Confidence in the projected impacts of climate change on agricultural systems has increased substantially since the first Intergovernmental Panel on Climate Change (IPCC) reports. In Africa, much work has gone into downscaling global climate models to understand regional impacts, but there remains a dearth of local level understanding of impacts and communities’ capacity to adapt. It is well understood that Africa is vulnerable to climate change, not only because of its high exposure to climate change, but also because many African communities lack the capacity to respond or adapt to the impacts of climate change. Warming trends have already become evident across the continent, and it is likely that the continent’s 2000 mean annual temperature change will exceed +2°C by 2100. Added to this warming trend, changes in precipitation patterns are also of concern: Even if rainfall remains constant, due to increasing temperatures, existing water stress will be amplified, putting even more pressure on agricultural systems, especially in semiarid areas. In general, high temperatures and changes in rainfall patterns are likely to reduce cereal crop productivity, and new evidence is emerging that high-value perennial crops will also be negatively impacted by rising temperatures. Pressures from pests, weeds, and diseases are also expected to increase, with detrimental effects on crops and livestock. Much of African agriculture’s vulnerability to climate change lies in the fact that its agricultural systems remain largely rain-fed and underdeveloped, as the majority of Africa’s farmers are small-scale farmers with few financial resources, limited access to infrastructure, and disparate access to information. At the same time, as these systems are highly reliant on their environment, and farmers are dependent on farming for their livelihoods, their diversity, context specificity, and the existence of generations of traditional knowledge offer elements of resilience in the face of climate change. Overall, however, the combination of climatic and nonclimatic drivers and stressors will exacerbate the vulnerability of Africa’s agricultural systems to climate change, but the impacts will not be universally felt. Climate change will impact farmers and their agricultural systems in different ways, and adapting to these impacts will need to be context-specific. Current adaptation efforts on the continent are increasing across the continent, but it is expected that in the long term these will be insufficient in enabling communities to cope with the changes due to longer-term climate change. African famers are increasingly adopting a variety of conservation and agroecological practices such as agroforestry, contouring, terracing, mulching, and no-till. These practices have the twin benefits of lowering carbon emissions while adapting to climate change as well as broadening the sources of livelihoods for poor farmers, but there are constraints to their widespread adoption. These challenges vary from insecure land tenure to difficulties with knowledge-sharing. While African agriculture faces exposure to climate change as well as broader socioeconomic and political challenges, many of its diverse agricultural systems remain resilient. As the continent with the highest population growth rate, rapid urbanization trends, and rising GDP in many countries, Africa’s agricultural systems will need to become adaptive to more than just climate change as the uncertainties of the 21st century unfold.
Andrew B. Smith
African domesticated animals, with the exception of the donkey, all came from the Near East. Some 8,000 years ago cattle, sheep, and goats came south to the Sahara which was much wetter than today. Pastoralism was an off-shoot of grain agriculture in the Near East, and those herders immigrating brought with them techniques of harvesting wild grains. With increasing aridity as the Saharan environment dried up around 5000 years ago, the herders began to control and manipulate their stands resulting in millet and sorghum domestication in the Sahel Zone, south of the Sahara. Pearl millet expanded to the south and was taken up by Bantu-speaking Iron Age farmers in the savanna areas of West Africa and then spread around the tropical forest into East Africa by 3000 b.p. As the Sahara dried up and the tsetse belts retreated, sheep and cattle also moved south. They expanded into East Africa via a tsetse-free environment of the Ethiopian highlands arriving around 4000 b.p. It took around 1000 years for the pastoralists to adapt to other epizootic diseases rife in this part of the continent before they could expand throughout the grasslands of Kenya and Tanzania. Thus, East Africa was a socially complex place 3000 years ago, with indigenous hunters, herders and farmers. This put pressure on pastoral use of the environment, so using another tsetse-free corridor from Tanzania, through Zambia to the northern Kalahari, then on to the Western Cape, herders moved to southern Africa, arriving 2000b.p. They were followed to the eastern part of South Africa by Bantu-speaking agro-pastoralists 1600 years ago who were able to use the summer rainfall area for their sorghum and millet crops. Control and manipulation of African indigenous plants of the forest regions probably has a long history from use by hunter-gatherers, but information on this is constrained by archaeological evidence, which is poor in tropical environments due to poor preservation. Evidence for early palm oil domestication has been found in Ghana dated to around 2550b.p. Several African indigenous plants are still widely used, such as yams, but the plant which has spread most widely throughout the world is coffee, originally from Ethiopia. Alien plants, such as maize, potatoes and Asian rice have displaced indigenous plants over much of Africa.
Johanna Brühl, Leonard le Roux, Martine Visser, and Gunnar Köhlin
The water crisis that gripped Cape Town over the 2016–2018 period gained global attention. For a brief period of time in early 2018, it looked as if the legislative capital of South Africa would become the first major city in the world to run out of water. The case of Cape Town has broad implications for how we think about water management in a rapidly urbanizing world. Cities in the global South, especially, where often under-capacitated urban utilities need to cope with rapid demographic changes, climate change, and numerous competing demands on their tight budgets, can learn from Cape Town’s experience. The case of Cape Town draws attention to the types of decisions policymakers and water utilities face in times of crisis. It illustrates how these decisions, while being unavoidable in the short term, are often sub-optimal in the long run. The Cape Town drought highlights the importance of infrastructure diversification, better groundwater management, and communication and information transparency to build trust with the public. It also shows what governance and institutional changes need to be made to ensure long-term water security and efficient water management. The implementation of all of these policies needs to address the increased variability of water supplies due to increasingly erratic rainfall and rapidly growing urban populations in many countries. This necessitates a long-term planning horizon.
Agriculture is at the very center of the human enterprise; its trappings are in evidence all around, yet the agricultural past is an exceptionally distant place from modern America. While the majority of Americans once raised a significant portion of their own food, that ceased to be the case at the beginning of the 20th century. Only a very small portion of the American population today has a personal connection to agriculture. People still must eat, but the process by which food arrives on their plates is less evident than ever. The evolution of that process, with all of its many participants, is the stuff of agricultural history. The task of the agricultural historian is to make that past evident, and usable, for an audience that is divorced from the production of food. People need to know where their food comes from, past and present, and what has gone into the creation of the modern food system.
Caroline A. Ochieng, Cathryn Tonne, Sotiris Vardoulakis, and Jan Semenza
Household air pollution from use of solid fuels (biomass fuels and coal) is a major problem in low and middle income countries, where 90% of the population relies on these fuels as the primary source of domestic energy. Use of solid fuels has multiple impacts, on individuals and households, and on the local and global environment. For individuals, the impact on health can be considerable, as household air pollution from solid fuel use has been associated with acute lower respiratory infections, chronic obstructive pulmonary disease, lung cancer, and other illnesses. Household-level impacts include the work, time, and high opportunity costs involved in biomass fuel collection and processing. Harvesting and burning biomass fuels affects local environments by contributing to deforestation and outdoor air pollution. At a global level, inefficient burning of solid fuels contributes to climate change. Improved biomass cookstoves have for a long time been considered the most feasible immediate intervention in resource-poor settings. Their ability to reduce exposure to household air pollution to levels that meet health standards is however questionable. In addition, adoption of improved cookstoves has been low, and there is limited evidence on how the barriers to adoption and use can be overcome. However, the issue of household air pollution in low and middle income countries has gained considerable attention in recent years, with a range of international initiatives in place to address it. These initiatives could enable a transition from biomass to cleaner fuels, but such a transition also requires an enabling policy environment, especially at the national level, and new modes of financing technology delivery. More research is also needed to guide policy and interventions, especially on exposure-response relationships with various health outcomes and on how to overcome poverty and other barriers to wide-scale transition from biomass fuels to cleaner forms of energy.
Simon Holdaway and Rebecca Phillipps
Northeast Africa forms an interesting case study for investigating the relationship between changes in environment and agriculture. Major climatic changes in the early Holocene led to dramatic changes in the environment of the eastern Sahara and to the habitation of previously uninhabitable regions. Research programs in the eastern Sahara have uncovered a wealth of archaeological evidence for sustained occupation during the African Humid Period, from about 11,000 years ago. Initial studies of faunal remains seemed to indicate early shifts in economic practice toward cattle pastoralism. Although this interpretation was much debated when it was first proposed, the possibility of early pastoralism stimulated discussion concerning the relationships between people and animals in particular environmental contexts, and ultimately led to questions concerning the role of agriculture imported from elsewhere in contrast to local developments. Did agriculture, or indeed cultivation and domestication more generally (sensu Fuller & Hildebrand, 2013), develop in North Africa, or were the concepts and species imported from Southwest Asia? And if agriculture did spread from elsewhere, were just the plants and animals involved, or was the shift part of a full socioeconomic suite that included new subsistence strategies, settlement patterns, technologies, and an agricultural “culture”? And finally, was this shift, wherever and however it originated, related to changes in the environment during the early to mid-Holocene? These questions refer to the “big ideas” that archaeologists explore, but before answers can be formed it is important to consider the nature of the material evidence on which they are based. Archaeologists must consider not only what they discover but also what might be missing. Materials from the past are preserved only in certain places, and of course some materials can be preserved better than others. In addition, people left behind the material remains of their activities, but in doing so they did not intend these remains to be an accurate historical record of their actions. Archaeologists need to consider how the remains found in one place may inform us about a range of activities that occurred elsewhere for which the evidence may be less abundant or missing. This is particularly true for Northeast Africa where environmental shifts and consequent changes in resource abundance often resulted in considerable mobility. This article considers the origins of agriculture in the region covering modern-day Egypt and Sudan, paying particular attention to the nature of the evidence from which inferences about past socioeconomies may be drawn.
Carlos Eduardo Frickmann Young
Tropical forests are among the most biodiverse areas on Earth. They contribute to ecosystem functions, including regulating water flow and maintaining one of the most important carbon sinks on the planet, and provide resources for important economic activities, such as timber and nontimber products and fish and other food. Rainforests are not empty of human population and are sites of ethnically and culturally diverse cultures that are responsible for many human languages and dialects. They also provide resources for important economic activities, such as timber and nontimber products. However, tropical deforestation caused by the expansion of agricultural activities and unsustainable logging continues at very high levels. The causes of forest loss vary by region. Livestock is the main driver in the Amazon, but commercial plantations (soybeans, sugar cane, and other tradable crops) also have an impact on deforestation, in many cases associated with violent conflicts over land tenure. In Southeast Asia, logging motivated by the tropical timber trade plays an important role, although palm oil plantations are an increasing cause of deforestation. In Africa, large-scale agricultural and industrial activities are less important, and the most critical factor is the expansion of subsistence and small-scale agriculture. However, trade-oriented activities, such as cocoa and coffee plantations in West Africa and logging in Central Africa, are becoming increasingly important. Public policies have a strong influence on these changes in land use, from traditional community-based livelihood practices to for-profit livestock, cultivation, and timber extraction. Investments in infrastructure, tax and credit incentives, and institutional structures to stimulate migration and deforestation represent economic incentives that lead to deforestation. Poor governance and a lack of resources and political will to protect the traditional rights of the population and environmental resources are another cause of the continuous reduction of tropical forests. Consequently, deforestation prevents the expansion of economic activities that could be established without threats to the remnants of native forest. There are also negative social consequences for the local population, which suffers from the degradation of the natural resources on which their production is based, and is hampered by air pollution caused by forest fires. In some situations, a vicious cycle is created between poverty and deforestation, since the expansion of the agricultural frontier reduces the forest areas where traditional communities once operated, but without generating job opportunities. New approaches are required to reverse this paradigm and to lay the foundation for a sustainable economy based on the provision of ecosystem services provided by tropical forests. These include (a) better governance and public management capacity, (b) incentives for economic activities compatible with the preservation of the tropical forest, and (c) large-scale adoption of economic instruments to support biodiversity and ecosystem services. Public policies are necessary to correct market failures and incorporate the values of ecosystem services in the land use decision process. In addition to penalties for predatory actions, incentives are needed for activities that support forest preservation, so the forest is worth retaining rather than clearing. Improving governance capacity, combining advanced science and technology with traditional knowledge, and improving the management of existing activities can also help to ensure sustainable development in tropical forest regions.
In an era of calamitous climate change, entrenched malnutrition, and the chronic exclusion of hundreds of millions of people from access to affordable energy, food, and water, evaluating the policy options of African states to address these challenges matters more than ever. In the Nile Basin especially, a region notorious for its poverty, violent instability and lack of industrialisation, states have invested their scarce resources and political capital in a “hydraulic mission” in the belief that they can engineer their way out of international marginalization. Incumbents have bet on large-scale hydro-infrastructure and capital-intensive agriculture to boost food production, strengthen energy security, and deal with water scarcity, despite the woeful track-record of such a supply-side approach to development. While ruling elites in the Nile Basin have portrayed the hydraulic mission as the natural way of developing the region’s resources—supposedly validated by the historical achievements of Pharaonic civilization and its mastery over its tough environment—this is a modern fiction, spun to justify politically expedient projects and the exclusion of broad layers of the population. In the last two hundred years, the hydraulic mission has made three major political contributions that underline its strategic usefulness to centralizing elites: it has enabled the building of modern states and a growing bureaucratic apparatus around a riverain political economy; it has generated new national narratives that have allowed unpopular regimes to rebrand themselves as protectors of the nation; and it has facilitated the forging of external alliances, linking the resources and elites of Egypt, Ethiopia, and Sudan to global markets and centers of influence. Mega-dams, huge canals and irrigation for export are fundamentally about power and the powerful—and the privileging of some interests and social formations over others. The one-sided focus on increasing supply—based on the false premise that this will allow ordinary people to access more food and water—transfers control over livelihoods from one (broad) group of people to (a much narrower) other one by legitimizing top-down interventionism and dislocation. What presents itself as a strategy of water resources and agricultural development is really about (re)constructing hierarchies between people. The mirage of supply-side development continues to seduce elites at the helm of the state because it keeps them in power and others out of it.