History Repeats Itself—and Sometimes So Does Climate
Hönisch, who uses forams to reconstruct climate change, gave us the Paleo-Eocene Thermal Maximum as an example. It’s an event that happened about 56 million years ago when a lot of carbon dioxide was pumped into the atmosphere, causing the planet to get really warm. Hönisch reconstructed how acidic the ocean was during the PETM using foram shells, and found that the acidification then is similar to what scientists are expecting to happen by the end of this century.
But there was one big difference: During the PETM, this increase of carbon dioxide in the atmosphere happened over the course of a few thousand years. Today, humans are putting all this carbon dioxide in the atmosphere over the course of a couple hundred years.
“That tells us that what we’re doing today is really significant, and we can learn from that,” Hönisch said. “What is happening today will actually have severe consequences for the ocean.”
