Malaria kills between one million and three million people in sub-Saharan Africa every year, most of them children. Disease outbreaks, which also include meningitis and dengue, have only recently been linked to variations in rainfall: more rain or drought can bring harsher epidemics. Using this understanding, scientists at Columbia University’s International Research Institute for Climate and Society (IRI) several years ago piloted an early-warning system to forecast where the most devastating outbreaks will likely occur. Already the system has helped reduce cases of malaria in countries such as Botswana, Colombia and Senegal.

Now the IRI has received $900,000 from to map emerging diseases in East Africa, focusing first on Ethiopia where almost two thirds of the population lives in epidemic-prone regions. By tracking where outbreaks frequently recur and overlaying predictions about rainfall patterns for the upcoming season, scientists can determine where the worst epidemics may be and give local people sufficient time to distribute antimosquito bed nets, initiate spray campaigns, and provide drugs and vaccines.

Predicting weather patterns will never be 100 percent accurate, says Stephen Zebiak, director of IRI. Mapping hotspots, however, can help reduce the spread of these killers and save countless lives.

Note: This article was originally printed with the title, "Forecasting Malaria".