Climate change in Africa pertains to aspects of climate change within the continent of Africa. Climate change is already a reality in Africa. According to the Intergovernmental Panel on Climate Change, Africa is among the most vulnerable continents to climate change. The vulnerability of Africa to climate change is driven by a range of factors that includes weak adaptive capacity, high dependence on ecosystem goods for livelihoods, and crude agricultural production system. The risks of climate change on agricultural production, food security, water resources and ecosystem services would likely have severe consequence on lives and sustainable development prospects in Africa. Managing this risk requires integration of mitigation and adaptation strategies in the management of ecosystem goods and services, and the agriculture production systems in Africa.
Generally, observed surface temperatures have increased over Africa since the late 19th century to the early 21st century by about 0.5 °C while observed precipitation trends indicate spatial and temporal discrepancies in variability. The observed changes in temperature and precipitation vary regionally.
Central Africa, for the most part, is landlocked and is geographically threated by climate change. Due to its high climate variability and rainfed agriculture, Central Africa is expected to experience longer and more frequent heatwaves as well as an increase in wet extremes. The global mean temperature in this region is to increase by 1.5°C to 2°C. 
Eastern Africa is characterized by high spatio-temporal rainfall variability mainly controlled by large scale systems such as the Inter-Tropical Convergence Zone (ITCZ), variations in Sea surface temperatures (SSTs) of different ocean basins and tropical cyclones. Other systems include topographic features (highlands), inland water bodies such as Lake Victoria, and air masses. Recent trends in rainfall show a general decrease in March - May (MAM) seasonal rains with a slight increase during June - September (JJAS) and October - December (OND) rains. The region has witnessed frequent and severe droughts in recent decades. Late onset and early cessation of the rainy seasons have been observed. This has been primarily attributed to the intensification of the Arabian heat low in some years particularly during the long rains. It has also been noted that the frequency and intensity of rainfall extremes has been on the rise in the recent past. On the other hand, temperature has consistently been on the rise across the region. In the future, both rainfall and temperature are projected to change over Eastern Africa. Recent studies on climate projections suggest that average temperature might increase by about 2-3 °C by the middle of the century and 2-5 °C at the end of the century. On the other hand, models show an increase in rainfall, particularly during OND season. This will depend on emission scenarios and the range of estimates of different models. It is estimated that if global temperatures rise by 2 °C instead of 1.5 °C, then temperatures over Eastern Africa are likely to increase at a faster rate than the global average.
The West African region can be divided into four climatic sub-regions namely the Guinea Coast, Soudano-Sahel, Sahel and the Sahara with different climatic conditions. These different climatic conditions including seasonal cycle of rainfall are mainly driven by the south-north movement of the Inter-Tropical Convergence Zone (ITCZ) which is characterized by the confluence between moist southwesterly monsoon winds and dry northeasterly Harmattan. Based on the interannual rainfall variability, three main climatic periods have been observed: the wet period from 1951 to 1970 followed by a dry period from 1971 to 1990 and the 1991 to 2015 period which has seen a partial rainfall recovery. During the dry period, the West African region experienced severe drought events, with devastating effects particularly in the Sahel region. The recent decades, have also witnessed moderate increment in annual rainfall since the beginning of 1990s. However, total annual rainfall remain significantly below what was observed before the big drought. The recent 2 decades have been identified as a recovery period. However, other works like underline the continuity of the drought even though the rainfall has increased.
The region is projected to experience changes in rainfall regime. For example, enhanced warming may lead to an increase in dry spells especially across the Guinea Coast is associated with a reduction of the wet spells under both 1.5℃ and 2℃ global warming level.
Climate change will increasingly impact Africa due to many factors. These impacts are already being felt and will increase in magnitude if action is not taken to reduce global carbon emissions. The impacts include higher temperatures, drought, changing rainfall patterns and increased climate variability. These conditions have a bearing on energy production and consumption. The recent drought in many African countries, which has been linked to climate change, adversely affected both energy security and economic growth across the continent.
Agriculture is inherently sensitive to climate conditions and is one of the most vulnerable sectors to the risks and impacts of global climate change. Agriculture in most African countries is mainly small-scale and rain-fed, making it particularly vulnerable to climate variability and change. Observed and projected disruptions in precipitation patterns due to climate change are likely to shorten growing seasons and affect crop yield in many parts of Africa. Furthermore, the agriculture sector in Africa is dominated by smallholder farmers with limited access to technology and the resources to adapt.
Climate variability and change have been and continue to be, the principal source of fluctuations in global food production in countries of the developing world where production is highly rain dependent. The agriculture sector is sensitive to climate variability, especially the inter-annual variability of precipitation, temperature patterns, and extreme weather events (droughts and floods). These climatic events are predicted to increase in the future and are expected to have significant consequences to the agriculture sector. This would have a negative influence on food prices, food security, and land use decisions. Yields from rainfed agriculture in some African countries could be reduced by up to 50% by 2020. In order to prevent the future destructive impact of climate variability on food production, it is crucial to adjust or suggest possible policies to cope with increased climate variability. African countries need to build a national legal framework to manage food resources in accordance with the anticipated climate variability. However, before devising a policy to cope with the impacts of climate variability, especially to the agriculture sector, it is critical to have a clear understanding of how climate variability affects different food crops.
Water quality and availability have deteriorated in most areas of Africa particularly due to climate change. Previous research and climate projections provide enough evidence that water resources are vulnerable and have the possibility of being strongly impacted by climate change with vast ramifications on human societies. The IPCC predicts millions of people in Africa will persistently face increased water stress due to climate variability and change (IPCC 2013). Changes in precipitation patterns directly affect surface runoff and water availability. Any changes to the hydrological cycle may have significant effects on river basins of Africa. To improve understanding of past and future changes in water availability due to climate change, the IPCC (IPCC 2013) recommends using the dynamic downscaling technique. The IPCC 2013 proposed using the coordinated regional downscaling experiment (CORDEX) regional climate models which runs at a maximum of 50 km resolutions, the resolution used depends upon the size of the watershed and area coverage by the meteorological records. However, before using the climate simulations from the dynamic downscaling, it is appropriate to evaluate their performance at different spatial scale since their performance differs from one location to another and from one RCM to another.
African countries have the least efficient public health systems in the world. Infectious disease burdens such as malaria, schistosomiasis, dengue fever, meningitis, which are sensitive to climate impacts, are highest in the sub-Saharan African region. For instance, over 90 percent of annual global malaria cases are in Africa. Changes in climate will affect the spread of infectious agents as well as alter people’s disposition to these infections.
With increasing population and corresponding energy demand, energy security must be addressed because energy is crucial for sustainable development. Climate change has affected energy sectors in Africa as many countries depend on hydropower generation. Decreasing rainfall levels and droughts have resulted in lower water levels in dams with adverse impacts for hydropower generation. This has resulted in low electrical energy production, high cost of electricity and power outages or load-shedding in some African countries that depend on hydroelectric power generation. Disruptions in hydropower generation have negatively affected various sectors in countries such as Ghana, Uganda, Kenya, Tanzania.
Climate change, and resulting increased temperatures, storms, droughts, and rising sea levels, will affect the incidence and distribution of infectious disease across the globe. This is true in Africa, where malaria continues to have dramatic effects on the population. As climate change continues, the specific areas likely to experience year-round, high-risk transmission of malaria will shift from coastal West Africa to an area between the Democratic Republic of the Congo and Uganda, known as the African Highlands.
To understand the exposures that affect shifting malaria transmission rates we can look to The Epidemiologic Triad, a model that explains the relationship between exposure, transmission and causation of infectious diseases. With regards to malaria transmission rates in the African Highlands, factors and exposures resulting from drastic environmental changes like warmer climates, shifts in weather patterns, and increases in human impact such as deforestation, provide appropriate conditions for malaria transmission between carrier and host. Because of this, vectors will adapt, thrive, and multiply at a fast pace. An increase in the number of vectors that carry parasites, microbes, and pathogens that cause disease will become a health hazard for the human population. Specifically, malaria is caused by the Plasmodium falciparum and Plasmodium vivax parasites which are carried by the vector Anopheles mosquito. Even though the Plasmodium vivax parasite can survive in lower temperatures, the Plasmodium falciparum parasite will only survive and replicate in the mosquito when climate temperatures are above 20℃. Increases in humidity and rain also contribute to the replication and survival of this infectious agent. Increasing global temperatures combined with changes in land cover as a result of extreme deforestation will create ideal habitats for mosquitoes to survive in the African Highlands. If deforestation continues at its current rate, more land will be available for mosquito breeding grounds, and the population of mosquitos will rapidly increase. The increase in mosquitoes will thus increase the opportunity for both Plasmodium falciparum and Plasmodium vivax parasites to proliferate.
Exposure to malaria will become a greater risk to humans as the number of female Anopheles mosquitos infected with either the Plasmodium falciparum or Plasmodium vivax parasite increases. The mosquito will transmit the parasite to the human host through a bite, resulting in infection. Then, when an uninfected mosquito bites the now infected human host, the parasite will be transmitted to the mosquitoes which will then become an exposure to other uninfected human hosts. Individuals who are constantly exposed to the Malaria parasite due to multiple bites by mosquitoes that carry the parasite are at greater risk of dying. Infected humans can also transmit the disease to uninfected or healthy humans via contaminated blood.
The health effects caused by shifts in malaria transmission rates in the African Highlands have the potential to be severe. Research has shown that the effects of climate change on health will impact most populations over the next few decades. However, Africa, and specifically the African Highlands, are susceptible to being particularly negatively affected. In 2010, 91% of the global burden due to malaria deaths occurred in Africa. Several spatiotemporal models have been studied to assess the potential effect of projected climate scenarios on malaria transmission in Africa. A study conducted by Caminade et al. concluded that the most significant climate change effects are confined to specific regions, including the African Highlands. These results are consistent with previous studies.
Ultimately, studies show an overall increase in climate suitability for malaria transmission resulting in an increase in the population at risk of contracting the disease. Of significant importance is the increase of epidemic potential at higher altitudes (like the African Highlands). Rising temperatures in these areas have the potential to change normally non-malarial areas to areas with seasonal epidemics. Consequently, new populations will be exposed to the disease resulting in healthy years lost. In addition, the disease burden may be more detrimental to areas that lack the ability and resources to effectively respond to such challenges and stresses.
Scientific limitations when examining shifting malaria transmission rates in the African Highlands are similar to those related to broader understandings of climate change and malaria. While modeling with temperature changes shows that there is a relationship between an increase in temperature and an increase in malaria transmission, limitations still exist. Future population shifts that affect population density, as well as changes in behavior of mosquitos, can affect transmission rates and are limiting factors in determining future risk of malaria outbreaks, which also affect planning for correct outbreak response preparation.
The challenges of controlling and possibly eradicating malaria in the African Highlands are many and varied. Many of the strategies used to control malaria have not changed, are few in number and have rarely been added to in the last 20 years.
The most common forms of control are educating the public and vector control. The huge geographic area of the vectors Anopheles is possibly the largest challenge faced in the control of malaria. With such a large area to cover it is hard to use insecticides at a continuous and effective level. This form of control is expensive, and the areas affected are not able to sustain control. Without sustained control, a rapid resurgence in parasite transmission is seen. Another challenge with insecticides is that the vector is now becoming insecticide resistant. Due to the fact that mosquitoes have several generations per year, resistance is seen very quickly.
Education has its limitations as well, as the population most affected by malaria is children, and the educational message is to stay inside during peak mosquito activity. The low socioeconomic status of the people who inhabit the African Highlands is also a challenge. Local health facilities have limited resources, and poor living conditions and malnourishment exacerbate malaria symptoms and increase the likelihood of death due to malaria. As climate change shifts geographic areas of transmission to the African Highlands, the challenge will be to find and control the vector in areas that have not seen it before, and to not waste resources on areas where the temperature is no longer conducive to parasite growth.
The solutions that can help malaria control and possibly lead to eradication are far fewer in number than the challenges, but if they are effective they can truly change the areas currently affected. There are number of groups working on a vaccine, some are looking to control the transmission of the parasite to the host, or control transmission from human back to the vector. These vaccines are not very effective currently, and lose their effectiveness over time, so are not ideal. But, the development is still progressing in the hopes of finding a better, more effective long lasting vaccine. An alternative to vaccines is vectored immunoprophylaxis (VIP) that is a form a gene therapy. This therapy will change cells in the host that will secrete antigens from various stages of the parasite in the hopes of triggering an anamnestic immune response in the recipient and prevent disease and parasite transmission.
The policy implications of climate change and malaria rates in the African Highlands are also vast, and ultimately fall into two categories:
Addressing both of these areas is of great importance, as those in the poorest countries, including countries that make up the African Highlands, face the greatest burden. Additionally, when countries are forced to contend with a disease like malaria, their prospects for economic growth are slowed. This contributes to continued and worsening global inequality.
When addressing policy that will reduce greenhouse gas emissions, it is necessary to act on a global scale, even when related effects are narrowed to a smaller area. The 2015 Lancet Commission on Health and Climate Change made nine recommendations for governments to address. These include:
When one focuses on mitigation, specifically as it relates to malaria in the African Highlands, research is still an important component. This research needs to take many forms, including attribution studies, to help clarify the degree to which malaria rates are attributed to climate change; scenario modeling, which can help further our understanding of future climate change consequences on malaria rates; and examinations of intervention programs and techniques, to help our understanding of what appropriate responses are. Surveillance and monitoring of malaria in populations in the African Highlands will also be important, to better understand disease.
Beyond these research priorities, it is also important that we enact policies that will significantly increase investments in public health in the African Highlands. This achieves two goals, the first being better outcomes related to malaria in the affected area, and the second being an overall better health environment for populations. It is also important to focus on “one-health approaches." This means collaborating on an interdisciplinary level, across various geographic areas, to come up with workable solutions.
These policies can be seen in action in the World Health Organization's “Adaptation to Climate Change in Africa Plan of Action for the Health Sector 2012-2016." This report “is intended to provide a comprehensive and evidence-based coordinated response of the health sector to climate change adaptation needs of African countries in order to support the commitments and priorities of African governments." The action plan includes goals like scaling up public health activities, coordinating efforts on an international scale, strengthening partnerships and collaborative efforts, and promoting research on both the effects of climate change as well as effective measures taken in local communities to mitigate climate change consequences.
Fifteen percent of Sahel region population experienced a temperature increase of more than 1 °C from 1970 to 2010. The mean seasonal rainfall is also below the long-term average, and flooding has increased in frequency and severity. Since 1985, 54 percent of the population has been affected by five or more floods in the 17 Sahel region countries.
IPCC Sees Severe Climate Change Impacts on Africa
As climate change increasingly affects the world, Africa is at risk of facing severe impacts given its geographical position and limited adaptive capacity, exacerbated by widespread poverty and low levels of development. The Sahel region, in particular, will experience higher average temperatures over the course of the 21st century and changes in rainfall patterns, according to the Intergovernmental Panel on Climate Change (IPCC). These trends will affect the frequency and severity of floods, droughts, desertification, sand and dust storms, desert locust plagues and water shortages.