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.