By IANS,
Washington : Carbon dioxide released from the Antartic Ocean due to shifting wind patterns may drastically increase global warming, say scientists.
Many scientists think that the end of the last ice age was triggered by a change in earth’s orbit that caused the northern part of the planet to warm.
This partial climate shift was accompanied by rising levels of the greenhouse gas carbon dioxide, ice core records show, which could have intensified the warming around the globe.
A team of scientists at Columbia University’s Lamont-Doherty Earth Observatory now offers one explanation for the mysterious rise in carbon dioxide: the orbital shift triggered a displacement in westerly winds, which caused mixing in the Antarctic Ocean, pumping dissolved carbon dioxide from the water into the air.
“The faster the ocean turns over, the more deep water rises to the surface to release carbon dioxide,” said lead co-author Robert Anderson, geochemist at Lamont-Doherty.
“It’s this rate of overturning that regulates carbon dioxide in the atmosphere.”
“In the last 40 years, the winds have shifted south much as they did 17,000 years ago,” said Anderson.
If they end up venting more carbon dioxide into the air, man-made warming underway now could intensify, said a Columbia release.
“It (the upwelling) could well be large enough to offset some of the mitigation strategies that are being proposed to counteract rising carbon dioxide, so it should not be neglected,” he said.