Abstract

Dr. Paul Geissler
US Geological Survey
Flagstaff Arizona

Friday October 5, 2007
12:00 - 1:00 pm
WIL Rm. 101

"Causes of Martian Climate Change"

ABSTRACT:

Changes in the surface albedo patterns of Mars have been documented for centuries, from telescopic observations dating from the 17th century to more recent spacecraft explorations beginning in the 1970s. Most of these changes are now known to be produced by aeolian processes, through the redistribution of dust and sand by the winds. More recently, spacecraft observations have shown that the Martian residual South Polar Ice Cap is rapidly retreating. While scientists have struggled to explain the recession of the polar ice cap, terrestrial climate change skeptics have seized upon the example of Mars to argue that global warming on Earth has an external cause. In this talk I will show that Martian global warming is an expected consequence of surface albedo changes over the last decades, producing an increase in downwelling atmospheric radiation sufficient to account for the recession of the polar ice cap.

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