David Grinspoon Quote
The Great Oxygenation Event was contemporaneous with one of the most severe ice ages this world has ever known, an event known to geo-nerds as the Paleoproterozoic Snowball Earth episode.* This was probably no coincidence. At the time, Earth’s climate was likely being kept above freezing by a methane greenhouse. Methane is such a powerful infrared absorber that a very small amount of it can significantly warm a planet. It is also, however, an organic molecule that is easily and eagerly consumed by oxygen. So when all that oxygen released by the cyanobacteria built up in the atmosphere, it quickly destroyed the methane greenhouse, the atmosphere suddenly became more transparent to infrared radiation, and the temperature plummeted, plunging our planet into a complete global freeze. Such a deeply frozen condition could even potentially become a permanent dead-end state for a planet like Earth.
The Great Oxygenation Event was contemporaneous with one of the most severe ice ages this world has ever known, an event known to geo-nerds as the Paleoproterozoic Snowball Earth episode.* This was probably no coincidence. At the time, Earth’s climate was likely being kept above freezing by a methane greenhouse. Methane is such a powerful infrared absorber that a very small amount of it can significantly warm a planet. It is also, however, an organic molecule that is easily and eagerly consumed by oxygen. So when all that oxygen released by the cyanobacteria built up in the atmosphere, it quickly destroyed the methane greenhouse, the atmosphere suddenly became more transparent to infrared radiation, and the temperature plummeted, plunging our planet into a complete global freeze. Such a deeply frozen condition could even potentially become a permanent dead-end state for a planet like Earth.
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About David Grinspoon
His research focuses on comparative planetology, with a focus on climate evolution on Earth-like planets and implications for habitability. He has also studied, written and lectured on the human influence on Earth, as seen in cosmic perspective.
He has published four books, Venus Revealed, which was a finalist for the Los Angeles Times book prize, Lonely Planets: The Natural Philosophy of Alien Life, which won the 2004 PEN literary award for nonfiction, Earth in Human Hands, which was named one of NPR's Science Friday "Best Science Books of 2016" and Chasing New Horizons: Inside the Epic First Mission to Pluto, co-authored with Alan Stern. He is adjunct professor of Astrophysical and Planetary Science at the University of Colorado, a former Fellow of the Institute for Cross-Disciplinary Engagement at Dartmouth College and a former Distinguished Visiting Scholar in the College of the Environment at Wesleyan University.