Dr. Maureen Raymo is a geologist and climate scientist at the Columbia University Lamont Doherty Earth Observatory. Dr. Raymo has spent her career studying natural climate variability. The first woman to receive the acclaimed Wollaston Award, she seeks to understand how and why climate changes naturally, on timescales of hundreds of millions of years to thousands of years.
In this short video from the Yale Climate Forum, Raymo briefly explains some of the phenomena behind natural variations in Earth's climate. As Raymo explains, neither solar activity or the long term cycling of our distance and position from the sun can explain current climate change observations.
"What we're seeing right now is not natural," says Raymo.
Raymo describes our rapid rise since the start of the industrial revolution to 400 parts-per-million (ppm) of CO2 as "living in a Pliocene atmosphere" of 3 million years ago when the Earth last had this level of carbon dioxide in the air. The world was much warmer then. Due to the current, unprecedented rate of change in CO2, "the whole rest of of the climate system, the oceans are trying to catch up, the ice sheets are warming, everything's trying to catch up to this Pliocene atmosphere."
"There is this symphony going on in the climate system," says Raymo. Her and her colleagues' task is to better figure out what the Pliocene world looked like, with its 400 ppm of atmospheric CO2, to better understand the trajectory upon which we are now headed. "When everything comes to equilibrium," says Raymo, "how much of the Antarctic ice sheet will be there, will sea level have risen 10 meters, 20 meters, 30 meters."
"Historically, I can see the climate community has always underestimated the rate of change in the climate system. So..."
Image credit: blueforce4116, courtesy flickr