"The Influence of Land Surface Changes, Natural and
Climatic Change in West Africa"
The Sahel has long been of interest in the context of
anthropogenic impact on
climate ever since the late Jule Charney hypothesized that the 1970s
drought was caused by intensive grazing. He suggested a mechanism which
involved the impact of surface albedo on regional climate. The regional
has now sustained a period of arid conditions since the late 1960s and the
causes and implications of this change are commonly the subject of
considerable controversy. This talk examines the overall issue of
climatic change in the Sahel and looks in greater detail at hypotheses
concerning the impact of land-surface processes on regional climate. In
particular, the albedo hypothesis is challenged and the possible role of
increased atmospheric aerosol loading is considered. Implications of this
for global change are also discussed.