Solar Storms and the Faint Young Sun Paradox
Early in our planet’s history, our Sun was about 30% dimmer than it is today. Despite this, evidence for running water and the presence of life on Earth dates back more than 3 billion years. This is referred to as the “Faint Young Sun” paradox. For decades scientists have suggested various means by which greenhouse gases such as carbon dioxide and methane may have contributed to keeping the Earth’s surface sufficiently warm despite the dimmer Sun. NExSS PI Vladimir Airapetian and colleagues have recently offered an alternative hypothesis in which a more active early Sun produced superflares and coronal mass ejections that induced chemical reactions in Earth’s atmosphere leading to the buildup of significant amounts of nitrous oxide, a strongly absorobing gas that in sufficient quantities could provide the needed warming. The full story is described in a NASA press release at
http://www.nasa.gov/feature/goddard/2016/nasa-solar-storms-may-have-been-key-to-life-on-earth
and the published paper in the journal Nature Geoscience can be found at