THE UNIVERSITY SEMINARS
SIXTY-NINTH ANNUAL DINNER MEETING
WEDNESDAY, APRIL 3rd, 2013
Reception at 6, Dinner at 7
THE TANNENBAUM LECTURE
What Drives Ice Ages?
WALLACE S. BROECKER
TANNENBAUM-WARNER AWARD
For Distinguished Service to the University Seminars
PETER V. NORDEN
Please RSVP by March 25 by phone or email
Parking requests by March 27
All Seminar Members and guests, and their family and friends are welcome.
ABSTRACT
Variations in climate experienced by the earth over the last 800,000 years have been paced by cyclic change in the earth’s orbit. But the response of the system to this forcing has been multifaceted involving reorganizations of ocean circulation, uptake and release of CO2 by the ocean, and shifts in the tropical rainbelts in response to a N-S sea ice ‘seesaw’. Seasonality has played a surprisingly large role. Mountain glaciers in temperate regions have responded to changes in summer warmth dominated by CO2. By contrast, winter sea ice extent in the polar region dominates shifts in the location of the earth’s tropical rainbelt. The lessons we have learned from these past changes are instructive regarding what is to be expected as fossil fuel CO2 warms the world.
