for National Geographic News
The oceans surrounding Antarctica have lost some of their appetite for carbon dioxide, worrying scientists who are banking on the oceans to slow global warming, according to a new study.
They suspect stronger winds over these seas, which include parts of the Indian, Atlantic, and Pacific Oceans, are causing them to absorb less carbon dioxide, which is a greenhouse gas.
What's more, global warming and the ozone hole over the Southern Pole may be driving the fierce winds.
The oceans near Antarctica are thought to have one of the healthiest appetites for greenhouse gases.
Their surface waters can guzzle around 15 percent of all the carbon dioxide produced by people—which comes mostly from industry and automobile emissions.
The new study found the oceans are mopping up only about 10 percent of carbon dioxide—requiring projections for future levels of greenhouse gases to be bumped up accordingly.
Study lead author Corinne Le Quéré, of the Max Planck Institute for Biochemistry in Jena, Germany, and colleagues examined atmospheric carbon dioxide measurements taken from points around the world during the past 24 years.
The scientists calculated the rate of change of carbon dioxide concentrations at each of the measurement stations.
By doing so, the team was able to estimate where the main sources and "sinks"—spots such as oceans and forests that soak up large amounts of carbon dioxide—are, and how they have fluctuated over time.
(Related: "Oceans Found to Absorb Half of All Man-Made Carbon Dioxide" [July 15, 2004].)
A Modest Appetite
The researchers found carbon dioxide emissions have increased by 40 percent in the past few decades.
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