Importantly, the changes in cereal yield projected for the 2020s
and 2080s are driven by GHG - induced climate change
and likely do not fully capture interannual precipitation variability which can result in large yield reductions during
dry periods, as the IPCC (Christensen et al., 2007) states: ``... there is less confidence in the ability of the AOGCMs (atmosphere - ocean general circulation models) to generate interannual variability in the SSTs (sea surface temperatures) of the type known to affect African rainfall, as
evidenced by the
fact that very few AOGCMs produce droughts comparable in magnitude to the Sahel droughts of the 1970s
and 1980s.»