Summary
The global climate is rapidly warming as a function of elevated green-house gas emissions. Earth’s climate has fluctuated between periods of warming and cooling across it’s ~4.5-billion-year history. One prominent period of past global warming that is similar to what we are observing today is the Paleocene-Eocene Thermal Maximum (PETM, ~56 million years ago) – where Earth’s climate warmed, and then cooled rapidly over a ~200,000 year interval. The PETM is an excellent archive of how the Earth-system can reduce excess carbon dioxide from the atmosphere through feedbacks with the landscape. The
