Paleocene-Eocene Thermal Maximumsearch for term

Also called the PETM, the Paleocene-Eocene Thermal Maximum was a super-warm climate event that occured 55 million years ago. During this time, the Earth released massive amounts of greenhouse gasses and temperatures rose to the highest levels in the last 80 million years. During the PETM there was no ice on Earth. It was so warm that the poles were covered in cyprus swamps and redwood forests. The PETM is also characterized by a mass extinction of foraminifera in the deep sea.