Impacts on Africa

Africa is one of the most vulnerable continents to climate change and variability, a situation that is exacerbated by existing developmental challenges such as endemic poverty; complex governance and institutional dimensions; limited access to capital, including markets, infrastructure and technology; ecosystem degradation; and complex disasters and conflicts - all of which contribute to Africa's weak adaptive capacity to climate change.61 Some projected climate impacts for Africa are summarised as follows:62

• The impacts of climate change in Africa are likely to be greatest where they co-occur with a range of other stresses (e.g., unequal access to resources, enhanced food insecurity, poor health management systems. These stresses, enhanced by climate variability and change, further enhance the vulnerabilities of many people in Africa.**

• An increase of 5% to 8% (60 to 90 million ha) of arid and semi-arid land in Africa is projected by the 2080s under a range of climate-change scenarios.**

• Declining agricultural yields are probably due to drought and land degradation, especially in marginal areas. Changes in the length of growing period have been noted under various scenarios. In the A1F1 SRES scenario, which has an emphasis on globally integrated ecconomic growth, areas of major change include the coastal systems of southern and eastern Africa. Under both the A1 and B1 scenarios, mixed rain-fed, semi-arid systems are shown to be heavily affected by changes in climate in the Sahel. Mixed rain-fed and highland perennial systems in the Great Lakes region in East Africa and in other parts of East Africa are also heavily affected. In the B1 SRES scenario, which assumes development within a framework of environmental protection, the impacts are, however, generally less, but marginal areas (e.g., the semiarid systems) become more marginal, with the impacts on coastal systems becoming moderate.**

• Current stress on water in many areas of Africa is likely to be enhanced by climate variability and change. Increases in run-off in East Africa (possibly floods) and decreases in run-off and likely increased drought risk in other areas (e.g. southern Africa) are projected by the 2050s. Current water stresses are not only linked to climate variations, and issues of water governance and water-basin management must also be considered in any future assessments of water in Africa.**

• Any changes in the primary production of large lakes are likely to have important impacts on local food supplies. For example, Lake Tanganyika currently provides 25% to 40% of animal protein intake for the population of the surrounding countries, and climate change is likely to reduce primary production and possible fish yields by roughly 30%. The interaction of human management decisions, including over-fishing, is likely to further compound fish offtakes from lakes.**

• Ecosystems in Africa are likely to experience major shifts and changes in species range and possible extinctions (e.g., fynbos and succulent Karco biomes in southern Africa).*

• Mangroves and coral reefs are projected to be further degraded, with additional consequences for fisheries and tourism.**

• Towards the end of the twenty-first century, projected sea-level rise will affect low-lying coastal areas with large populations. The cost of adaptation will exceed 5% to 10% of GDP.**

socio-economic circumstances, advances in treatment or prevention and public health infrastructure.

The potential impact of climate change on human health could be large. However, the factors involved are complex and quantitative conclusions require careful study of the direct effects of climate on humans and of the epidemiology of the diseases particularly affected. Some remarks about how the health impacts of extremes and disasters might be reduced are given in the next section.

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