Len Mills tells us of a study showing past climate change was caused not by atmospheric carbon dioxide but by changed ocean circulation releasing heat into the atmosphere.
Most of the concerns about climate change have focused on the amount of greenhouse gases that have been released into the atmosphere, but in a new study published in Science, a group of Rutgers researchers have found that circulation of the ocean plays an equally important role in regulating the earth’s climate.
In their study, the researchers say the major cooling of Earth and continental ice build-up in the Northern Hemisphere 2.7 million years ago coincided with a shift in the circulation of the ocean—which pulls in heat and carbon dioxide in the Atlantic and moves them through the deep ocean from north to south until they’re released in the Pacific.
The ocean conveyor system, Rutgers scientists believe, changed at the same time as a major expansion in the volume of the glaciers in the northern hemisphere as well as a substantial fall in sea levels. It was the Antarctic ice, they argue, that cut off heat exchange at the ocean’s surface and forced it into deep water. They believe this caused global climate change at that time, not carbon dioxide in the atmosphere.
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