What is paleo-climatology?
The climate of the Earth is constantly changing, and it is the job of paleo-climatologists to use whatever shreds of evidence they can find to piece together the turbulent history of our planet’s climatic past.
About 8,500 years ago, water temperatures around the coast of Greenland were about 10°F warmer than they are today. We know that because studies of fossil shells show certain species of warm water—loving mollusks thrived in the region during a “climatic optimum” period. It has long been thought by paleoclimatologists that during the ice ages the tropical regions of the Earth experienced very little cooling even while mid-latitude areas became icebound. More recent evidence from the fossils of temperature-sensitive organisms suggests that the equatorial regions did indeed cool down, perhaps by more than 5°F.
It was once much warmer in Oregon than it is today. In fact, tropical fruit once grew there. We know this because an Oregon teenage boy found a fossilized banana that has proven to be 43 million years old.
Scientists will use any clue they can uncover to try to reconstruct the past climate of the Earth. Now pine needles stowed away by pack rats some 30,000 years ago are yielding data. Examination of debris from pack rat middens in the western United States indicates changes in CO, levels in the atmosphere associated with the last glacial period.
Antarctica brings to mind scenes of endless icy wastelands and wind chills off the bottom of the scale, yet it once had a climate mild enough to support dinosaurs. Fossils of the 25-foot-long meat-eating Cryolophosaurus ellito have been exhumed only 400 miles from the South Pole. Thus, 200 million years ago, the climate was mild enough to support plants and animals necessary to feed the dinosaur.