Scientist links increase in greenhouse gases to changes in ocean currents

Findings released during the annual Goldschmidt Conference at the University of Tennessee, Knoxville

KNOXVILLE -- By examining 800,000-year-old polar ice, scientists increasingly are learning how the climate has changed since the last ice melt and that carbon dioxide has become more abundant in the Earth's atmosphere.

For two decades, French scientist Jérôme Chappellaz has been examining ice cores collected from deep inside the polar ice caps of Greenland and Antarctica. His studies on the interconnecting air spaces of old snow -- or firn air -- in the ice cores show that the roughly 40 percent increase of carbon dioxide in the atmosphere since the Earth's last deglaciation can be attributed in large part to changes in the circulation and biological activity of the oceanic waters surrounding Antarctica.