Global wind-shift caused Earth’s last ice age to end June 28, 2010Posted by honestclimate in Discussions.
Tags: climate change, global warming
Global wind-shift caused Earth’s last ice age to end
June 26, 2010
Washington, DC: A global shift in winds is what led to the end of Earth’s last ice age— an event that ushered in a warmer climate and the birth of human civilization.
It is believed that, in the geological blink of an eye, ice sheets in the northern hemisphere began to collapse and warming spread quickly to the south.
Most scientists say that the trigger, at least initially, was an orbital shift that caused more sunlight to fall across Earth’s northern half.
But they could not explain how the south dealt with the shift so fast.
And now a team of researchers looked for an answer towards a global shift in winds and proposed a chain of events that began with the melting of the large northern hemisphere ice sheets about 20,000 years ago.
The melting ice sheets reconfigured the planet’s wind belts, pushing warm air and seawater south, and pulling carbon dioxide from the deep ocean into the atmosphere, allowing the planet to heat even further.
Their hypothesis makes use of climate data preserved in cave formations, polar ice cores and deep-sea sediments to describe how Earth finally thawed out.
“This paper pulls together several recent studies to explain how warming triggered in the north moves to the south, ending an ice age,” said study co-author Bob Anderson, a geochemist at Columbia University’s Lamont-Doherty Earth Observatory.
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