When in 1968 Garrett Hardin published in the Science journal his “Tragedy of the Commons” – the dilemma in which individuals self-interestedly exploit and destroy shared resources – Africa’s Sahel region had already endured a major heat stroke in the drought of 1914. Starting in 1968, the Sahel Belt broiled in a decades-long drought that killed 100,000 people and caused the virtual extinction of its flora.
More than 20 years after the last severe drought in the over-exploited area, the news turns grim once again. The recent stroke of heat in Sahel could be a sign of devastating future “megadroughts,” as global warming continues to take its toll on climate, according to a scientific study – Atlantic Forcing of Persistent Drought in West Africa – published in Science on Thursday, Reuters reported.
Sahel – a semiarid belt of land in north Africa – forms a transitional zone between the Sahara Desert to the north and the wetter savanna to the south. While the region has sustained very dry conditions in the past, climate change threatens to scale them up.
“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 Jonathan Overpeck, co-author of the study and climatologist at the University of Arizona.
Overpeck and other scientists studied the record of droughts imprinted on sediments beneath Lake Bosumtwi in Ghana. The researchers, who gathered data dating back to 3000 years ago, found a pattern of decades-long droughts, but the ground also showed signs of centuries-long dry periods – what the study calls “megadroughts.” According to scientists, the causes of the megadroughts are still unknown, but climate change might exacerbate their effects.
“What’s disconcerting about this record is that it suggests that the most recent drought was relatively minor in the context of the West African drought history,” said Timothy Shanahan, co-author of the study.
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, a Bulgaria native, is a Chicago-based reporter for Circle of Blue. She co-writes The Stream, a daily digest of international water news trends.
Interests: Europe, China, Environmental Policy, International Security.