How Hurricanes May Add to Global Warming New Research Shows That Hurricanes Pump More CO2 into the Air by Roiling Oceans

Article excerpt

Scientists tracking the global warming gas carbon dioxide (CO2) should look at what hurricanes do to the surface of the sea.

The ocean soaks up about a third of the CO2 coming from fossil fuel burning and forest clearance. But new research shows that hurricanes pump some of that CO2 back into the air - and could hold important implications for global warming.

Nicholas Bates at the Bermuda Biological Station For Research at Berry Beach calls this feedback effect "significant." He explains that "hurricanes, essentially, are making oceans lose CO2." This enhances the accumulation of the climate warming gas in the atmosphere. That, in turn, has impacts - that are still unclear - for forecasts of global warming. "It's another complication" among "many uncertainties" that designers of computer programs that model climate change have to take into account, Dr. Bates says.

The Bermuda Station is strategically placed to study this unexpected hurricane effect. It maintains research sites nearby in the Sargasso Sea. Records of such sea surface conditions as air and water temperatures and salinity at one site go back some 40 years.

Bates calls this "a great window on climate change in the Sargasso Sea." It provides a basis for assessing the influence of passing hurricanes. In 1995, hurricane Felix passed over the research site giving scientists an ideal opportunity to measure hurricane effects. Bates, his Bermuda colleague Anthony Knap, and Anthony Michaels with the University of Southern California in Los Angeles report their findings in the Sept. 3 issue of Nature.

They found that Felix plus two other hurricanes - Luis and Marilyn - increased summertime feedback of CO2 to the atmosphere by 55 percent. …