Climate change in Africa
Anthropogenic climate change is already a reality in Africa, as it is elsewhere in the world. 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 less developed agricultural production systems. The risks of climate change on agricultural production, food security, water resources and ecosystem services will likely have increasingly severe consequences 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.
Over the coming decades, warming from climate change is expected across almost all the earth's surface, and global mean rainfall will increase. Regional effects on rainfall in the tropics are expected to be much more spatially variable and the sign of change at any one location is often less certain, although changes are expected. Consistent with this, observed surface temperatures have generally increased over Africa since the late 19th century to the early 21st century by about 1 °C, but locally as much as 3 °C for minimum temperature in the Sahel at the end of the dry season. Observed precipitation trends indicate spatial and temporal discrepancies as expected. The observed changes in temperature and precipitation vary regionally.
In terms of adaptation efforts, regional-level actors are making some progress. This includes the development and adoption of several regional climate change adaptation strategies e.g. SADC Policy Paper Climate Change, and the adaptation strategy for the water sector. In addition, there has been other efforts to enhance climate change adaptation, such as the tripatite Programme on Climate Change Adaptation and Mitigation in Eastern and Southern Africa.
As a supranational organisation of 55 member states, the African Union has put forward 47 goals and corresponding actions in a 2014 draft report to combat and mitigate climate change on the continent. The Secretary General of the United Nations has also declared a need for close cooperation with the African Union in order to tackle climate change, in accordance with the UN's sustainable development goals.
Impacts
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 and food security
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. 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.
In the year 2020, sever invasion of Locusts harmed the agriculture in eastern Africa. The invasion is at least partly due to climate change - the warmer temperature and heavier rainfall caused an abnormal increase in the number of locusts
Water resources
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. 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 recommends using the dynamic downscaling technique. The IPCC 2013 proposed using the coordinated regional downscaling experiment 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 scales since their performance differs from one location to another and from one RCM to another.Health
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.Energy
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 on 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.Regional differences
Central Africa
Central Africa, for the most part, is landlocked and is geographically threatened 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.Central Africa Adaption Measures
Angola - "The objective of the National Adaptation Programs of Action are to identify and communicate the urgent and immediate needs of the country regarding climate change adaptation, to increase Angola‘s resilience to climate variabilities and to climate change to ensure achievement of Poverty reduction programs, sustainable development objectives and the Millennium Development Goals pursued by the Government."Effects
The carbon dioxide-absorbing capacity of forests in the Congo Basin have decreased. This decrease has occurred due to increasing heat and drought causing decreased tree growth. This suggests that even unlogged forests are being affected by climate change. A Nature study indicates that by 2030, the African jungle will absorb 14 percent less carbon dioxide than it did from around 2005-2010, and will absorb none at all by 2035.Eastern Africa
Situated almost entirely in the tropics, rainfall in Eastern Africa is dominated by the seasonal migration of the tropical-rain band. Eastern Africa is characterized by high spatio-temporal rainfall variability as it spans over 30 degrees of latitude. It has influences from both the Indian and Atlantic Oceans, and has major orographic features as well as inland water bodies such as Lake Victoria. Therefore the rainfall seasonality varies from a single wet season per year in July–August in parts of the northwest to a single wet season per year in December - February in the south, with many areas close to the equator having two rainy seasons per year, approximately in March–May and October to December. Fine-scale variability in rainfall seasonality is often linked to orography and lakes. Inter-annual variability can be large and known controls include variations in Sea surface temperatures of different ocean basins, large-scale atmospheric modes of variability such as the Madden-Julian Osciliation and tropical cyclones.Eastern Africa has witnessed frequent and severe droughts in recent decades, as well as devastating floods. Trends in rainfall since the 1980s show a general decrease in March - May seasonal rains with a slight increase during June - September and October - December rains, although there appears to have been a recent recovery in the MAM rains. 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. This will depend on emission scenarios as well as on how the real climate responds compared with the range of possible outcomes shown by models. Climate model projections tend to show an increase in rainfall, particularly during OND season, which is also projected to occur later. This delay in the short rain season, has been linked to the deepening of the Saharan Heat Low under climate change. It should be noted, however that some models predict decreasing rainfall, and for some regions and seasons the very largest rainfall increases predicted have been shown to involve implausible mechanisms due to systematic model errors. In addition, changes of aerosols provide a forcing of rainfall change that is not captured in many assessments of climate projections.
The contrast of the drying trend of MAM rainfall in equatorial Eastern Africa, with most models predicting a wetting in the future has been labelled the “East African climate change paradox," although there has been some recent recovery in the rainfall. Studies have shown that the drying trend is unlikely to be purely natural, but may be driven by factors such as aerosols rather than greenhouse gases, further research is needed. The drying has been shown to be have been caused by a shorter rainy season, and linked to deepening of the Arabian Heat Low.
Consistent with the uncertainty in rainfall projections, changes in rainy seasons onset are uncertain in equatorial Eastern Africa, although many models predict a later and wetter short rains. The Indian Ocean Dipole is known to provide a strong control on inter-annual variability in the short rains, and studies show that extreme IODs may increase under climate change.
Globally, climate change is expected to lead to intensification of rainfall, as extreme rainfall increases at a faster rate with warming than total rainfall does. Recent work shows that across Africa global models are expected to under-estimate the rate of change of this rainfall intensification, and changes in rainfall extremes may be much more widespread than those predicted by global models.
Southern parts of Eastern Africa receive most of their rainfall in a single rainy season during the southern hemisphere’s winter: over Tanzania seasonal rainfall is projected to increase under future climate change, although there is uncertainty. Further south, over Mozambique, a shorter season due to a later onset is projected under future climate change, again with some uncertainty.
East Africa Adaption Measures
Comoros - "NAPA is the operational extension of the Poverty Reduction Strategy Paper, as it includes among its adaptation priorities, agriculture, fishing, water, housing, health, but also tourism, in an indirect way, through the reconstitution of basin slopes and the fight against soils erosion, and therefore the protection of reefs by limiting the silting up by terrigenous contributions."Kenya gazetted the which establishes an authority to oversee development, management, implementation and regulation of mechanisms to enhance climate change resilience and low carbon development for sustainable development, by the National and County Governments, the private sector, civil society, and other actors. Kenya has also developed the National Climate Change Action Plan which aims to further the country's development goals by providing mechanisms and measures to achieve low carbon climate-resilient development in a manner that prioritizes adaptation.
Madagascar - the priority sectors for adaptation are: agriculture and livestock, forestry, public health, water resources and coastal zones.
Malawi - The NAPA identifies the following as high priority activities for adaptation: "Improving community resilience to climate change through the development of sustainable rural livelihoods, Restoring forests in the Upper and Lower Shire Valleys catchments to reduce siltation and associated water flow problems, Improving agricultural production under erratic rains and changing climatic conditions, Improving Malawi’s preparedness to cope with droughts and floods, and Improving climate monitoring to enhance Malawi’s early warning capability and decision making and sustainable utilization of Lake Malawi and lakeshore areas resources".
Mauritius - adaptation should address the following priority areas: coastal resources, agriculture, water resources, fisheries, health and well-being, land use change and forestry and biodiversity.
Mozambique - "The proposed adaptation initiatives target various areas of economic and social development, and outline projects related to the reduction of impacts to natural disasters, the creation of adaptation measures to climate change, fight against soil erosion in areas of high desertification and coastal zones, reforestation and the management of water resources."
Rwanda has developed the National Adaptation Programme of Action which contains information to guide national policy-makers and planners on priority vulnerabilities and adaptations in important economic sectors. The country has also developed sector based policies on adaptation to climate change such as the Vision 2020, the National Environmental Policy and the Agricultural Policy among others.
Tanzania Tanzania has outlined priority adaptation measures in their NAPA, and various national sector strategies and research outputs. The NAPA has been successful at encouraging climate change mainstreaming into sector policies in Tanzania; however, the cross-sectoral collaboration crucial to implementing adaptation strategies remains limited due to institutional challenges such as power imbalances, budget constraints and an ingrained sectoral approach. Most of the projects in Tanzania concern agriculture and water resource management ; however, energy and tourism also play an important role.
Zambia - "The NAPA identifies 39 urgent adaptation needs and 10 priority areas within the sectors of agriculture and food security, energy and water, human health, natural resources and wildlife"
Zimbabwe''' - "The other strategic interventions by the NAP process will be: Strengthening the role of private sector in adaptation planning, Enhancing of the capacity of Government to develop bankable projects through trainings, Improving management of background climate information to inform climate change planning, Crafting a proactive resource-mobilization strategy for identifying and applying for international climate finance as requests for funds are primarily reactive at present, focusing on emergency relief rather than climate change risk reduction, preparedness and adaptation, Developing a coordinated monitoring and evaluation policy for programs and projects, as many institutions within the government do not currently have a systematic approach to monitoring and evaluation. "
[North Africa]
[Southern Africa]
Southern Africa Adaption Measures
Lesotho - "The key objectives of the NAPA process entail: identification of communities and livelihoods most vulnerable to climate change, generating a list of activities that would form a core of the national adaptation program of action, and to communicate the country’s immediate and urgent needs and priorities for building capacity for adaptation to climate change"Namibia - the critical themes for adaptation are "Food security and sustainable biological resource base, Sustainable water resources base,Human health and well being and Infrastructure development"
South Africa is in the progress of finalizing its national climate change adaptation strategy. "The National Adaptation strategy acts as a common reference point for climate change adaptation efforts in South Africa, and it provides a platform upon which national climate change adaptation objectives for the country can be articulated so as to provide overarching guidance to all sectors of the economy"
West Africa and the Sahel
The West African region can be divided into four climatic sub-regions namely the Guinea Coast, Soudano-Sahel, Sahel and the Sahara, each with different climatic conditions. The seasonal cycle of rainfall is mainly driven by the south-north movement of the Inter-Tropical Convergence Zone which is characterised by the confluence between moist southwesterly monsoon winds and the dry northeasterly Harmattan.Based on the inter-annual rainfall variability, three main climatic periods have been observed over the Sahel: the wet period from 1950 to the early 1960s followed by a dry period from 1972 to 1990 and then the period from 1991 onwards which has seen a partial rainfall recovery. During the dry period, the Sahel experienced a number of particularly severe drought events, with devastating effects. The recent decades, have also witnessed a moderate increment in annual rainfall since the beginning of 1990s. However, total annual rainfall remains significantly below that observed during the 1950s.
Some have identified the recent 2 decades as a recovery period. Others refer to this as a period of ‘hydrological intensification’ with much of the annual rainfall increase coming from more severe rain events and sometimes flooding rather than more frequent rainfall, or similarly other works underline the continuity of the drought even though the rainfall has increased. Since 1985, 54 percent of the population has been affected by five or more floods in the 17 Sahel region countries. In 2012, severe drought conditions in the Sahel were reported. Governments in the region responded quickly, launching strategies to address the issue.
The region is projected to experience changes in rainfall regime, with climate models suggesting that decreases in wet season rainfall are more likely in the western Sahel, and increases more likely in the central to east Sahel, although opposite trends cannot yet be ruled out. These trends will affect the frequency and severity of floods, droughts, desertification, sand and dust storms, desert locust plagues and water shortages.
However, irrespective of the changes in seasonal mean rain, the most intense storms are expected to become more intense, amplifying flood frequency. Enhanced carbon emissions and global warming may also lead to an increase in dry spells especially across the Guinea Coast associated with a reduction of the wet spells under both 1.5℃ and 2℃ global warming level.
Fifteen percent of Sahel region population has also experienced a temperature increase of more than 1 °C from 1970 to 2010. 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.
African Highlands
Shifts in Malaria Transmission Due to Climate Change
Climate change, and resulting in 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 the 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.''Exposures''
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.
''Health Effects''
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. 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''
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 the behavior of mosquitos, can affect transmission rates and are limiting factors in determining the future risk of malaria outbreaks, which also affect planning for correct outbreak response preparation.''Challenges and Solutions''
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 are 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 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.
''Policy Implications''
The policy implications of climate change and malaria rates in the African Highlands are also vast, and ultimately fall into two categories:- Enacting policy that will reduce greenhouse gas emissions, thus slowing down climate change, and
- Mitigating problems that have already arisen, and will inevitably continue to develop, due to climate change.
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:
- Make an investment in climate change research.
- Increase financing for global health systems.
- Eliminate coal as an energy source.
- Support cities that encourage healthy activities for individuals and the planet.
- Clarify carbon pricing.
- Increase access to renewable energy in low to middle-income countries.
- Quantify avoided burdens when these measures are taken.
- Collaborate with global governments and health organizations.
- Create an agreement that will help counties making changes to become low-carbon economies.
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.