IPCC Fourth Assessment Report: Climate Change 2007
Climate Change 2007: Working Group II: Impacts, Adaptation and Vulnerability


Agricultural production in many African countries and regions will likely be severely compromised by climate change and climate variability. This would adversely affect food security and exacerbate malnutrition (very high confidence).

Agricultural yields and dependence on natural resources constitute a large part of local livelihoods in many, but not all, African countries. Agriculture is a major contributor to the current economy of most African countries, averaging 21% and ranging from 10% to 70% of GDP with indications that off-farm income augments the overall contribution of agriculture in some countries [9.2.2, 9.4.4]. Agricultural losses are shown to be possibly severe for several areas (e.g., the Sahel, East Africa and southern Africa) accompanied by changes in length of growing periods impacting mixed rain-fed, arid and semi-arid systems under certain climate projections. In some countries, yields from rain-fed agriculture could be reduced by up to 50% by 2020. At the local level, many people are likely to suffer additional losses to their livelihood when climate change and variability occur together with other stressors (e.g., conflict) [9.2.2, 9.6.1].

Climate change and variability are likely to result in species loss, extinctions and also constrain the ‘climate spaces’ and ranges of many plants and animals (high confidence).

Changes in a variety of ecosystems are already being detected, particularly in southern African ecosystems, at a faster rate than anticipated as a result of a variety of factors, including the influence of climate, e.g., mountain ecosystems [9.4.5, 4.4.2, 4.4.3, 4.4.8].

In unmanaged environments, multiple, interacting impacts and feedbacks are expected, triggered by changes in climate, but exacerbated by non-climatic factors (high confidence).

Impacts on Kilimanjaro, for example, show that glaciers and snow cover have been retreating as a result of a number of interacting factors (e.g., solar radiation, vegetation changes and human interactions), with a decrease in glacier surface area of approximately 80% between 1912 and 2003 (see Figure TS.10). The loss of ‘cloud forests’, e.g., through fire, since 1976 has resulted in a 25% annual reduction of water sources derived from fog (equivalent to the annual drinking water supply of 1 million people living around Mt. Kilimanjaro) [9.4.5].

Figure TS.10

Figure TS.10. Changes in the Mt. Kilimanjaro ice cap and snow cover over time. Decrease in surface area of Kilimanjaro glaciers from 1912 to 2003. [F9.2]

Lack of access to safe water, arising from multiple factors, is a key vulnerability in many parts of Africa. This situation is likely to be further exacerbated by climate change (very high confidence).

By 2020, some assessments project that between 75 and 250 million people are estimated to be exposed to increased water stress due to climate change. If coupled with increased demand, this will adversely affect livelihoods and exacerbate water-related problems. Some assessments, for example, show severe increased water stress and possible increased drought risk for parts of northern and southern Africa and increases in runoff in East Africa. Water access is, however, threatened not only by climate change [9.4.1] but also by complex river-basin management (with several of Africa’s major rivers being shared by several countries), and degradation of water resources by abstraction of water and pollution of water sources [9.4.1].

Attributing the contribution of climate change to changes in the risk of malaria remains problematic (high confidence).

Human health, already compromised by a range of factors, could also be further negatively impacted by climate change and climate variability (e.g., in southern Africa and the East African highlands). The debate on climate change attribution and malaria is ongoing and this is an area requiring further research [9.4.3, 8.2.8, 8.4.1].

Africa is one of the most vulnerable continents to climate variability and change because of multiple stresses and low adaptive capacity. The extreme poverty of many Africans, frequent natural disasters such as droughts and floods, and agriculture which is heavily dependent on rainfall, all contribute. Cases of remarkable resilience in the face of multiple stressors have, however, been shown (high confidence).

Africa possesses many examples of coping and adaptation strategies that are used to manage a range of stresses including climate extremes (e.g., droughts and floods). Under possible increases in such stresses, however, these strategies are likely to be insufficient to adapt to climate variability and change, given the problems of endemic poverty, poor institutional arrangements, poor access to data and information, and growing health burdens [9.2.1, 9.2.2., 9.2.5].