April 5 th , 2012. Shake It Off: Earth's Wobble May Have Ended Ice Age The last big ice age ended about 11,000 years ago But the Antarctic was getting warmer even before CO 2 levels went up. So which came first in the Antarctic, warming or CO 2 ?
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Shake It Off: Earth's Wobble May Have Ended Ice Age
The last big ice age ended about 11,000 years ago
But the Antarctic was getting warmer even before CO2 levels went up. So which came first in the Antarctic, warming or CO2?
About 20,000 years ago, the Earth wobbled (?) on it’s access. The wobble lead to more melting of ice in the northern latitudes due to more summer insolation (Arctic & Greenland).
Fresh water into the North Atlantic, but it didn’t sink and thus shut down the ocean conveyer belt (?)
Warm water lead to increased Antarctic temperatures and this lead to a CO2 increase in the atmosphere which lead to runaway greenhouse effect worldwide (?)
"The CO2 increase turned what initially was a Southern Hemisphere warming into a global warming. That's a very nice sequence of events to explain what happened between about 19,000 and 11,000 years ago,“ Eric Wolff (a climate scientist at the British Antarctic Survey ) says.
But that's a process that has taken about 8,000 years. And Jeremy Shakun's (a NOAA post-doc at BU/Harvard) research found that the amount of CO2 it took to end the ice age is about the same amount as humans have added to the atmosphere in the past century.
Pollution Playing A Major Role In Sea Temperatures
The Atlantic Ocean, especially the North Atlantic, is peculiar: Every few decades, the average temperature of surface water there changes dramatically.
Surface temperatures around the Atlantic influence the amount and timing of rainfall in West Africa and the Amazon in South America, and whether there's drought there. They affect the number and strength of Atlantic hurricanes and even where hurricanes go.
Scientists want to know why that is, especially because these temperature shifts affect the weather. New research suggests that human activity is part of the cause.
The cause isn't in the water; it's above it — a kind of air pollution called aerosols.
The more aerosols you have, the more places there are for water vapor to condense. And so what do aerosols do (?)
"If you combine the role of volcanic activity and the human emissions of aerosols, we account for 76 percent of the total variation in sea surface temperature in our study," Ben Booth (a climate scientist at Britain's Met Office Hadley Center) says. That's a huge amount.
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