Geological record shows climate change a constant, professor says
February 26th, 2011 Posted in Arts and LifeLOGAN — The College of Science continued its series of lectures on climate change with a lecture from geology professor Tammy Rittenour, who spoke on records of past climate change. Rittenour said that through geological evidence found all around us we can see that climate has been changing for hundreds of thousands of years.
“The biggest evidence of past climate change here in Utah is the shoreline of Lake Bonneville,” Rittenour said. “We used to be covered entirely by this massive lake in areas that are now arid desert areas. Something had to be different.”
In addition to evidence left behind by Lake Bonneville, Rittenour explained other geological evidence all around us that supports climate change. Things such as tree rings, sediments in rock, and ice cores can further explain what climate may have been like in the past and how much it has changed.
“We had mammoth right here in Cache Valley. There were mammoth tusks dug up in Hyrum,” Rittenour said. “You may have been reading Scientific American and heard about a catastrophic asteroid impact that destroyed the lives of these mammoths. You may have heard that caused them to go extinct and that it wasn’t climate change.”
Rittenour compared many current circumstances to how things were in the past to explain that things have to be different now then they were before. If climate had not changed, the world would look like it did hundreds of thousands of years ago.
Studying past climate change can help us learn about future climate change, Rittenour said. When we study past climate change we can see the natural variations in climate over a very long period of time to see what variations are normal and what is not.
Rittenour has studied ice cores that have air bubbles. These air bubbles have trapped the air from thousands of years ago and provides a sample of the atmosphere from that time Rittenour said. After studying these air bubbles and learning about the atmosphere Rittenour says that our climate and our atmosphere are not in the natural variation anymore.
“For 650,000 years Carbon Dioxide in the atmosphere has never been over three hundred parts per million until now,” Rittenour said. “Our atmosphere today is far above the natural variance of normal climate.”
Understanding past climate can help us know what to do in the future as our own climate changes Rittenour said. Evidence shows that climate has changed in the past and that is it changing now. It is changing now more than it ever has before Rittenour said.
The next lecture in the climate change series will be held March 25 in the Eccles Science Learning Center. This lecture entitled “Red trees and black beetles” will be given by entomology professor, Barbara Bentz.
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