'We don't have to watch it happen'

The steady warming of the Indian Ocean is wicking rainfall away from Africa, exacerbating problems for the famine-prone regions on the eastern side of the continent, according to an analysis from a team of researchers that includes Scripps Institution of Oceanography at UC San Diego hydrologist Mike Dettinger.

A trend that has seen rainfall diminish in east Africa by 15 percent in recent decades is expected to continue, said the researchers, and could create an inadequate food supply for some 62 million people beyond the 123 million Africans already considered malnourished by the United Nations Food and Agriculture Organization. The researchers point out, however, that relatively simple improvements to farming practices could avert this catastrophe.

“This is a pretty dire prediction of the future if we do nothing,” said Dettinger, a U.S. Geological Survey researcher based at Scripps.

Sea surface temperatures in the Indian Ocean are at their highest levels in 120,000 years. The team led by UC Santa Barbara climate scientist Chris Funk found that an ongoing warming trend there disrupted onshore moisture transports. Instead of reaching agricultural regions in east and south Africa that are especially rain-dependent because of a lack of aqueducts, dams, and other infrastructure, more rain now falls over the ocean.

The comparison of rainfall and agricultural capacity trends appears in the paper “Warming of the Indian Ocean threatens eastern and southern Africa, but could be mitigated by agricultural development” published in the Aug. 12 issue of the Proceedings of the National Academy of Sciences.

Rapid population growth compounds the problems posed by diminishing rainfall, but the report’s authors say that simple changes ranging from water conservation strategies to the planting of more drought-tolerant crops — and the financial investments needed to make those happen — could not only prevent widespread starvation but actually decrease it.

“We don’t have to sit there and watch it happen,” said Dettinger. “What we find is that a relatively modest increase in productivity could overcome it.”

— Robert Monroe