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Remote Siberian Lake Holds Clues to Arctic—and Antarctic—Climate Change—(Fates…appear to be linked)
(Please note, National Science Foundation press release—Copyright concerns are nil.)
http://nsf.gov/news/news_summ.jsp?cntn_id=124565
[font face=Serif]Press Release 12-115
[font size=5]Remote Siberian Lake Holds Clues to Arctic--and Antarctic--Climate Change[/font]
[font size=4]Fates of polar ice sheets appear to be linked[/font]
[font size=3]June 21, 2012
Intense warm climate intervals--warmer than scientists thought possible--have occurred in the Arctic over the past 2.8 million years.
That result comes from the first analyses of the longest sediment cores ever retrieved on land. They were obtained from beneath remote, ice-covered Lake El'gygytgyn (pronounced El'gee-git-gin) ("Lake E"
in the northeastern Russian Arctic.
…
They show that the extreme warm periods in the Arctic correspond closely with times when parts of Antarctica were also ice-free and warm, suggesting a strong connection between Northern and Southern Hemisphere climate.
The polar regions are much more vulnerable to climate change than researchers thought, say the National Science Foundation-(NSF) funded Lake E project's co-chief scientists: Martin Melles of the University of Cologne, Germany; Julie Brigham-Grette of the University of Massachusetts Amherst; and Pavel Minyuk of Russia's North-East Interdisciplinary Scientific Research Institute in Magadan.
…
To quantify the climate differences, the scientists studied four warm phases in detail: the two youngest, called "normal" interglacials, from 12,000 years and 125,000 years ago; and two older phases, called "super" interglacials, from 400,000 and 1.1 million years ago.
According to climate reconstructions based on pollen found in sediment cores, summer temperatures and annual precipitation during the super interglacials were about 4 to 5 degrees C warmer, and about 12 inches wetter, than during normal interglacials.
The super interglacial climates suggest that it's nearly impossible for Greenland's ice sheet to have existed in its present form at those times.
Simulations using a state-of-the-art climate model show that the high temperature and precipitation during the super interglacials can't be explained by Earth's orbital parameters or variations in atmospheric greenhouse gases alone, which geologists usually see as driving the glacial/interglacial pattern during ice ages.
That suggests that additional climate feedbacks are at work.
…
The results are of global significance, they believe, demonstrating strong indications of an ongoing collapse of ice shelves around the Antarctic Peninsula and at the margins of the West Antarctica Ice Sheet--and a potential acceleration in the near future.
…[/font][/font]
http://dx.doi.org/10.1126/science.1222135[font size=5]Remote Siberian Lake Holds Clues to Arctic--and Antarctic--Climate Change[/font]
[font size=4]Fates of polar ice sheets appear to be linked[/font]
[font size=3]June 21, 2012
Intense warm climate intervals--warmer than scientists thought possible--have occurred in the Arctic over the past 2.8 million years.
That result comes from the first analyses of the longest sediment cores ever retrieved on land. They were obtained from beneath remote, ice-covered Lake El'gygytgyn (pronounced El'gee-git-gin) ("Lake E"
in the northeastern Russian Arctic.
…
They show that the extreme warm periods in the Arctic correspond closely with times when parts of Antarctica were also ice-free and warm, suggesting a strong connection between Northern and Southern Hemisphere climate.
The polar regions are much more vulnerable to climate change than researchers thought, say the National Science Foundation-(NSF) funded Lake E project's co-chief scientists: Martin Melles of the University of Cologne, Germany; Julie Brigham-Grette of the University of Massachusetts Amherst; and Pavel Minyuk of Russia's North-East Interdisciplinary Scientific Research Institute in Magadan.
…
To quantify the climate differences, the scientists studied four warm phases in detail: the two youngest, called "normal" interglacials, from 12,000 years and 125,000 years ago; and two older phases, called "super" interglacials, from 400,000 and 1.1 million years ago.
According to climate reconstructions based on pollen found in sediment cores, summer temperatures and annual precipitation during the super interglacials were about 4 to 5 degrees C warmer, and about 12 inches wetter, than during normal interglacials.
The super interglacial climates suggest that it's nearly impossible for Greenland's ice sheet to have existed in its present form at those times.
Simulations using a state-of-the-art climate model show that the high temperature and precipitation during the super interglacials can't be explained by Earth's orbital parameters or variations in atmospheric greenhouse gases alone, which geologists usually see as driving the glacial/interglacial pattern during ice ages.
That suggests that additional climate feedbacks are at work.
…
The results are of global significance, they believe, demonstrating strong indications of an ongoing collapse of ice shelves around the Antarctic Peninsula and at the margins of the West Antarctica Ice Sheet--and a potential acceleration in the near future.
…[/font][/font]
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