'Seven Fat Years and Seven Lean Years'? Climate Change and Agriculture in Africa

摘要

Climate change and variability of climate are currently subject to some debate (e.g. IPCC 2001; Lomborg 2001). Despite the debate between those convinced of the reality of human-induced climate change and those who are contrarians, past impacts of climate variability, including droughts, are real for many in Africa, particularly the rural poor and those seeking an existence from rain-fed agriculture (Sokona and Denton 2001). In semi-arid and arid parts of the continent, crop yields are frequently lowered by decreases in rainfall below the average (e.g. 75 per cent of normal rainfall in parts of Southern Africa), periods of intense rainfall, and variations in temperature and soil moisture (e.g. Mendelsohn et al. 2000). Impacts, during extreme periodsas well as during periods of "normal" climate variability affect both irrigated, commercial farmers and related enterprises but also, notably, those depending on rain-fed agriculture. While one may argue that African farmers have adapted to climate variations in the past, others are suggesting (Mendelsohn et al. 2000a and 2000b) that future climate change may force large regions of marginal agriculture out of production in Africa (Devereux and Ed wards 2004).