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Earth was a hothouse 201 million years ago, leading to the Triassic-Jurassic mass extinction event. How did it recover? Why was there no runaway greenhouse effect?
David Bortin
Whittier, California, US
A “runaway greenhouse effect” on Earth, such as the one that befell Venus long ago, would be initiated if carbon dioxide, methane and other greenhouse gases were to reach atmospheric concentrations so high (probably around 30,000 parts per million) that thermal radiation from the “hot body” planet couldn’t keep up with the influx of heat from the sun.
Earth would first become so hot as to be uninhabitable,…
