Climate Change in Africa
Africa, the second largest continent, has a wide range of climates that range from the hyper- arid to the very humid. The continent vulnerability to climate change largely depends on its current and future adaptive capacities, which is influenced a lot by factors such as the level of economic development, education, access to credit and adoption of technology. It is therefore difficult to have a uniform assessment of the impacts of climate on the continent. The impact of climate change in hence normally assessed at sub-regional and national levels where relevant data exist.
Africa has a highly variable and unpredictable climate that is not fully understood by climatologists. However, observational records show that Africa has been warming through the 20th century at the rate of about 0.05°C per decade with slightly larger warming in the June-November seasons than in December-May. The most significant climatic change that has occurred in Africa has been a long-term reduction in rainfall in the semi-arid regions of West Africa. For example, in the Sahel there has been on average a 25% decrease in rainfall over the past 30 years – characterized by a decrease in the number of rainfall events. This reduction has been much more moderate in regions other than the Sahel.
3. Existing Non-Climate Vulnerabilities
Africa’s vulnerability to climate change is not only due to climate change itself, but a combination of social, economic and other environmental factors. It is the interaction of all these multiple stressors with climate change that makes the region the most vulnerable. These vulnerabilities include the region’s high population growth rate, pervasive and growing poverty, high prevalence of malnutrition, low literacy rates, a high burden of disease, prevalence of environmental disasters such as floods and droughts amongst the others. Furthermore, the region is also characterized by poor governance, corruption, conflicts and weak institutions.
4. Vulnerability to Past and Current Climate changes
4.1 Climate variability:
Africa’s climate is highly variable. This variability is manifested through climate extremes such as droughts and floods, both of which are products of extreme rainfall events. Droughts and floods have increased in frequency and severity over the past 30 years. Droughts have largely occurred in the Sahel and in some parts of Southern Africa. During the Sahelian drought of the early 1970s, about 300 000 people and millions of animals died.
Recurrent droughts are becoming very common in several parts of the continent, with its impacts on the existing population increasing exponentially. Floods have also caused a lot of havoc particularly in southern and eastern Africa around the coasts of the Indian Ocean. Mozambique for instance, is one of the poorest countries in the continent that is highly vulnerable to disasters caused by climatic irregularities. In recent years the country has witnessed frequent floods and cyclones, with severe negative impact on the country’s economic and social development. In 2000 floods in Mozambique resulted in 2 million people being displaced, about 350,000 jobs lost and the livelihoods of up to 1.5 million people affected.
Over 300 Million people in Africa do not have reasonable access to safe drinking water and adequate sanitation. The water access is worse in rural areas where about 47% are covered in comparison to about 85% in the urban areas. In terms of run-off and its effects on river flow regimes, there are sub-regional variations with the largest increases being found in the eastern areas of South Africa and Tanzania, south west Angola, northern Zambia and eastern Tanzania. The largest decreases of runoff are found in the wetter northern regions of Southern Africa. Such declines in river flows have negative consequences on livelihoods, agriculture, fisheries and energy production.
Africa has a heavy disease burden largely caused by vector-borne diseases that are influenced by climatic elements. About 90% of all malaria cases occur in Africa. More than 110 million people in Africa live in regions prone to malaria epidemics, with the most vulnerable populations located in the fringes of the current infected areas. Malaria is responsible for about 91% of all mortalities in Africa. With changes in climate, there is already significant increase in the occurrence of the disease, particularly in areas that did not have previous incidences of malaria, such as the east African highlands. Coupled with the high economic costs of treating the disease, it is expected that an increase in malaria incidence and prevalence could lead to increase in poverty. Other notable climate-related diseases with similar trend in the region include meningitis and cholera.
4.4 Agriculture and Food Security:
Agriculture accounts for 20-40% of GDP in Africa. Even without climate change, there are serious concerns about agriculture because of water supply variability, soil degradation, and recurring drought events. A number of countries face semi-arid conditions that make agriculture challenging. African agriculture has the slowest record of productivity increase in the world, and the lowest share of irrigated cropland. A significant fraction of cropland resides in the driest regions, with 39% of the irrigation considered unsustainable. Sub-Saharan Africa is notably, the world’s only major region where food output per capita has been stagnant since 1980. One key factor of this stagnation is the declining availability of arable land per capita, which has shrunk dramatically from 0.38 to 0.25 hectare over the past twenty years, mainly because of population growth.
4.5 Environmental Conflicts and Migration:
Africa is home to several resource scarcity-induced conflicts. These conflicts range from high intensity civil wars to skirmishes between livelihood groups, as often occurs between the pastoralists and sedentary farmers. Of all the climatic elements, precipitation is known to be the major factor that influences onset of conflicts. Several instances of climate related conflicts in sub-Saharan Africa have been noted. With the projected decline of precipitation and hence biodiversity, most regions in the continent might witness an increase in these scarcity-induced conflicts.
5. Projected Future Impacts
Climate change models and scenarios:
Although the exact nature of changes in temperature, precipitation, and extreme events is not known, there is consensus in literature about the following general trends: (i) the global mean surface temperature is projected to increase between 1.5 °C and 6 °C by 2100 (ii) the sea levels are projected to rise by 15 to 95 centimeters (6 to 37 inches) by 2100 resulting in flooding and salt-water intrusion. African countries will thus experience hotter and drier conditions, with the warming being greatest over the interior of semi-arid margins of the Sahara and central Southern Africa.
The projected warming is somewhat, likely to be larger than the global, annual mean warming throughout the continent and in all seasons. The drier subtropical regions (especially arid zones) are projected to warm more than the moister tropical parts. The annual rainfall is also likely to decrease in a majority of the northern Africa and northern Sahara, while winter rainfall will very likely decrease in much of Southern Africa. In East Africa, the frequency of extremely wet seasons is projected to range between 9% and 24% in JJA and DJF respectively. Projections for West Africa are somewhat similar. In South Africa, a 20% increase in the frequency of extremely dry austral winter and springs is probable.
6. Socio-Economic Scenarios:
Understanding the future impacts of climate change requires recognition of the future socio-economic situations of the existing systems. It is the interaction of climate and socio-economic conditions (usually population and GDP) that produces the final impacts. By 2030 the population growth rate of sub-Saharan Africa will be growing at 2.1 percent. It is already estimated that the population of Africa will exceed 1 billion by 2010, and eventually stabilize after 2100 at about 2.85 billion, which is three and a half times today’s population.
In sub-Saharan Africa, incomes are expected to grow very slowly and the numbers living in poverty is expected to rise from 240 million in 1990 to 345 million in 2015. By then, 40% of the region will be living in abject poverty. By 2030, all regions except sub-Saharan Africa is projected to witness decline of undernourishment to between 4% and 6%, down from between 9% and 24% witnessed today. In sub-Saharan Africa, 15% of the population or 183 million people will still be undernourished by 2030.
The impact of climate change in Africa (2010). Institute for Security Studies, South Africa. Available at: http://www.issafrica.org/uploads/Paper220.pdf
Nkomo J. C., Nyong A. O., Kulindwa K. (2006). The Impacts of Climate Change in Africa. In: The Stern Review on the Economics of Climate Change. Available at: http://www.hm-treasury.gov.uk/d/Chapter_5_The_Impacts_of_Climate_Change_in_Africa-5.pdf
Glossaries with climate change terminologies is available at: http://www.africanclimate.net/en/glossary