Sub-saharan desertification and productivity are linked to hemispheric climate variability

Vegetation productivity and desertification in sub-Saharan Africa may be influenced by global climate variability attributable to the North Atlantic Oscillation (NAO) and El Niño Southern Oscillation (ENSO). Combined and individual effects of the NAO and ENSO indices revealed that 75% of the interannual variation in the area of Sahara Desert was accounted for by the combined effects, with most variance attributable to the NAO. Effects were shown in the latitudinal variation on the 200mm isocline, which was influenced mostly by the NAO. The combined indices explained much of the interannual variability in vegetation productivity in the Sahelian zone and Southern Africa, implying that both the NAO and ENSO may be useful for monitoring effects of global climate change in sub-Saharan Africa.