In the cover story of the November 11 issue of Science a team of scientists led by Scott Wing, of the Department of Paleobiology at the Smithsonian Institution, announced their finding that a period of rapid global warming 55 million years ago caused major changes in where plants grew. This sudden global warming, called the Paleocene-Eocene Thermal Maximum, or PETM, occurred in about ten thousand years, lasted for 80 to 100 thousand years, and lifted global temperatures 4-8 °C. The leaf fossils on which the report is based are the first ever discovered from the PETM interval.
Wing says that during the PETM plant ranges changed about as quickly as they did when glaciers retreated from the northern continents in the last 20,000 years. Similarly rapid changes in flora might be expected in the future as a result of human-induced global warming – if habitat destruction doesn’t block the paths by which plants disperse to their preferred climate zone.
This photo: Fossil leaf from the earliest Eocene (~55.5 million years) of the Bighorn Basin, Wyoming.
For more information, visit Mississippi to Montana: Plants Danced to Climate’s Quick Tune, a Natural History Highlight. © Smithsonian Institution