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BOB HIRSHON (host):
From a melt to a freeze. I’m Bob Hirshon and this is Science Update.
Melting Arctic ice may have caused the Earth’s last big freeze. This according to University of Massachusetts geoscientist Alan Condron, and University of Alaska marine scientist Peter Winsor. Condron says the start of the Younger Dryas, a twelve-hundred-year long cold period, has been attributed to meltwater that flooded the Atlantic. The question was, where did it happen?
ALAN CONDRON (University of Massachusetts, Amherst):
Our model study is one of the first to show that you have to discharge water into the Arctic first, to trigger this event.
That influx of cold, fresh water would have disrupted seawater circulation, which in turn, dramatically changed the climate. Today, Arctic ice is again melting to record lows. Condron says that because other conditions are different now, it’s unlikely to trigger a freeze, but that scientists are right to expect some kind of major consequence. I’m Bob Hirshon for AAAS, the Science Society.