Fifty-six million years ago, about 10 million years after the dinosaurs went extinct, something strange happened to our planet.
It got hot.
Hotter than it had ever been since the Earth formed a few billion years earlier.
Carbon signatures in the geological record show that global temperature surged 5 to 8 degrees Celsius within 10,000 years.
They also indicate that the planet’s temperature remained elevated for an additional 170,000 years before returning to normal.
Scientists describe this (relatively) rapid rise in temperature as a “hypothermal event,” and it is not the only one that has ever occurred.
About 2 million years later,...