Rising global temperatures could trigger more extreme drought conditions in the coming decades in East Africa, U.S. researchers have concluded. Their findings contradict earlier research from a United Nations science panel and could have far-reaching consequences for American food aid.
The researchers, who reported their conclusions in the journal Climate Dynamics, used data spanning six decades to show that rising sea surface temperatures from emissions of human origin have created an intensification of air circulation in the Indian and Pacific Oceans, also known as the "Walker cell."
This strengthening has caused the circulation to swell westward toward the African coast, boosting heat transfer in the atmosphere and triggering greater rainfall and cloud cover over the Indian Ocean over the past 30 years.
For East Africa, this has spelled trouble — perhaps counterintuitively.
The study finds that warm and dry winds have moved west toward Africa's coast, inhibiting rainfall, particularly in parts of Kenya, Somalia and Ethiopia from March to June, one of the main growing seasons.
Chris Funk, a climatologist with the U.S. Geological Survey (USGS) and researcher at the University of California, Santa Barbara, who led the study, said in an interview that this drought pattern can be expected regularly in the future — and during both rainy seasons, they now believe.
He and co-author Park Williams, a postdoctoral researcher at U.C. Santa Barbara, have submitted follow-up results for potential publication.
'Food Insecurity More Fragile,' Report Shows
Their research will influence food aid and development funding to the estimated 17.5 million food insecure people living in the region's three most afflicted countries — Kenya, Somalia and Ethiopia — according to officials from the USAID Famine Early Warning Systems Network (FEWS NET), which funded the study.
"We take very seriously the picture this new research is painting for the Horn of Africa," Gary Eilerts, program manager of the FEWS NET, told SolveClimate News. "The situation it describes will certainly make food insecurity more fragile in the already extremely vulnerable region."
Prior research by the UN Intergovernmental Panel on Climate Change (IPCC) showed that there will be more rain over East Africa, not less.
But at least over the past two decades — and particularly since the year 2000 — dry spells in the Horn of Africa have become more severe and much more frequent, according to data collected from the NOAA Satellite and Information Service.
Droughts that once appeared every decade, now strike almost yearly, says Oxfam, the international aid group. Some estimates say precipitation has decreased by as much as 30 percent in some areas such as Sudan, over the last four decades.
The 2009 drought, the fifth consecutive one to grip East Africa, was described by Oxfam as the worst humanitarian crisis in East Africa in more than a decade.
The region's rainy seasons are critical for agricultural production and livestock management in East Africa, and water shortages are increasingly seen as an underlying trigger for armed conflict. This was the case with the Darfur conflict in Sudan, according to an 18-month study of the country by the UN Environment Program (UNEP).
Food Aid Programming Must Adapt
David Wheeler, an expert on climate and aid distribution at the Center for Global Development, a nonprofit group, said in an interview that an increase in climate-related droughts in East Africa will likely have "significant" implications for aid agencies, especially USAID, which is a major donor in the region.
In 2010, USAID donated more than $2 billion in food aid to 46 countries, and 2.1 million metric tons of food globally. A majority of the aid is dispersed across the Middle East and Africa.
Last year alone, USAID's Food for Peace program, the organization's primary food distribution program, donated nearly $700 million in aid to the three most drought-affected nations in East Africa.
James Verdin, the USGS project leader for USAID's FEWS NET, said that droughts are "the principal climatic hazard to food security issues and to countries that are dependent on subsistence agriculture and pastoralism."
Officials will have to adjust food aid budgets accordingly, he told SolveClimate News.
"As much effort as we put into providing warning, food aid is largely a humanitarian response activity. If we see a trend like the one that has been observed — and predicted — for East Africa that provides an important backdrop to year-to-year food aid programming."
Findings Contradict 2007 IPCC Report
The findings by Funk and Williams contradict what the IPCC said in its 2007 fourth assessment report about the region.
The Nobel Prize-winning panel, the UN's scientific advisory body on climate change, projected that warming oceans will result in more El Nino-like conditions globally. In contrast to the newer research, they claim that the "increased hydrologic cycle" over the Indian Ocean will move toward the East African coast and cause more rainfall.
In an interview, Isabelle Niang, a project coordinator for UNESCO's Adaption to Climate and Coastal Change in West Africa program and a coordinating lead author of the Africa chapter of the IPCC report, said the 2007 study was based on available literature at the time, but that members would "certainly take [Funk and Williams research] into consideration in the next assessment." The IPCC has begun its fifth assessment, which is scheduled for release in 2014.
But not everyone is as open to the new findings.
Richard Odingo, who works at the University of Nairobi, Kenya, and is a former vice chairperson of the IPCC, called the study "half baked" in an article published in Science and Development Network. He said IPCC's report was based on 300 years of records, while the new study used only a few decades of climate information and only from the lower atmosphere.
Verdin of USGS said the reason for the disparity is that different models were used.
Funk and Williams used a model that observed data such as temperature, wind speed and precipitation mined from East Africa data stations since 1948, whereas the IPCC mainly used climate model simulations of general global rainfall trends over three centuries.
Implications for Climate Change Adaptation
Funk agreed that his model's "focus was much more immediate, the last and next twenty years, and targeted the core growing season."
He sees enormous potential in using localized and decadal climate predictions to help better target aid allotments in drought-stricken regions worldwide. Such models could also help farming communities in these countries adapt to climate changes.
"While our research suggests more frequent droughts, these impacts could likely be largely overcome by the adoption of improved farming practices," Funk said, such as using more efficient watering systems, drought-tolerant crops and pest and watershed management.