By Sid Perkins
The rate at which oceans in the Southern Hemisphere soak up carbon dioxide from the atmosphere has slowed in recent decades, a phenomenon that could cause atmospheric concentrations of the planet-warming greenhouse gas to increase even faster than had been expected.
Today, the atmospheric concentration of carbon dioxide is rising by about 3 parts per million each year. As the concentration of carbon dioxide in the air goes up, the amount that dissolves into the ocean should also rise, says Corinne Le Quéré, an oceanographer at the University of East Anglia in Norwich, England.