This study applied at the farm level in Tunisia aims at understanding the effects of climate change on agricultural productivity and income in Africa. Possible future climates are presented through different climate scenarios. The latter combines three levels of increasing temperature (1°centigrade (C), 2°C, and 3°C) with two levels of decreasing precipitation (10 and 20 percent) and a doubling of carbon dioxide concentration in the atmosphere (350 to 700 parts per million). The farming system of production is replicated through a bioeconomic model; that is, one that couples a cropping system model and an economic model run sequentially. The study reveals that land productivity and farm income decline under climate change. Depending on the changes in precipitation, farm productivity falls by 15 to 20 percent and farm income 5 to 20 percent when the temperature increases moderately (1°C). As the climate warms up (2°C and 3°C), farm productivity and income are severely affected, by 35 to 55 percent and 45 to 70 percent, respectively. When simple adaptation strategies based on new management techniques for hard wheat are tested - more irrigation and fertilization - compensations for the negative effects of climate change are found to be worthwhile only for a 1°C increase in temperature. However, the success of adaptation strategies highly depends on the availability of more water and lower additional cost to mobilize them at the farm level.
A bioeconomic analysis
International Food Policy Research Institute (IFPRI)