A global perspective on African climate

Publication Type  Journal Article
Year of Publication  2008
Authors  Giannini, A.; Biasutti, M.; Held, I. M.; Sobel, A. H.
Journal Title  Climatic Change
Volume  90
Issue  4
Pages  359-383
Journal Date  Oct
ISBN Number  0165-0009
Accession Number  ISI:000259186900002
Key Words  sea-surface temperature; nino southern oscillation; tropical tropospheric temperature; sub-saharan drought; el-nino; indian-ocean; rainfall variability; sahel rainfall; precipitation climatology; interannual variability
Abstract  

We describe the global climate system context in which to interpret African environmental change to support planning and implementation of policymaking action at national, regional and continental scales, and to inform the debate between proponents of mitigation v. adaptation strategies in the face of climate change. We review recent advances and current challenges in African climate research and exploit our physical understanding of variability and trends to shape our outlook on future climate change. We classify the various mechanisms that have been proposed as relevant for understanding variations in African rainfall, emphasizing a "tropospheric stabilization" mechanism that is of importance on interannual time scales as well as for the future response to warming oceans. Two patterns stand out in our analysis of twentieth century rainfall variability: a drying of the monsoon regions, related to warming of the tropical oceans, and variability related to the El Nino-Southern Oscillation. The latest generation of climate models partly captures this recent continent-wide drying trend, attributing it to the combination of anthropogenic emissions of aerosols and greenhouse gases, the relative contribution of which is difficult to quantify with the existing model archive. The same climate models fail to reach a robust agreement regarding the twenty-first century outlook for African rainfall, in a future with increasing greenhouse gases and decreasing aerosol loadings. Such uncertainty underscores current limitations in our understanding of the global climate system that it is necessary to overcome if science is to support Africa in meeting its development goals.

Notes  

348BVTimes Cited:2Cited References Count:131

URL  <Go to ISI>://000259186900002
DOI  DOI 10.1007/s10584-008-9396-y