Large releases of carbon dioxide, primarily from oceans in the Southern Hemisphere, were the main factor in ending the last Ice Age, according to a study that confirms the key role of CO2 in warming the planet. Researchers from Harvard and Oregon State University collected 80 samples from ice and sea sediment cores to reconstruct CO2 and temperature levels as the last Ice Age ended beginning about 20,000 years ago. Previously, ice cores from Antarctica showed temperatures rising on that continent before CO2 levels started to climb, leading global warming skeptics to contend that CO2 was not the main driver of warming. But the new study, published in Nature, says that Antarctica was an anomaly and that the global ice and sediment cores unequivocally show that CO2 rose first, which then sparked temperature increases of 6 degrees F. The initial trigger to the end of the Ice Age was a change in the tilt of the Earth’s axis, which warmed land masses in the Northern Hemisphere and melted Arctic Ice, releasing huge amounts of cold, fresh water that changed global ocean circulation. That in turn warmed the Southern Hemisphere, which melted sea and terrestrial ice there, releasing CO2 trapped under the ocean and land, the study said.
End of Last Ice Age Driven by Surge in CO2, Study Says
More From E360
-
FILM CONTEST WINNER
In the Yucatan, the High Cost of a Boom in Factory Hog Farms
-
INTERVIEW
In the Transition to Renewable Energy, China Is at a Crossroads
-
E360 Film Contest
In India, a Young Poacher Evolves into a Committed Conservationist
-
E360 Film Contest
The Amazon Rainforest Approaches a Point of No Return
-
Biodiversity
Shrinking Cod: How Humans Are Impacting the Evolution of Species
-
Cities
‘Sponge City’: Copenhagen Adapts to a Wetter Future
-
INTERVIEW
On Controlling Fire, New Lessons from a Deep Indigenous Past
-
Solutions
Paying the People: Liberia’s Novel Plan to Save Its Forests
-
OPINION
Forest Service Plan Threatens the Heart of an Alaskan Wilderness
-
INTERVIEW
Pakistan’s Solar Revolution Is Bringing Power to the People
-
Food & Agriculture
In Uganda, Deadly Landslides Force an Agricultural Reckoning
-
Energy
Why U.S. Geothermal May Advance, Despite Political Headwinds