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The nature and processes of human adaptation to long-range climate change are poorly understood, especially in Africa (but see Chemane et al., 1997; Vogel, 1998). Often, human responses are assumed, or assumed to be rational with foresight and equity. Chapter 18, Smith and Lenhart (1996), and Smithers and Smit (1997) provide overviews; national assessments provide more detail.
A promising approach for much of Africa is to cope with current climate variability through the use of seasonal climate forecasting (e.g., Mason et al., 1996; Mattes and Mason, 1998; Washington et al., 1999; Dilley, 2000). If farmers can adapt to current year-to-year variability through the use of advance information on the future season's climate and institutional systems are in place to respond to short-term changes (such as early warning systems), communities will be in a position to adapt to longer term climate changes. For example, a seasonal maize water-stress forecast for the primary maize-growing regions of South Africa and Zimbabwe anticipates water stress 6 months prior to harvest, with hindcast correlation over 16 seasons of 0.92 for South Africa and 0.62 for Zimbabwe, based on correlations between water stress and historical global SST and sea-level pressure records (Martin et al., 2000). Similar forecasts are possible in other regions and for other crops; however, seasonal forecasting by itself will not improve food security (e.g., Stack, 1998).
Better soil and water conservation practices, more tolerant crop varieties, improved pest and weed control, and more use of irrigation also are needed to adapt to changes in the weather. Omenda et al. (1998) recommend that in areas predicted to have a decline in precipitation, research into the development of maize varieties that are higher yielding, drought-resistant, early maturing, and disease- and pest-tolerant is desirable. They further suggest that methods of improving maize culture be studied, including use of inorganic fertilizers and manure and changes in planting dates. Better adaptation to climate change also will result from the use of improved technologies in agriculture—for example, in irrigation and crop husbandry. It has been suggested (Pinstrum-Anderson and Pandya-Lorch, 1999), for example, that by failing to capitalize on new opportunities that biotechnology offers, SSA may further add to its food insecurity and poverty problems.
Increased meat production can be achieved without massive expansion of area grazed or size of the herds, by application of modern herd and animal diet management. In many situations, this would require a cultural shift from regarding livestock principally as an asset and symbol to regarding them as a production system. Cow-calf systems with supplemental feeding can achieve offtakes of 40% yr-1 (compared to the 10-20% typical of most current herd management in Africa), permitting lower livestock numbers per hectare (Preston and Leng, 1987). This would achieve a reduction in CO2 and CH4 emissions. A limited amount of increased heat tolerance can be introduced through breeding programs.
The Senegal River basin (SRB) provides an illustration of sensitivity to climatic variations and opportunities for adaptation. The SRB is undergoing fundamental environmental, hydrologic, and socioeconomic transitions (Venema et al., 1997). Senegal, Mauritania, and Mali—through the river basin development authority, the Organisation pour la Mise en Valeur du Fleuve Senegal (OMVS)—are promoting irrigated rice production for domestic consumption in the river basin to ease the severe foreign exchange shortfalls facing these riparian nations. With the recent completion of Manantali and Diama dams, year-round irrigated agriculture is now possible in the SRB. The full agricultural development potential of the SRB is constrained, however, by the basin's limited water resources, which are sensitive to climatic variations. An alternative approach to the SRB's scarce water resources is an agricultural development policy that is based on village-scale irrigation projects and intensive, irrigated agroforestry projects (Venema et al., 1997). Village-scale irrigation is dedicated to low-water-consumption cereal grain crops and is managed by traditional sociopolitical structures. The proposed agroforestry production system has the dual objectives of using irrigation to reestablish a protective biomass cover in the desertifying river valley and reversing drought-induced migration from rural to urban areas. A comparative river system simulation was carried out to analyze the effects of the rice production development policy and the natural resources management policy on the SRB's full agricultural development potential. The simulation study compared three alternative hydrologic scenarios, using the pre-drought era, the 1970s-level drought, and the 1980s-level drought. Dynamic programming applied to water allocation in the Manantali reservoir showed that lower overall water demands for the natural resource policy scenarios had higher agricultural development potential than the proposed policy based on rice production.
A significant drawback in combating effects of climate variability is the failure of African governments to devolve power to people who are affected and to link environmental degradation to economic policy (Darkoh, 1998). Consequently, many programs lack local support or are undermined by conflicting trade and agricultural policies pursued by governments. It is contended that, for sustainable development strategies to work, policies should put the welfare of people at the center of the development agenda and give them the rights and power to determine their future. Policies should empower the people to develop adaptive strategies toward sustainable livelihoods. Moreover, threats posed to the environment and development by protection and overconsumption in the north and structural adjustment programs (SAPs) call for the removal of distortions created by the import barriers of developed countries, curbing of overconsumption, and a fundamental revision in the structure of SAPs to help alleviate poverty and protect the environment in these African countries. It is in the interest of the global community that the environment in Africa is protected.
Operational early warning systems in Africa—including the SADC Regional Early Warning Unit, the U.S. Agency for International Development (USAID) Famine Early Warning System Network, and the World Food Program (WFP) Vulnerability Assessment and Mapping unit—assess the vulnerability of rural households in many parts of Africa to food insecurity each year. Vulnerability assessments generally develop a picture of which geographic areas and which social groups will be unlikely to meet their subsistence needs before the next agricultural season, based on a convergence of available environmental and socioeconomic information (USAID, 1999). The USAID Sahel vulnerability assessment for 1999-2000 estimated that 3.8 million people were moderately food insecure in a high-rainfall year (USAID, 2000). This could signify chronic vulnerability resulting from structural weaknesses caused by desertification, climate change, and other long-term environmental and socioeconomic phenomena.
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