Researchers found a different picture when they looked at rainfall and evapotranspiration (or how much water leaves soil due to warm temperatures). The models they used showed that global climate change had increased the likelihood of a combination of high evapotranspiration combined with poor rainfall to the same severity as the recent period by at least 100-fold.
Scientists have a better understanding of the atmospheric conditions which cause the rains above the Horn of Africa to fail, and how global warming may be affecting these conditions.
When the Pacific Ocean is experiencing La Nina, trade winds increase and push warm ocean water from its eastern end to the western. The western equatorial Pacific heats up around Indonesia. This causes moist air from the ocean surface to rise and cause thunderstorms. This affects air circulation above the Indian Ocean. More moisture is drawn from the western end of the ocean to the eastern end.
Climate change is heating up the surface in the west Pacific. This amplifies the sequence of events, and increases the likelihood of poor rainfalls in East Africa when La Nina occurs.
Chris Funk, climate scientist at the University of California Santa Barbara and director of its Climate Hazards Center, explained that improved scientific understanding helped forecasters to predict the recent low rainfall in East Africa several months in advance.
He said that the current situation is "light-years" ahead of what it was in 2010, or 2016 — years before previous droughts in this region.
Phoebe Wafubwa Shikuku is a Nairobi-based adviser with the International Federation of Red Cross Red Crescent Societies. She says that policymakers in East Africa must help their communities recover more quickly from future droughts. She said that "Droughts will continue to occur." "We have to ask ourselves, how do we deal with the different impacts?"