Sensitivity of agricultural production to climatic change, an update
1989
Oram, P.A.
Agriculture is inherently vulnerable to climatic hazards, and many agricultural practices are aimed at reducing climatic risks. While modern technology has mitigated some suspects of weather variability, it has been unable to compensate for the progressive breakdown of traditional safeguards in tropical climates under population pressure, especially in Africa. Short-, medium-, and long-term policies involving both technical and nontechnical measures to offset climatic instability and to increase food security are indicated. Four temporal patterns of climatic change and variability are described, and geographic and strategic areas of special risk are identified. Climatic variability and secular climate shifts are the two most significant problems; the first always present, the second impending. Possible causes of increased variability include long-term climatic change, technological change, expansion of cultivation into new areas, and shifts in the geographical focus of major crops. The implication for research and policy of anthropogenically induced climatic warming are examined. Most attention has been focused on the possible effects on temperature, with not enough attention on precipitation. Soil quality and moisture-retaining capacity also need greater consideration. Laboratory studies of individual plant responses to enhanced CO2 shed little light on how increases might affect crop behavior and competition in farming systems or unmanaged ecosystems. Difficulties are foreseen in convincing policymakers of the need for current action in anticipation of long-term climatic change.
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