AFRICA ENVIRONMENT OUTLOOK
Past, present and future perspectives

CLIMATE CHANGE

It is predicted that, globally, increased temperatures will lead to rising sea levels accompanied by displacement of people living in low-lying areas and loss of some island states, shifts and reductions in agricultural production, the possibility of more frequent and more severe climatic events such as droughts and flooding

Climate change is now recognized as a pressing global environmental issue. It is the result of higher mean temperatures caused by increased amounts of greenhouse gases (GHG) in the earth’s atmosphere, of which the most important is carbon dioxide released during burning of fossil fuels. Since the start of the industrial revolution (around 1750) some 270 billion tonnes of carbon have been released globally from the consumption of fossil fuels and cement production. Half of these emissions have occurred since the mid 1970s, although there was a slight decline of 0.3 per cent between 1997 and 1998 (Marland, Boden & Andres 2000).

It is predicted that, globally, increased temperatures will lead to rising sea levels accompanied by displacement of people living in low-lying areas and loss of some island states, shifts and reductions in agricultural production, the possibility of more frequent and more severe climatic events such as droughts and flooding, and possible shifts in health problems with vector-borne diseases being re-introduced or introduced into different areas.

According to the Intergovernmental Panel on Climate Change (IPCC), global average temperatures have risen by 0.6°C over the last century and the 1990–99 period was probably the warmest decade since the 1860s (IPCC 2001a). In addition, records indicate that snow and ice cover has decreased, and sea levels have risen by 10–20 cm over the last century. For example, the glaciers of Mount Kilimanjaro have shrunk by over 70 per cent over the last century (WorldWatch Institute 2000).

Africa's carbon dioxide emissions from use of fossil fuels are low in relation to other regions, in both absolute and per capita terms, as shown in Figure 2a.3. Despite the region's total emissions having risen to 223 million metric tonnes of carbon in 1998 (eight times the level in 1950), this is still less than the emissions for the United States, Mainland China, Russia, Japan, India, or Germany. Per capita emissions also increased three-fold over the same period, reaching 0.3 metric tonnes of carbon, only 5.7 per cent of the comparable value for North America.

A handful of African nations account for the bulk of the region's emissions from fossil fuels: South Africa accounts for 42 per cent with another 35.5 per cent coming from Egypt, Nigeria, and Algeria combined. This is illustrated in Figure 2a.4 (Marland and others 2000).

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Figure 2a.3: Africa’s contribution to global carbon dioxide emissions, 1972 –98

Source: CDIAC

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Figure 2a.4: Sub-regional comparison of carbon dioxide emissions 1972–98

Source: CDIAC

Although Africa contributes very little to global GHG emissions the region is highly susceptible to the impacts of climate change because of its dependency on agriculture and limited financial resources for development of mitigation strategies. The IPCC predicts that the greater variability and unpredictability of temperature and rainfall cycles in Africa resulting from climate change would alter the area of suitable land for agricultural or livestock production and increase the frequency of flooding and drought. Grain yields are expected to decline due to increased rainfall variability, especially in the Horn and Southern Africa, and desertification rates may increase (IPCC 2001b). In Central Africa and parts of Eastern Africa increased rainfall and reduced frosts are expected, resulting in an increase in the area suitable for cultivation, possibly at the expense of natural habitat.

Climate change may also have a devastating impact on human settlements and infrastructure development in Africa. Low-lying coastal areas are at particular risk from sea level rise, and many coastal urban developments are of unsuitable design or are inadequately equipped to cope with storms and flooding. In particular, the Gulf of Guinea, Senegal, Egypt, Gambia, the eastern African coast and the Western Indian Ocean Islands are at risk from sea level rise (IPCC 2001b).

Africa's natural environment could also be severely affected by climate change with impacts including changes to forest cover and grassland distribution that would result from temperature rises of 1°C or more. These in turn may result in significant changes in abundance and diversity of species. In particular, species living in arid zones will be less able to adapt, as they already exist at the very limits of their environmental tolerance (IPCC 1998). Significant extinction of plants and animals is anticipated, impacting on rural livelihoods and tourism (IPCC 2001b). For example, hartebeest, wildebeest and zebra in the Kruger National Park (South Africa), the Okavango Delta (Botswana), and Hwange National Park (Zimbabwe) could be severely threatened by the anticipated 5 per cent drop in rainfall that would affect grazing distribution (WWF 2000). Marine environments could also be affected severely—a sea temperature rise of 1–2°C could cause extensive coral bleaching in the Western Indian Ocean, affecting the economies of the coastal countries and islands.

Climate change also poses a threat to human health in Africa, through reduced nutrition and possible expansion or creation of new habitats for diseasecarrying organisms such as mosquitoes (IPCC 1998). Warmer temperatures and altered rainfall patterns could open up new areas to diseases such as malaria, yellow fever, dengue fever, and trypanosomiasis (IPCC 1998).