Greenland Ice Sheet Melting Can Cool Subtropics, Alter Climate
A new study finds evidence that the last time Earth was as warm as it is today, cold freshwater from a melting Greenland ice sheet circulated in the Atlantic Ocean as far south as Bermuda, elevating sea levels and altering the ocean’s climate and ecosystems.
(From Michigan News / By Jim Erickson)– The research shows a large pulse of cold freshwater covered the North Atlantic for a brief period of time about 125,000 years ago. The freshwater likely came from meltwater from the Greenland ice sheet and severely disrupted Atlantic Ocean circulation, likely killing coral reefs, flooding North America and chilling northern Europe, according to the study.
The study is published online in Paleoceanography, a journal of the American Geophysical Union. The lead author of the paper is University of Michigan climate scientist Ian Winkelstern, a postdoctoral researcher in the Department of Earth and Environmental Sciences.
The study is believed to be the first to record ocean temperature changes during this melting event that occurred during the last interglacial period, the time between the last two ice ages.
Large meltwater events like this one have occurred in Earth’s past, but they usually happen when large continental ice sheets melt at the end of an ice age. But the new study shows melting of the Greenland ice sheet alone is enough to drive large changes in ocean circulation, according to the study’s authors.
Continued melting of Greenland in the coming decades could have similar effects, such as shutting down the Gulf Stream, decimating coral reefs in Bermuda and altering the climate of northern Europe, Winkelstern said.
“If a big enough chunk of Greenland falls off, which has clearly happened in the past and has clearly caused these dramatic changes in the past, there’s no reason to think it couldn’t happen again,” he said. “We’re doing a pretty good job of melting it right now.”
Read the full article here: http://ns.umich.edu/new/releases/24549-greenland-ice-sheet-melting-can-cool-subtropics-alter-climate