LONDON, UK, March 11, 2008: Scientists have long projected that areas will become more desertic in a warming world — from the Middle East through the European Riviera to the American Southwest, from sub-Saharan Africa to parts of Australia. But scientists have measured a rapid recent expansion of desert-like barrenness in the subtropical oceans, in places where surface waters have also been steadily warming.
Relatively plankton-free areas (and thus fish-free, harboring little life) in the Atlantic and Pacific Oceans around the tropics typically cover about 20 percent of the global ocean surface, but have expanded about 15 percent since 1998, according to the new study. The change was measured by tracking color differences in sea water.
The authors of the study said the change could be temporary, given the short span of observations, but it matches a slight but steady warming trend in the affected ocean regions and also matches a pattern scientists have predicted would occur under human-caused global warming. It is not clear, however, that land and sea “deserts” are growing for the same reasons. Dr. Isaac Held, a scientist who specializes in climate modeling, said “I would advise keeping them as separate issues.”