Horn Of Africa Is Drying Much Faster As Climate Warms
The Horn of Africa has become increasingly arid in sync with the global and regional warming of the last century and at a rate unprecedented in the last 2,000 years, according to new research led by a University of Arizona geoscientist.
The region has suffered deadly droughts every few years in recent decades.
The scientists suggest as global and regional warming continues, the eastern Horn of Africa, which includes Somalia, Djibouti and Ethiopia, will receive progressively less rain during the crucial “long rains” season of March, April and May.
Such a trend could exacerbate tensions in one of the most geopolitically unstable regions in the world.
The team’s suggestion that the Horn of Africa will become even drier contradicts the global climate models that indicate future warming will bring more rain to the region.
“What we see in the paleoclimate record from the last 2,000 years is evidence that the Horn of Africa is drier when there are warm conditions on Earth, and wetter when it is colder,” said lead author Jessica Tierney, a UA associate professor of geosciences.
“The rate of the recent drying in the Horn of Africa is unprecedented in the last 2,000 years,” Tierney said.
In their paper, the scientists call for researchers to develop more computer models of climate that focus on the regional scale. Such models might better predict how future warming will affect the Horn of Africa’s seasonal rains.
Study co-author Peter deMenocal said, “The region is drying in sync with carbon emissions. This has significant socioeconomic implications for this geopolitical hotspot into the future.” The Center for Climate and Life at Columbia University’s Lamont-Doherty Earth Observatory is headed by deMenocal.
The researchers used cores of ancient marine sediments from the nearby Gulf of Aden to reconstruct regional temperature and aridity for the past 2,000 years.
The team found their reconstructions of local temperature and aridity were in step with an independent reconstruction of Northern Hemisphere temperatures stretching back to the year A.D. 1. All the data point to the Horn of Africa becoming warmer and drier in the last 100 years.
The team’s report, “Past and future rainfall in the Horn of Africa,” was published online today in the open-access journal Science Advances. Co-author Caroline Ummenhofer is at Woods Hole Oceanographic Institution in Massachusetts. The National Science Foundation funded the research.