Is climate change to blame for famine in the Horn of Africa?

By Duncan Green
8 August 2011 So is famine in the Horn of Africa linked to climate change or not? The question arises whenever “extreme weather events” – hurricanes, floods, droughts – hit our TV screens. It’s impossible to answer with a simple yes or no – but here’s what we think we know so far. The current drought conditions have been caused by successive seasons with very low rainfall. Over the past year, the eastern Horn of Africa has experienced two consecutive failed rainy seasons. According to surveys of local communities, this is part of a long-term shift. Borana communities in Ethiopia report that whereas droughts were recorded every six to eight years in the past, they now occur every one to two years. Meteorological data back up the picture on temperatures: mean annual temperatures increased from 1960-2006 by 1C in Kenya and 1.3C in Ethiopia, and the frequency of hot days is increasing in both countries. Rainfall trends are less clear: according to the Intergovernmental Panel on Climate Change’s Fourth Assessment Report, there are no statistically significant trends in rainfall. However, more recent research suggests that rainfall decreased from 1980 to 2009 during the “long-rains” (March to June). The historical record does not “prove” that the current drought is directly attributable to climate change. True, there are now a few cases in which scientists have been able to estimate the extent to which man-made climate change has made a particular extreme weather event more likely, but these exercises require reliable long-term weather data that only exists for Europe and North America – no such studies as yet exist in the case of the current drought. What about the future? Globally, climate change modelling projects an increase in the frequency and severity of extreme weather events like droughts and floods. In the absence of urgent action to slash global greenhouse gas emissions, temperatures in the region will probably increase by 3C-4C by 2080-99 relative to 1980-99. But again, rainfall projections are unclear. Most modelling, as reflected in the IPCC’s last assessment, suggests more rain will fall in the east Africa region as a whole, with an increase in “heavy events” (sudden downpours, so more flood risk). However, some recent studies suggest rainfall will decrease, particularly in the long rains. The combination of higher temperatures and more unpredictable rains is alarming for food production. One recent estimate published by the Royal Society suggests much of east Africa could suffer a decline in the length of the growing period for key crops of up to 20% by the end of the century, with the productivity of beans falling by nearly 50%. The conclusion? Attributing the current drought directly to climate change is impossible, but in the words of Sir John Beddington, the UK government’s chief scientific adviser, in a talk at Oxfam last week, “worldwide, events like this have a higher probability of occurring as a result of climate change”. Moreover, unless something is done, the current suffering offers a grim foretaste of the future – temperatures in east Africa are going to rise and rainfall patterns will change, making a bad situation worse. […]

Is climate change to blame for famine in the Horn of Africa? via The Oil Drum