An Underground Fossil Forest Offers Clues on Climate Change

An Underground Fossil Forest Offers Clues on Climate Change

In the clammy depths of a southern Illinois coal mine lies the largest fossil forest ever discovered, at least 50 times as extensive as the previous contender. Scientists are exploring dripping passages by the light of headlamps, mapping out an ecosystem from 307 million years ago, just before the world’s first great forests were wiped out by global warming. This vast prehistoric landscape dates back to the Pennsylvanian period of the Carboniferous era, yet may shed new light on climate change today.

Such snapshots of the very distant past — tens of millions of years before the age of dinosaurs — are hard to come by. “It is extraordinarily rare to get fossil forests of any extent at all,” said Kirk Johnson, a paleobotanist at the Denver Museum of Nature and Science. “It’s usually just a few trees here and there. But here is an ancient geography — effectively unheard of.”