New research shows that the increased frequency of drought observed in eastern Africa over the last two decades is likely to continue so long as global temperatures continue to rise. Such an eventuality increases the risk to the estimated 17.5 million people in the Greater Horn of Africa who already face potential food shortages.
The research was published in the journal Climate Dynamics by scientists from the US Geological Survey and the University of California, Santa Barbara. The USGS along with the US Agency for International Development have been identifying areas of potential drought and famine in order to ensure that food and aid reaches those people who need it most.
The research found that warming of the Indian Ocean is linked to the global warming, findings which contradict with previous scenarios created by the Intergovernmental Panel on Climate Change that were seen to predict increased rainfall in the same region.
“Global temperatures are predicted to continue increasing, and we anticipate that average precipitation totals in Kenya and Ethiopia will continue decreasing or remain below the historical average,” said USGS scientist Chris Funk. “The decreased rainfall in eastern Africa is most pronounced in the March to June season, when substantial rainfall usually occurs. Although drought is one reason for food shortages, it is exacerbated by stagnating agricultural development and continued population growth.”
The last century has seen the planet warm decade by decade, and has seen the Indian Ocean warm especially fast. A warmer Indian Ocean decreases the rainfall in eastern Africa, as all the rain has already fallen back over the ocean instead of over the land.
The scientists compiled existing datasets on temperature, wind speed and precipitation in an effort to determine what was driving the climate variations in the tropical Indian and Pacific Ocean region.
A majority of the warming in the Indian Ocean is linked to human activities, specifically greenhouse gas and aerosol emissions.
“Forecasting precipitation variability from year to year is very difficult, and research on the links between global change and precipitation in specific regions is ongoing so that more accurate projections of future precipitation can be developed,” said University of California, Santa Barbara, scientist Park Williams. “It is also important to note that while sea-surface temperatures are expected to continue to increase in the Indian Ocean and cause an average decrease in rainfall in eastern Africa, there will still occasionally be very wet years because there are many factors that influence precipitation.”