About 480 million years ago, the planet was a much hotter place—and we have moss to thank for the habitable Earth we enjoy today, research suggests. Back then, 16 times as much carbon dioxide existed in the atmosphere, scientists think. Some 20 million years later, carbon dioxide levels had been cut in half as the planet cooled. It may be a chemical reaction caused by moss that led to the shift, the BBC reports.
Researchers at two British universities studied today's mosses as they drew nutrients from rocks. The process, called weathering, results in the depletion of carbon dioxide in the atmosphere. A similar process may have occurred eons ago. "The humble moss has created the climate which we enjoy today, from which the life we see all around us evolved," says a researcher. Scientists had previously believed that the cooling was caused by bigger plants and trees, about 100 million years later. (Read more plants stories.)