Climate Change Could Worsen ‘Mega-droughts’ in Sub-Saharan Africa

Sub-Saharan Africa has experienced extended periods of drought — some lasting 300 years — in recent millennia and could be at risk for even more severe dry spells as temperatures rise in the coming centuries, according to a new study. Reporting in the journal Science, researchers said that a detailed analysis of lake sediments in Ghana showed that severe droughts have developed every 30 to 65 years and that several centuries-long droughts occurred in the past 3,000 years, most recently from 1400 to 1750. Several recent African droughts — including one in the Sahel that killed 100,000 people in the 1960s — have been far less severe than some of the droughts in the climate record, a conclusion researchers were able to draw after studying how sharply water levels dropped in Lake Bosumtwi in Ghana. The researchers say their findings highlight the potential for devastating droughts in densely-populated West Africa as the region warms. “Clearly much of West Africa is already on the edge of sustainability, and the situation could become much more dire in the future with increased global warming,” said study co-author Jonathan Overpeck.