, the sun shone weaker, but Earth stayed surprisingly warm. Carl Sagan thought a greenhouse effect must have been to thank. A model built on 359 chemical processes has finally arrived at scenarios with a reasonable chance of producing the needed methane on ancient Earth. The model has broad parameters in hope that it may someday be of use to interpret conditions on exoplanets.
- Nature Geoscience
- NASA Postdoctoral Program, Japan Society for the Promotion of Science, NASA Astrobiology Institute, Alfred P. Sloan Foundation