Millions of people in the region required emergency food aid after the failure of two rainy seasons - the 'short rains' (typically October to December) of 2010 and 'long rains' (March to June) of 2011.
Researchers used cutting edge 'climate change attribution' techniques to quantify how the probability of these two unusually dry rainy seasons may have changed as a result of human influence on climate.
Dr. Fraser Lott, an Attribution Scientist at the Met Office and lead author on the paper, said: "We found that the particularly dry short rains in 2010 were most likely caused by natural variability. However, the chances of long rains as dry, or drier, as those of 2011 were found to have increased due to human influence."
The study used state of the art modelling techniques to see how likely the weather patterns that led to the drought were. They looked at both a world with mankind's influence on climate, as well as 'the world that might have been' without manmade greenhouse gas emissions. >> More