There is limited research providing quantitative estimates of adaptation costs across Africa. Adaptation costs in Africa have been estimated at USD 7–15 billion per year by 2020 (Schaeffer et al., 2013), corresponding to USD 5–11 per capita per year. The African Development Bank estimates costs of near-term adaptation needs identified in the Intended NDCs (INDCs) of African countries as USD 7.4 billion per year from 2020, recognising INDCs describe only a limited subset of adaptation needs (AfDB, 2019). Many African countries, particularly Least Developed Countries (LDCs), express a stronger demand for adaptation finance—a study of financial demands in INDCs for 16 African countries suggests a ratio around 2:1 for adaptation to mitigation finance with demand for Eritrea and Uganda approximately 80% for adaptation (Zhang and Pan, 2016).

Adaptation costs in Africa are expected to rise rapidly as global warming increases (high confidence). A meta-analysis of adaptation costs identified in 44 NDCs and National Adaptation Plans (NAPs) from developing countries estimated a median adaptation cost around USD 17 per capita per year for 2020–2030 (Chapagain et al., 2020). Adaptation cost estimates for Africa increase from USD 20–50 billion per year for Representative Concentration Pathway (RCP) 2.6 in 2050 (around 1.5°C of warming), to USD 18–60 billion per year for just over 2°C, to USD 100–437 billion per year for 4°C of global warming above pre-industrial levels (Schaeffer et al., 2013; UNEP, 2015; Chapagain et al., 2020). Focusing on individual sectors, the average country-level cost is projected to be USD 0.8 billion per year for adapting to temperature-related mortality under 4°C global warming (Carleton et al., 2018), with cumulative energy costs for cooling demand projected to reach USD 51 billion by 2°C and USD 486 billion by 4°C global warming (Parkes et al., 2019). Transport infrastructure repair costs are also projected to be substantial (Section 9.8.2) More precise estimates are limited by methodological difficulties and data gaps for costing adaptation, uncertainties about future levels of global warming and associated climate hazards, and ethical choices such as the desired level of protection achieved (Fankhauser, 2010; Hallegatte et al., 2018; UNFCCC, 2018) (Cross-Chapter Box FINANCE in Chapter 17). As such, existing estimates are expected to substantially underestimate eventual costs with adaptation costs possibly 2–3 times higher than current global estimates by 2030, and 4–5 times higher by 2050 (UNEP, 2016a).

Although analysts face challenges related to the nature of climate change impacts (Sussman et al., 2014) and data limitations (Li et al., 2014) when estimating all costs and benefits for adaptation measures in specific contexts, adaptation generally is cost-effective (high confidence). The Global Commission on Adaptation estimated the benefits and costs of five illustrative investments and found benefit–cost ratios ranging from 2:1 to 10:1. However, it also noted that ‘actual returns depend on many factors, such as economic growth and demand, policy context, institutional capacities and condition of assets’ (The Global Commission on Adaptation, 2019). A review of ex-ante cost–benefit analyses for 19 adaptation-focused projects in Africa financed by the Green Climate Fund (GCF) shows benefit–cost ratios in a similar range. Using a 10% discount rate, as used by many of GCF’s accredited entities, the benefit–cost ratio for individual projects ranges from 0.9:1 to 7.3:1, the median benefit–cost ratio is 1.8:1 and total ratio across all 19 projects is 2.6:1. When using lower discount rates, as some entities do for climate projects, the benefit–cost ratio is even higher, reflecting the front-loaded costs and back-loaded benefits of many adaptation investments. Using a 5% discount rate, the overall benefit–cost ratio of the GCF projects is 3.5:1, with a range from 1:1 to 11.5:1 and a median ratio of 2.4:1 (Breitbarth, 2020). In addition, many proposals have activities for which further benefits were not estimated due to the difficulty of attributing benefits directly to the intervention. The benefits of adaptation measures for infrastructure and others with clear market impacts are often easier to estimate than for policy interventions and where markets may not exist, such as ecosystem services (Li et al., 2014).

The amounts of finance being mobilised internationally to support adaptation in African countries are billions of US dollars less than adaptation cost estimates, and finance has targeted mitigation more than adaptation (high confidence). The Organisation for Economic Co-operation and Development (OECD (2020) estimates an average of USD 17.3 billion per year in public finance targeting mitigation and adaptation from developed countries to Africa in 2016–2018, with adaptation expected to be a small share of this amount. Of the global total, only 21% in 2018 targeted adaptation (there is no breakdown provided for Africa). Analysis of OECD data that is reported by the funders, covering bilateral and multilateral funding sources, estimated international public finance (grants and concessional lending) committed to Africa for climate change for 2014–2018 at USD 49.9 billion: 61% (30.6 billion) for mitigation, 33% (16.5 billion) for adaptation and 5% (2.7 billion) for both objectives simultaneously (Figure 9.8a; Savvidou et al., 2021). This equates to an average of USD 3.8 billion per year targeting adaptation (Savvidou et al., 2021). In per capita terms, only two countries (Djibouti and Gabon) were supported with more than USD 15 per person per year, most were supported with less than USD 5 per person per year (Savvidou et al., 2021).

The multilateral development banks (MDBs) report 43% of their climate-related commitments to sub-Saharan Africa in 2018 targeted adaptation (EBRD et al., 2021). Sources other than international public finance are more difficult to track and there is limited data on Africa (Cross-Chapter Box FINANCE in Chapter 17). Considering a wider range of finance types (including private flows and domestic mobilisation), an estimated annual average of roughly USD 19 billion in climate finance for 2017–2018 went to sub-Saharan Africa, of which only 5% was for adaptation (CPI, 2019; Adhikari and Safaee Chalkasra, 2021). The mobilisation of private finance by developed country governments, through bilateral and multilateral financial support, is lower in Africa relative to other world regions. Globally, in 2016–2018, Africa made up only 17% of mobilised private finance relevant for climate change (OECD, 2020).

Strong differences exist among African sub-regions. Finance commitments targeting adaptation increased from 2014–2018 for east and west Africa but decreased in central Africa (Savvidou et al., 2021) (Figure 9.8b). Climate-related finance was >50% for adaptation in 19 countries, while 26 received >50% for mitigation (Savvidou et al., 2021).

African countries expect grants to play a crucial role in supporting adaptation efforts because loans add to already high debt levels that exacerbate fiscal challenges, especially in light of high sovereign debt levels from the COVID-19 pandemic (Bulow et al., 2020; Estevão, 2020). From 2014–2018, more finance commitments targeting adaptation in Africa were debt instruments (57%) than grants (42%) (Savvidou et al., 2021).

For Africa combined, the sectors targeted with most support for adaptation are agriculture and water supply and sanitation, which account for half of total adaptation finance from 2014–2018 (Figure 9.9a). The sectoral distribution has changed little over these years, suggesting adaptation planners and funders are maintaining a relatively narrow view of where support is needed and how to build climate resilience (Savvidou et al., 2021).

However, to understand actual expenditure on adaptation, it is necessary to look at disbursements (that is, the amounts paid out compared to committed amounts). Low ratios of disbursements to commitments suggest difficulties in project implementation. Disbursement ratios for climate-related finance from all funders other than MDBs (for which data is not published) in Africa are very low (Figure 9.9b; Savvidou et al., 2021). Only 46% of 2014–2018 commitments targeting adaptation were dispersed (Savvidou et al., 2021). Regions faring worst are north Africa (15%), central Africa (33%) and west Africa (33%) (Figure 9.9c). These disbursement ratios for adaptation and mitigation finance in Africa are lower than the global average (Savvidou et al., 2021), which suggests greater capacity problems in implementing climate-related projects and, in turn, means lost opportunities to build resilience and adaptive capacity and a wider gap in adaptation finance for Africa (Omari-Motsumi et al., 2019).

The present situation reflects not only an insufficient level of finance being mobilised to support African adaptation needs (Section 9.4.1) but also problems in accessing and using funding that is available. The direct-access modality introduced by the Adaptation Fund and GCF, whereby national and regional entities from developing countries can be accredited to access funds directly, is aimed at reducing transaction costs for recipient countries, increasing national ownership and agency for adaptation actions, and enhancing decision-making responsibilities by national actors, thereby contributing to strengthening local capacity for sustained and transformational adaptation (CDKN, 2013; Masullo et al., 2015). Indeed, direct-access projects from the Adaptation Fund tend to be more community focused than indirect-access projects (Manuamorn and Biesbroek, 2020). Country institutions in Africa, however, are struggling to be accredited for direct access because of the complicated, lengthy and bureaucratic processes of accreditation, which requires, for example, strong institutional and fiduciary standards and capacity to be in place (Brown et al., 2013; Omari-Motsumi et al., 2019). As of December 2019, over 80% of all developing countries had no national direct access entities (DAEs) (Asfaw et al., 2019). Capacity to develop fundable projects in Africa is also inadequate. An analysis of proposals submitted to the GCF up to 2017 revealed that, while African countries were able to submit proposals to the GCF, they had the lowest percentage of approvals (39%) compared to all other regions (Fonta et al., 2018). This suggests the quality of proposals and therefore the capacity to develop fundable proposals remains inadequate in the region.

Even when accredited, some countries experience significant institutional and financial challenges in programming and implementing activities to support concrete adaptation measures (Omari-Motsumi et al., 2019). Low disbursement ratios suggest inadequate capacity to implement projects once they are approved (Savvidou et al., 2021). Systemic barriers have been highlighted in relation to the multilateral climate funds, including funds not providing full-cost adaptation funding, capacity barriers in the design and implementation of adaptation actions (including the development of fundable project proposals) and barriers in recognising and enabling the involvement of sub-national actors in the delivery and implementation of adaptation action (Omari-Motsumi et al., 2019). As of 2017, most GCF disbursements to Africa (61.9%) were directed to support national stakeholders’ engagement with regards to readiness activities, with only 11% directed to support DAEs in implementation of concrete projects/pipeline development (Fonta et al., 2018). While supporting readiness activities is important for strengthening country ownership and institutional development, research suggests adaptation finance needs to shift towards implementation of concrete projects and more pipeline development if the goal of transformative and sustained adaptation in Africa is to be realised (Fonta et al., 2018; Omari-Motsumi et al., 2019). The source of these problems needs to be better understood so that the prospects for future climate-related investments can be improved and institutional strengthening and targeted project preparation can be supported (Omari-Motsumi et al., 2019; Doshi and Garschagen, 2020; Savvidou et al., 2021).

Some progress has been made in supporting developing countries to enhance their adaptation actions. The process to formulate and implement NAPs was established by parties under the UNFCCC to support developing countries in identifying their vulnerabilities, and determine their medium- and long-term adaptation needs (UNFCCC Paris Agreement, 2015). NAPs provide a means of developing and implementing strategies and programmes to address those needs. In 2016, the parties agreed the GCF would fund up to USD 3 million per country for adaptation planning instruments, including NAPs. However, accessing funding through the GCF for NAP formulation is challenging (Fonta et al., 2018) and, as of October 2020, 4 years after the decision to fund NAPs, only six African countries had completed their NAPs (UNFCCC NAP central). The next step is to convert adaptation planning documents into programming pipeline projects that are fundable and implementable, which presents a significant barrier to enhanced adaptation action (Omari-Motsumi et al., 2019).

Adaptation finance has not been targeted more towards more vulnerable countries (Barrett, 2014; Weiler and Sanubi, 2019; Doshi and Garschagen, 2020; Savvidou et al., 2021). Reasons for this include fast-growing middle-income countries offering larger gains in emission reductions, so finance has favoured mitigation in these economies, even within sub-Saharan Africa, and as more climate finance uses debt instruments, mitigation projects are further preferred because returns are perceived to be more certain (Rai et al., 2016; Lee and Hong, 2018; Carty et al., 2020; Simpson et al., 2021c).

Many adaptation interventions for most vulnerable countries and communities provide no adequate financial return on investments and can therefore only be funded with concessional public finance (Cross-Chapter Box FINANCE in Chapter 17). Yet, public funds alone are insufficient to meet rapidly growing adaptation needs. Public mechanisms can help leverage private sector finance for adaptation by reducing regulatory, cost and market barriers through blended finance approaches, public–private partnerships, or innovative financial instruments and structuring in support of private sector requirements for risk and investment returns, such as green bonds (Cross-Chapter Box FINANCE in Chapter 17). Sub-national actors can be core agents to conceptualise, drive and deliver adaptation responses, and unlock domestic resources in the implementation of adaptation action (CoM SSA, 2019; Omari-Motsumi et al., 2019), provided they are sufficiently resourced and their participation and agency are supported.

Many African countries are at high risk of debt distress, especially due to the COVID-19 pandemic, and will need to decrease their debt levels to have the fiscal space to invest in climate resilience (Estevão, 2020; Dibley et al., 2021). As of mid-2021, the G20’s Debt Service Suspension Initiative is providing temporary relief for repayment of bilateral credit, but this has largely not been taken up by private lenders (Dibley et al., 2021; World Bank, 2021). The total external debt-servicing payments combined for 44 African countries in 2019 were USD 75 billion (World Bank, 2019), far exceeding discussed levels of near-term climate finance. Aligning debt relief with Paris Agreement goals could provide an important channel for increased financing for climate action, for example, by allowing African countries to use their debt-servicing payments to finance climate change mitigation and adaptation (Fenton et al., 2014). Governments can disclose climate risks when taking on sovereign debt, and debt-for-climate resilience swaps could be used to reduce debt burdens for low-income countries while supporting adaptation and mitigation (Dibley et al., 2021).

Overcoming governance barriers is a precondition to ensure successful adaptation and CRD (Pasquini et al., 2015; Owen, 2020). Despite the ambitious climate targets across African countries and renewed commitments in recent years (Zheng et al., 2019; Ozor and Nyambane, 2020), governance barriers include, among others, slow policy implementation progress (Shackleton et al., 2015; Taylor, 2016), incoherent and fragmented approaches (Zinngrebe et al., 2020; Nemakonde et al., 2021), inadequate governance systems to manage climate finance (Granoff et al., 2016; Banga, 2019), poor stakeholder participation (Sherman and Ford, 2014), gender inequalities (Andrijevic et al., 2020), unaligned development and climate agendas (Musah-Surugu et al., 2019; Robinson, 2020), elite capture of climate governance systems (Kita, 2019), hierarchical and complex state bureaucracy (Meissner and Jacobs, 2016; Biesbroek et al., 2018) and weak, non-existent or fragmented sub-national institutions (Paterson et al., 2017; Musah-Surugu et al., 2019). Further, adaptation planning involves cross-cutting themes, multiple actors and institutions with different objectives, jurisdictional authority and levels of power and resources, yet there is often a lack of coordination, clear leadership or governance mandates (Shackleton et al., 2015; Leck and Simon, 2018) and unequal power relations between African countries and developed countries can hinder progress on governance of financial markets, budget allocations and technology transfer to address addressing climate technology gaps in Africa (Rennkamp and Boyd, 2015; Olawuyi, 2018).

Policy implementation can be slow due to the absence of support mechanisms and dependency on funding by international partners (Leck and Roberts, 2015; Ozor and Nyambane, 2020). In many countries, commitment to climate policy objectives is low (Naess et al., 2015), particularly in light of competing development imperatives and post-COVID-19 recovery efforts (Caetano et al., 2020), although COVID-19 recovery efforts offer significant opportunities for health, economic and climate resilience co-benefits (Sections 9.4.3; 9.11.5; Cross-Chapter Box COVID in Chapter 7). Another challenge relates to long-term planning and decision making which is hampered by uncertainty related to future socioeconomic and GHG emissions scenarios (Coen, 2021), political cycles and short-term political appointment terms (Pasquini et al., 2015).

Lack of community agency in climate governance affects the capacity for citizen-led climate interventions in Africa (Antwi-Agyei et al., 2015; Mersha and Van Laerhoven, 2016). This is attributed partly to low civic education, limited participation power of citizens and tokenism due to perceived lack of immediate benefits (Odei Erdiaw-Kwasie et al., 2020), as well as low rates of climate change literacy in many regions (Section 9.4.3; Simpson et al., 2021a). Participation in climate policy also extends to the private sector, which has been relatively uninvolved in adaptation discussions to date (Crick et al., 2018).

Africa requires substantial resources and support to adapt to the unavoidable consequences of climate change, a pertinent climate justice concern for governments. However, the mechanisms needed to redress current power imbalances, structural and systemic inequality are often absent (Saraswat and Kumar, 2016; see Section 9.11.4) and policies that underpin environmental justice concerns, including distributive justice, participation, recognition and capability (Shi et al., 2016; Chu et al., 2017) are also needed.

Good governance can contribute to positive climate outcomes and CRD in Africa through long-term planning, development-focused policy environments, the development of robust and transformational policy architecture, inclusive participation and timely implementation of NDCs (Bataille et al., 2016; Werners et al., 2021; see Table 9.3 for examples).

African governments are developing and revising ambitious adaptation policies that are enforceable and aligned with wider societal development goals, including an enabling environment for finance and investment in the jobs and skills development necessary to support a just transition (Section 9.4.5; ILO, 2019). If appropriately designed, such institutions offer the opportunity to foster adaptive governance that is collaborative, multi-level and decentralised, offering integration of policy domains, flexibility and an emphasis on non-coerciveness and adaptation (Ruhl, 2010).

Coordination across multiple sectors, supported with leadership from the highest levels of government, has shown to improve implementation effectiveness and anticipated scaling up (Rigaud et al., 2018). This high-level engagement promotes the inclusion of climate resilience and adaptation targets in national planning and budgeting. Financial and capacity support is essential (Adenle et al., 2017; UNEP, 2021), as is the tracking of national progress towards development goals (Box 9.6).

In Africa, climate governance occurs in a context of deep inequality and asymmetric power relations—both within countries and between countries—making adequate mechanisms for multi-stakeholder participation essential (Sapiains et al., 2021). This requires the creation of avenues for the voices of marginalised groups in policy processes and enabling policy environments that can catalyse inclusive action and transformational responses to climate change (Totin et al., 2018; Revi et al., 2020; Ziervogel et al., 2021), safeguarding protection against the climate harms of the most vulnerable in society, particularly of women and children (see also Box 9.1). Community-based natural resource management in pastoral communities was observed to improve institutional governance outcomes through involving community members in decision making, increasing the capacity of these communities to respond to climate change (Reid, 2014).

Specific indicators can be included in the performance metrics and monitoring frameworks for each sector, policy intervention and budget planning cycle (Wojewska et al., 2021). Many countries in Africa are also revamping their institutional coordination mechanisms to reflect an all-of-government approach and partnership with non-state stakeholders with diverse capabilities and expertise (see examples from Rwanda and Zambia in Table 9.3). This includes Cape Town’s drought response in 2017/2018 where non-state actors actively partnered with the state response around water management/savings practices (Simpson et al., 2020a; 2020b; Cole et al., 2021b).

Table 9.3 | Characteristics and examples of governance that contribute towards CRD in Africa.

Robust legislative frameworks, both climate change specific and non-specific, can foster adaptive responses to climate change, particularly in LDCs (Nachmany et al., 2017). As discussed in Chapter 17, there are many reasons for this. The successful implementation of policy objectives across the continent is often contingent upon or at least supported by an underlying legislative framework (Averchenkova and Matikainen, 2017; Scotford et al., 2017). There are also wider systemic and structural reasons for developing climate change legislation, including the promotion of coordination within government, its policy entrenching role, its symbolic value and its potential to support climate finance flows (Nachmany et al., 2017; Scotford and Minas, 2019).

Legal systems, however, also have the potential to be maladaptive. Laws may be brittle, often assuming and reinforcing a static state, and the boundary of the law may not align to the relevant location, scale or impact (Craig, 2010; Arnold and Gunderson, 2013; Wenta et al., 2019). This necessitates the review and revision of existing laws to remove such barriers and foster adaptive management (Craig, 2010; Ruhl, 2010; Cosens et al., 2017) and, where necessary, the promulgation of new laws.

There has been a rise in framework and sectoral climate change laws across Africa, as illustrated in Figure 9.10. The map illustrates the two framework statutes which have been promulgated in Benin and Kenya, as well as the three framework bills which have been drafted in Nigeria, South Africa and Uganda. There are also discussions taking place in Zimbabwe and Ghana regarding the potential development of a draft framework climate change bill. A review of the climate change framework laws indicates evidence of cross-pollination in design across African jurisdictions, creating the potential for a unique and regionally appropriate body of law with a strong focus on adaptation responses (Rumble, 2019). As discussed in Chapter 17, however, there remains the need for in-country expert input on how the domestic legal landscape may influence their operation, and for each jurisdiction to independently interrogate its adaptation needs and objectives (Scotford et al., 2017).

Numerous African states have also included dedicated climate change-related provisions within various existing statutes that regulate the environment or disaster management. For example, Tanzania’s Environmental Management Act 20 of 2004 contains dedicated provisions to address climate change. Rwanda’s Law on Environment 48/2018 also contains detailed provisions on mainstreaming climate change into development planning processes, education on climate change, vulnerability assessments and the promotion of measures to enhance adaptive capacity. Some countries have also developed laws dedicated to a specific aspect of adaptation. For example, the Conservation and Climate Adaptation Trust of Seychelles Act 18 of 2015 establishes a trust fund to finance climate change adaptation responses in Seychelles. Similarly, many countries including Algeria, Burkina Faso, Djibouti, Ghana, Namibia, Malawi, Mauritius, Madagascar, Mozambique, Tanzania and South Africa have dedicated disaster management laws. At this stage, it is still too early to determine whether these laws are having any substantive influence in strengthening resilience and reducing vulnerability and, as discussed in Chapter 17, this is identified as a knowledge gap requiring further research.

Laws are now being developed to formalise and entrench institutional structures, specifying their mandate, function, membership and related procedures. A useful example of such an approach can be found in the Nigerian Climate Change Bill which establishes the National Climate Council on Climate Change headed and chaired by the Vice-President, with a wide membership of ministers, the Chairmen of the Governors’ Forum and Association of Local Governments, as well as the private sector and non-governmental organisation (NGO) representatives.

Climate change framework laws can play an instrumental role in achieving mainstreaming by directing relevant actors to integrate adaptation considerations into existing mandates, operations and planning instruments (Rumble, 2019). By way of example, the South African Draft Climate Change Bill contains a general duty to ‘coordinate and harmonise the policies, plans, programmes and decisions of the national, provincial and local spheres of government’ to achieve, among other things, the climate change objectives of the Bill and national adaptation objectives.

Another common theme is the requirement to develop national climate change adaptation strategies and plans. Many laws further entrench their longevity by requiring them to be subject to strong community participation and consultation, as demonstrated by the Kenyan Climate Change Act and the Nigerian Climate Change Bill.

The Paris Agreement acknowledges, in Article 7.5, that adaptation should be based on and guided by, among other things, ‘traditional knowledge, knowledge of indigenous peoples and local knowledge systems’. The accumulated knowledge within Indigenous knowledge systems is particularly important as it can assist governments in determining how the climate is changing, how to characterise these impacts and provide lessons for adaptation (Salick and Ross, 2009). In this context, Indigenous knowledge systems can play an important role in the effective design of local laws (Mwanga, 2019), as well as national laws. Doing so can contribute to the success of climate change response strategies, including enhancing local participation and the implementation of community-based and ecosystem-based adaptations (Chanza and de Wit, 2016; Mwanga, 2019). For example, the Makorongo Village Forest Management By-Law in Tanzania codifies local customary practices relating to forest management and sustainable harvesting with associated dual adaptation and mitigation benefits and includes all villagers in the decision-making processes relating to forest management (Mwanga, 2019). The inclusion of beneficial Indigenous knowledge systems within local by-laws is contingent on the active involvement of members of the Indigenous community and awareness of climate change considerations within the local sphere of government, and a willingness to foster such practices (Mwanga, 2019).

In addition to the advancement of Indigenous knowledge in adaptive responses, it has been suggested that the protection of the rights of Indigenous Peoples can have adaptive benefits, in particular through the protection of land tenure rights (Ayanlade and Jegede, 2016). It has been argued that doing so will protect Indigenous Peoples’ lands and resources from overconsumption, secure the recognition of their cultural stewardship over the environment, provide the financial incentive for land stewardship and promote the application of their unique knowledge on the sustainable development of that land and its preservation (Jaksa, 2006; Ayanlade and Jegede, 2016). Not only can a lack of protection of Indigenous legal tenure undermine these objectives, but a number of African laws may actively work against them. For example, a review of Tanzanian and Zambian laws highlighted existing provisions that empowered the state to terminate or criminalise the occupation of vacant, undeveloped or fallow lands, which undermined the occupation by Indigenous peoples of forests and other uncultivated lands (Ayanlade and Jegede, 2016).

Climate services (CS) broadly include the generation, tailoring and provision of climate information for use in decision making at all levels of society (Street, 2016; Vaughan et al., 2018). There is a range of climate service providers in Africa, including primarily National Meteorological and Hydrological Services (NMHS) and partner institutions, complemented by NGOs, the private sector and research institutions (Snow et al., 2016; Harvey et al., 2019), which offer the potential for public–private partnerships (Winrock, 2018; Harvey et al., 2019).

International development funding has progressed the provision of CS and, together with technological advances and capacity-building initiatives, has increased the reliability of CS across Africa (Vogel et al., 2019). Most CS investments have been towards the agricultural sector, with other focal sectors, including pastoralism, health, water, energy and disaster risk reduction, having only small CS initiatives directed towards them (Nkiaka et al., 2019; Carr et al., 2020). Despite this focus and investment, however, there remains a mismatch between the supply and uptake of CS in Africa as information is often inaccessible, unaffordable, not relevant to context or scale, and is poorly communicated (Singh et al., 2018; Antwi-Agyei et al., 2021) (Table 9.4; Sections 9.4.1.5.1 and 9.13.4.1). Observational data required for effective regional CS, including trend analyses, seasonal climate assessment, modelling and model evaluation, is sparse and often of poor quality (Figure 9.11) and usually requires payment which renders it unaffordable (Winrock, 2018).

A number of these challenges can be addressed through the transdisciplinary co-production of CS (Alexander and Dessai, 2019; Vogel et al., 2019; Carter et al., 2020). Co-production of CS involves climate information producers, practitioners and stakeholders, and other knowledge holders participating in equitable partnerships and dialogues to collaboratively identify climate-based risk and develop scale-relevant climate information to address this risk (Table 9.4) (Vincent et al., 2018; Carter et al., 2020).

Table 9.4 | Challenges and opportunities for Climate Services in Africa for the supply and uptake of climate services.

Notes:

(a) Reproduced from Carter et al. (2020) with permission.

However, the effectiveness of co-production processes are hindered by aspects such as inequitable power relationships between different types of knowledge holders (e.g., scientists and practitioners), inequitable distribution of funding between developed country and African partners that favours developed country partners, an inability to develop sustained trust relationships as a result of short-funding cycles, a lack of flexibility due to product-focused engagements and the scalability of co-production to enable widespread reach across Africa as the process is usually context specific (high confidence) (Vincent et al., 2018; Vogel et al., 2019; 2020a).

Despite these challenges, the inclusive nature of co-production has had a positive influence on the uptake of CS into decision making where it has been applied (Table 9.4; Figure 9.12; Vincent et al., 2018; Vogel et al., 2019; Carter et al., 2020; Chiputwa et al., 2020) (medium confidence), through sustained inter/transdisciplinary relationships and capacity development (Norström et al., 2020), strategic financial investment, fostering of ownership of resulting products and the combining of scientific and other knowledge systems (Carter et al., 2020; Steynor et al., 2020a). There is high confidence that together with improved institutional capacity building and strategic financial investment, CS can help African stakeholders adapt to projected climate risks (Figure 9.11).

Perceptions of climate variability and change affect whether and how individuals and institutions act, and thus contribute to the success or failure of adaptation policies related to weather and climate (Silvestri et al., 2012; Arbuckle et al., 2015; Simpson et al., 2021a).

A recent Afrobarometer study covering 34 African countries found 67% of Africans perceive climate conditions for agricultural production to have worsened over time, and report drought as the main extreme weather event to have worsened in the past decade (Selormey et al., 2019). Of these participants, across all socioeconomic strata, 71% of those who were aware of the concept of climate change agreed that it needs to be stopped, but only 51% expressed confidence about their ability to make a difference. East Africans (63%) were almost twice as likely as north Africans (35%) to report that the weather for growing crops had worsened. Additionally, people engaged in occupations related to agriculture (farming, fishing or forestry) were more likely to report negative weather effects (59%) than those with other livelihoods (45%) (Selormey et al., 2019). Similar perceptions have been reported among a diversity of rural communities in many sub-Saharan African countries (Mahl et al., 2020; Simpson et al., 2021a).

Rural communities, particularly farmers, are the most studied groups for climate change perception. They perceive the climate to be changing, most often reporting changes in rainfall variability, increased dry spells, decreases in rainfall and increased temperatures or temperature extremes. They perceive these changes to bring a range of negative socioeconomic and environmental effects (Alemayehu and Bewket, 2017; Liverpool-Tasie et al., 2020; Simpson et al., 2021a). In some cases, farmers’ perceptions of changes in weather and climate frequently match climate records for decreased precipitation totals, increased drought frequency, shorter rainy season and rainy season delay, and increased temperatures (Figure 9.11; Rurinda et al., 2014; Boansi et al., 2017; Ayanlade et al., 2018), but not in all cases or not for all perceived changes, with common discrepancies in perceived lower rainfall totals (Alemayehu and Bewket, 2017; Ayal and Leal Filho, 2017; Simpson et al., 2021a).

Farming experience, access to extension services and increasing age are the most frequently cited factors positively influencing the perceptions of climate changes (Alemayehu and Bewket, 2017; Oduniyi and Tekana, 2019). Personal experience of climate-related changes and their impacts appears to be an important factor influencing perceptions through shaping negative associations, for example, experience of flash floods (Elshirbiny and Abrahamse, 2020) or direct effect on economic activity, indicating that perception is not restricted to crop farmers (Liverpool-Tasie et al., 2020). However, perceptions show common misconceptions about the causes of climate change, which has implications for climate action (Elshirbiny and Abrahamse, 2020), highlighting the importance of climate change literacy.

Understanding the human cause of climate change is a strong predictor of climate change risk perception (Lee et al., 2015) and a critical knowledge foundation that can affect the difference between coping responses and more informed and transformative adaptation (Figure 9.11; Oladipo, 2015; Mutandwa et al., 2019). At a minimum, climate change literacy includes both having heard of climate change and understanding it is, at least in part, caused by people (Simpson et al., 2021a). However, large inequalities in climate change literacy exist between and within countries and communities across Africa.

The average national climate change literacy rate in Africa is only 39% (country rates range from 23–66%) (Figure 9.11). Of 394 sub-national regions surveyed by Afrobarometer, 8% (37 regions in 16 countries) have a climate change literacy rate lower than 20%, while only 2% (8 regions) score higher than 80%, which is common across European countries (Simpson et al., 2021a). Striking differences exist when comparing sub-national units within countries. Climate change literacy rates in Nigeria range from 71% in Kwara to 5% in Kano, and within Botswana from 69% in Lobatse to only 6% in Kweneng West (Simpson et al., 2021a). Education is the strongest positive predictor of climate change literacy, particularly tertiary education, but poverty decreases climate change literacy and climate change literacy rates average 12.8% lower for women than men (Simpson et al., 2021a).

As the identified factors driving climate change literacy overlap with broader developmental challenges on the continent, policies targeting these factors (e.g., increased education) can potentially yield co-benefits for both climate change adaptation as well as progress towards SDGs, particularly education and gender equality (Simpson et al., 2021a). Progress towards greater climate change literacy affords a concrete opportunity to mainstream climate change within core national and sub-national developmental agendas in Africa towards more CRD pathways. Synergies with CS can also overcome gendered deficits, for example, although women are generally less climate change aware and more vulnerable to climate change than men in Africa, they are generally more likely to adopt climate-resilient crops when they are climate change aware and have exposure to extension services (Acevedo et al., 2020; Simpson et al., 2021a).

Sustained station observation networks (Figure 9.15) are essential for the long-term analysis of local and regional climate trends, including for temperature and rainfall, as well as: the calibration of satellite-derived climate products; development of gridded climate datasets using interpolated and blended station–satellite products that form the baseline from which climate change departures are measured; development and running of early warning systems; climate projection and impact studies; and extreme event attribution studies (Harrison et al., 2019; Otto et al., 2020).

However, production of salient climate information in Africa is hindered by limited availability of and access to weather and climate data, especially in central and north Africa (Figure 9.15; Coulibaly et al., 2017; Hansen et al., 2019a). Existing weather infrastructure remains suboptimal for development of reliable early warning systems (Africa Adaptation Initiative, 2018; Krell et al., 2021). For example, it is estimated only 10% of the world’s ground-based observation networks are in Africa, and that 54% of Africa’s surface weather stations cannot capture data accurately (Africa Adaptation Initiative, 2018; World Bank, 2020d). Some programmes are trying to address this issue, including the trans-African hydro-meteorological observatory (van de Giesen et al., 2014), the West African Science Service Centre on Climate Change and Adaptive Land Management (WASCAL) (Salack et al., 2019), the Southern African Science Service Centre for Climate Change, Adaptive Land Management (SASSCAL) (Kaspar et al., 2015) and the AMMA-CATCH National Observation Service and Critical Zone Exploration Network (Galle et al., 2018). However, the sustainability of observation networks beyond the life of these programmes is uncertain as many African National Meteorological and Hydrology Services experience structural, financial and technical barriers to maintaining these systems (Section 9.4.5).

The overall continental trend is woody plant expansion, particularly in grasslands and savannas, with woody plant cover increasing at a rate of 2.4% per decade (see Figure 9.17; Stevens et al., 2017; Axelsson and Hanan, 2018). There is also increased grass cover in arid regions in southwestern Africa (Masubelele et al., 2014). There is high agreement that this is attributable to increased CO2, warmer and wetter climates, declines in burned area and release from herbivore browsing pressure, but the relative importance of these interacting drivers remains uncertain (O’Connor et al., 2014; Stevens et al., 2016; García Criado et al., 2020). Woody encroachment is the dominant trend in the western and central Sahel, occurring over 24% of the region, driven primarily by shifts in rainfall timing and recovery from drought (Anchang et al., 2019; Brandt et al., 2019). Remote sensing studies demonstrate greening in southern Africa and forest expansion into water-limited savannas in central and west Africa (Baccini et al., 2017; Aleman et al., 2018; Piao et al., 2020), with increases in precipitation and atmospheric CO2 the probable determinants of change (Venter et al., 2018; Brandt et al., 2019; Zhang et al., 2019). These trends of greening and woody plant expansion stand in contrast to the desertification and contraction of vegetated areas highlighted in AR5 (Niang et al., 2014), but are based on multiple studies and longer time series of observations. Reported cases of desertification and vegetation loss, for example, in the Sahel, appear transitory and localised rather than widespread and permanent (Dardel et al., 2014; Pandit et al., 2018; Sterk and Stoorvogel, 2020).

Shifts in demography, geographic ranges, and abundance of plants and animals consistent with expected impacts of climate change are evident across Africa. These include uphill contractions of elevational range limits of birds (Neate-Clegg et al., 2021), changes in species distributions previously reported in AR5 (Niang et al., 2014) and the death of many of the oldest and largest African baobabs (Patrut et al., 2018). An increase in frequency and intensity of hot, dry weather after wildfires has led to a long-term decline in plant biodiversity in Fynbos since the 1960s (Slingsby et al., 2017). Increasing temperatures may have contributed to the declining abundance and range size of South African birds (Milne et al., 2015), including Cape Rockjumper (Chaetops frenatus) and protea canary (Serinus leucopterus), from increased risk of reproductive failure (Lee and Barnard, 2016; Oswald et al., 2020). For hot and dry regions (e.g., Kalahari), there is strong evidence that increased temperatures are having chronic sublethal impacts, including reduced foraging efficiency and loss of body mass (du Plessis et al., 2012; Conradie et al., 2019), and are approaching species physiological limits, with heat extremes driving mass mortality events in birds and bats (McKechnie et al., 2021). Vegetation change linked to climate change and increasing atmospheric CO2 has had an indirect impact on animals. Increased woody cover has decreased the occurrence of bird, reptile and mammal species that require grassy habitats (Péron and Altwegg, 2015; McCleery et al., 2018). Decreased fruit production linked to rising temperatures has decreased the body condition of fruit-dependent forest elephants by 11% from 2008–2018 (Bush et al., 2020).

There is high agreement that land use activities counteract or exacerbate climate-driven vegetation change (Aleman et al., 2017; Timm Hoffman et al., 2019). Decreased woody plant biomass in 11% of sub-Saharan Africa was attributed to land clearing for agriculture (Brandt et al., 2017; Ordway et al., 2017). Localised loss of tree cover in Miombo woodlands and 16.6±0.5 Mha of forest loss in the Congo Basin between 2000–2014 was driven largely by forest clearing and drought mortality (McNicol et al., 2018; Tyukavina et al., 2018).

Vegetation changes interacting with climate and land use change have impacted fire regimes across Africa. The frequency of weather conducive for fire has increased in southern and west Africa and is expected to continue increasing in the 21st century under both RCP2.6 and RCP8.5 (Betts et al., 2015; Abatzoglou et al., 2019). Increased grass cover in arid regions introduced fire into regions where fuel was previously insufficient to allow fire spread, such as the arid Karoo in South Africa (du Toit et al., 2015; Strydom and Savage, 2016). In contrast, shrub encroachment, increased precipitation (Zubkova et al., 2019), vegetation fragmentation and cropland expansion have reduced fire activity in many African grasslands and savannas (Andela and van der Werf, 2014; Probert et al., 2019). These drivers are expected to negate the effect of increasing fire weather and ultimately lead to a reduction in the total burned area under RCP4.5 and RCP8.5 (Knorr et al., 2016; Moncrieff et al., 2016; Wu et al., 2016).

African ecosystems have a long evolutionary association with fire, large mammal herbivory and drought (Maurin et al., 2014; Charles-Dominique et al., 2016). The maintenance of biodiversity depends on natural disturbance regimes. Natural regrowth of savanna plant biomass in southern Africa compensated for biomass removal through human activities (McNicol et al., 2018), and rapid recovery occurred after the 2014–2016 extreme drought (Abbas et al., 2019). During the same drought event, browsing and mixed feeder herbivores were resilient, but grazers declined by approximately 60% and were highly dependent on drought refugia (Abraham et al., 2019). African tropical forests remained a carbon sink through the record drought and temperature experienced in the 2015–2016 El Niño, indicating resilience in the face of extreme environmental conditions (Bennett et al., 2021). This is likely due to the presence of drought-tolerant species and floristic and functional shifts in tree species assemblages (Fauset et al., 2012; Aguirre-Gutiérrez et al., 2019). This resilience indicates that there is the capacity to recover from disturbances and short-term change. However, resilience has limits and beyond certain points, change can lead to irreversible shifts to different states (Figure 9.18).

Small climatic variations have large impacts on ecosystem function in Africa’s freshwaters (Ndebele-Murisa, 2014; Ogutu-Ohwayo et al., 2016). Warming of water temperatures from 0.2°C to 3.2°C occurred in several lakes over 1927–2014 and has been attributed to human-caused climate change (Figure 9.17; Ogutu-Ohwayo et al., 2016). Increased temperature, changes in rainfall and reduced wind speed altered the physical and chemical properties of inland water bodies, affecting water quality and productivity of algae, invertebrates and fish (high confidence). In deeper lakes, warmer surface waters and decreasing wind speeds reduced shallow waters mixing with nutrient-rich deeper waters, reducing biological productivity in the upper sunlit zone (Ndebele-Murisa, 2014; Saulnier-Talbot et al., 2014). In several lakes, climate change was identified as causing changes in insect emergence time (Dallas and Rivers-Moore, 2014) and in loss of fish habitats (Natugonza et al., 2015; Gownaris et al., 2016). This set of changes can harm human livelihoods, for example, from reduced fisheries productivity (see Section 9.8.5; Ndebele-Murisa, 2014; Ogutu-Ohwayo et al., 2016) and reduced water supply and quality (Section 9.7.1).

Anthropogenic climate change is already negatively impacting Africa’s marine biodiversity, ecosystem functioning and services by changing physical and chemical properties of seawater (increased temperature, salinity and acidification, and changes in oxygen concentration, ocean currents and vertical stratification) (high confidence) (Hoegh-Guldberg et al., 2014; 2018). Coastal ecosystems in west Africa are among the most vulnerable because of extensive low-lying deltas exposed to sea level rise, erosion, saltwater intrusion and flooding (Belhabib et al., 2016; UNEP, 2016b; Kifani et al., 2018). In southern Africa, shifting distributions of anchovy, sardine, hake, rock lobster and seabirds have been partly attributed to climate change (Crawford et al., 2015; van der Lingen and Hampton, 2018; Vizy et al., 2018), including southern shifts of 30 estuarine and marine fish species attributed to increased temperature and changes in water circulation from decreased river inflow (Augustyn et al., 2018). Warming sea surface temperatures inhibiting nutrient mixing have reduced phytoplankton biomass in the western Indian Ocean by 20% since the 1960s, potentially reducing tuna catches (Roxy et al., 2016).

Mangroves, seagrasses and coral reefs support nursery habitats for fish, sequester carbon, trap sediment and provide shoreline protection (Ghermandi et al., 2019). Climate change is compromising these ecosystem services (medium confidence). Marine heatwaves associated with ENSO events have triggered mass coral bleaching and mortality over the past 20 years (Oliver et al., 2018). Mass coral bleaching in the western Indian Ocean occurred in 1998, 2005, 2010 and 2015/2016 with coral cover just 30–40% of 1998 levels by 2016 (Obura et al., 2017; Moustahfid et al., 2018). The northern Mozambique Channel has served as a refuge from climate change and biological reservoir for the entire coastal east African region (McClanahan et al., 2014; Hoegh-Guldberg et al., 2018). A southern shift of mangrove species has been observed in south Africa (Peer et al., 2018) with loss in total suitable coastal habitats for mangroves and shifts in the distribution of some species of mangroves and a gain for others (Record et al., 2013). Mangrove cover was reduced 48% in Mozambique in 2000 from Tropical Cyclone Eline, with 100% mortality of seaward mangroves dominated by Rhizophora mucronata (Macamo et al., 2016). Recovery of mangrove species was observed 14 years later in sheltered sites. There is low confidence these cyclone-induced impacts are attributable to climate change owing, in part, to a lack of reliable long-term data sets (Macamo et al., 2016). In west Africa, oil and gas extraction, deforestation, canalisation and de-silting of waterways have been the largest factors in mangrove destruction (Numbere, 2019).

The geography of African biomes is projected to shift due to changes in atmospheric CO2 concentrations and aridity (Figure 9.18). Grassland expansion into the desert, woody expansion into grasslands and forest expansion into savannas are projected for areas of reduced aridity, caused by reduced moisture stress from CO2 fertilisation under medium (RCP4.5) and high (SRES A2) emissions scenarios (Heubes et al., 2011; Moncrieff et al., 2016). This greening trend may slow or reverse with continued temperature increase and/or in areas of increased aridity (Berdugo et al., 2020). The net impact of these effects on vegetation is highly uncertain (Trugman et al., 2018; Cook et al., 2020a; Martens et al., 2021). The maintenance or re-establishment of natural fire and large mammal herbivory processes can mitigate projected CO2 and climate-driven changes (Scheiter and Savadogo, 2016; Stevens et al., 2016). Expansion of croplands and pastures will reduce ecosystem carbon storage in Africa, potentially reversing climate- and CO2-driven greening in savannas (Aleman et al., 2018; Quesada et al., 2018).

Vegetation growth simulated by dynamic vegetation models is often highly sensitive to CO2 fertilisation. These models project the African tropical forest carbon sink to be stable or strengthened under scenarios of future climate change (Huntingford et al., 2013; Martens et al., 2021). In contrast, statistical modelling suggests it has begun to decline and will weaken further, decreasing from current estimates of 0.66 tonnes of carbon removed from the atmosphere per hectare per year to 0.55 tonnes of carbon (Hubau et al., 2020). Increasing rainfall seasonality and aridity over central Africa (Haensler et al., 2013) threatens the massive carbon store in the Congo Basin’s Cuvette Centrale peatlands, estimated at 30.6 billion tonnes (Dargie et al., 2019).

Local extinction is when a species is extirpated from a local site. The magnitude and extent of local extinctions predicted across Africa increase substantially under all future GWLs (high confidence) (Table 9.5; Figure 9.19). Above 2°C, the risk of sudden disruption or loss of local biodiversity increases and becomes more widespread, especially in central, west and east Africa (Trisos et al., 2020).

Global extinction is when a species is extirpated from all areas. At 2°C global warming, 11.6% of African species (mean 11.6%, 95% CI 6.8–18.2%) assessed are at risk of global extinction, placing Africa second only to South America in the magnitude of projected biodiversity losses (Urban, 2015). At >2°C, 20% of north African mammals may lose all suitable climates (Soultan et al., 2019), and over half of the dwarf succulents in South African Karoo may lose >90% of their suitable habitat (Young et al., 2016). Among the thousands of species at risk, many are species of ecological, cultural and economic importance such as African wild dogs (Woodroffe et al., 2017) and Arabica coffee (Moat et al., 2019).

With increasing warming, there is a lower likelihood species can migrate rapidly enough to track shifting climates, increasing global extinction risk and biodiversity loss across more of Africa (high confidence). Immigration of species from elsewhere may partly compensate for local extinctions and lead to local biodiversity gains in some regions (Newbold, 2018; Warren et al., 2018). However, more regions face net losses than net gains. At 1.5°C global warming, >46% of localities face net declines in vertebrate species richness of >10%, with net increases projected for less than 15% of localities (Barbet-Massin and Jetz, 2015; Newbold, 2018). At >2°C, 9% of species face complete range loss by 2100, regardless of their dispersal ability (Urban, 2015). With >4°C global warming, a net loss of >10% of vertebrate species richness is projected across 85% of Africa (Barbet-Massin and Jetz, 2015; Mokhatla et al., 2015; Newbold, 2018; Warren et al., 2018). Mountain top endemics and species in north and southern Africa are at risk due to disappearing cold climates (Milne et al., 2015; Garcia et al., 2016; Bentley et al., 2018; Soultan et al., 2019). For hot regions such as the Sahara, Congo Basin and Kalahari, no warmer-adapted species are available elsewhere to compensate for local extinctions, so the resilience of local biodiversity will depend entirely on the persistence of species (Burrows et al., 2014; Garcia et al., 2014). The capacity for species to avoid extinction through behavioural thermoregulation, plasticity or evolution is uncertain but will become increasingly unlikely under higher warming scenarios (Conradie et al., 2019).

Table 9.5 | Risk of local extinction increases across Africa with increasing global warming.

African coastal and marine ecosystems are highly vulnerable to climate change (high confidence). At 1.5°C of global warming, mangroves will be exposed to sedimentation and sea level rise, while seagrass ecosystems will be most affected by heat extremes (high confidence) (Hoegh-Guldberg et al., 2018) and turbidity (Wong et al., 2014). These risks will be amplified at 2°C and 3°C (virtually certain) (Hoegh-Guldberg et al., 2018). Over 90% of east African coral reefs are projected to be destroyed by bleaching at 2°C of global warming (very high confidence) (Hoegh-Guldberg et al., 2018). At around 2.5°C global warming, an important reef-building coral (Diploastrea heliopora) in the central Red Sea is projected to stop growing altogether (Cantin et al., 2010). By 2.5°C, suitable habitat of >50% of species are projected to decline for coastal lobster in east and north Africa, with large declines for the commercially important lobster species Jasus lalandii in southern Africa (Boavida-Portugal et al., 2018). More generally, tropical regions, especially exclusive economic zones in west Africa, are projected to lose large numbers of marine species and may experience sudden declines with extratropical regions having potential net increases as species track shifting temperatures poleward (García Molinos et al., 2016; Trisos et al., 2020).

Above 2°C global warming, the proportion of freshwater fish species vulnerable to climate change increases substantially (high confidence) (Figure 9.19). At 2°C, 36.4% of fish species are projected to be vulnerable to local or global extinction by 2100, increasing to 56.4% under 4°C warming (average of values from (Nyboer et al., 2019; Barbarossa et al., 2021) (Figure 9.19). Global warming reduces available habitat for freshwater species due to reduced precipitation and increased drought leading to increasing water temperatures above optimal physiological limits in floodplains, estuaries, wetlands, ephemeral pools, rivers and lakes (Dalu et al., 2017; Kalacska et al., 2017; Nyboer and Chapman, 2018). Along the Zambezi River, projected flow reductions could cause a 22% reduction in annual spawning habitat and depletion of food resources for fry and juvenile fish that could impede fish migration and reduce stocks (Kangalawe, 2017; Martínez-Capel et al., 2017; Tamatamah and Mwedzi, 2020). More aquatic species will have the capacity to cope with 2°C compared to 4°C global warming, with more negative effects on physiological performance at 4°C (Dallas, 2016; Pinceel et al., 2016; Zougmoré et al., 2016; Nyboer and Chapman, 2017; Ross-Gillespie et al., 2018). Endemic, specialised fish species will have a lower capacity to adjust to elevated water temperatures compared to hardier generalist fishes (McDonnell and Chapman, 2015; Nyboer and Chapman, 2017; Lapointe et al., 2018; Reizenberg et al., 2019). More work is needed to understand the risk for invertebrates (Dallas and Rivers-Moore, 2014; Cohen et al., 2016), and to understand the potential effects of reduced mixing of water and other climate risks on freshwater biodiversity.

Direct human dependence on provisioning ecosystem services in Africa is high (Egoh et al., 2012; IPBES, 2018). For example, natural forests provided 21% of rural household income across 11 African countries (Angelsen et al., 2014) and wild-harvested foods (including fisheries) provide important nutrition to millions of Africans, including through important micronutrients and increased dietary diversity (Sections 9.8.2.3; 9.8.5; Powell et al., 2013; Baudron et al., 2019a).

Climate change has affected ecosystem services in Africa by reducing fish stocks, crop and livestock productivity, and water provisioning due to heat and drought (see Sections 9.8.2.1; 9.8.2.2; 9.8.2.4; 9.8.5.1). Woody encroachment is decreasing cattle production and water supply (Smit and Prins, 2015; Stafford et al., 2017), but can also provide forage for goat production, as well as resins, fuelwood and charcoal (Reed et al., 2015; Stafford et al., 2017; Charis et al., 2019). Local communities perceive climate change to have decreased crop and livestock productivity, reduced wild food availability and reduced forest resources across Africa (see Sections 9.8.2.1; 9.8.2.2; 9.8.2.4; 9.8.2.3; Onyekuru and Marchant, 2014).

With global warming >3°C, and with high population growth and agricultural expansion (SSP3, 2081–2100), 1.2 billion Africans are projected to be negatively affected by pollution of drinking water from reduced water quality regulation by ecosystems and 27 million people affected by reduced coastal protection by ecosystems (Chaplin-Kramer et al., 2019). The number of people affected reduces to 0.4 billion and 22 million, respectively, under a sustainable development scenario with global warming below 2°C (SSP1, 2081–2100). The African tropical forest carbon sink has been more resilient than Amazonia to recent warming but may already have peaked, and this service is predicted to decline with further warming, reducing 14% by the 2030s (Hubau et al., 2020; Sullivan et al., 2020). This declining carbon storage may be offset by CO2 fertilization (low confidence) (Martens et al., 2021). Climate change is projected to shift the geographic distribution of important human and livestock disease vectors (see Sections 9.8.2.4; 9.10.2). Changes in rainfall seasonality compounded with land privatisation and population growth may adversely impact nomadic and semi-nomadic pastoralists who follow shifting patterns of greening vegetation (Van Der Ree et al., 2015).

Invasive species threaten African ecosystems and livelihoods (Ranasinghe et al., 2021). For instance, economic impacts were estimated at USD 1 billion per year for smallholder maize farmers in east Africa (Pratt et al., 2017). Climate change is projected to change patterns of invasive species spread (high confidence). The area of suitable climate for Lantana camara is projected to contract (Taylor et al., 2012) and to expand for Prosopis juliflora (Sintayehu et al., 2020). Bioclimatic suitability for fall armyworm, a major threat to maize, is projected to decrease in central Africa but expand in southern and west Africa (Zacarias, 2020), and to expand for coffee berry borer (Hypothenemus hampei) in Uganda and around Mount Kenya (Jaramillo et al., 2011). Climate suitability for tephritid fruit flies is projected to decrease in central Africa (Hill et al., 2016). Increased water temperature is projected to favour invasive over local freshwater fish populations and shift the range of invasive aquatic plants in South Africa (Hoveka et al., 2016; Shelton et al., 2018). Alterations to lake and river connectivity are predicted to modify invasion pathways in Lake Tanganyika and water hyacinth coverage may increase with warmer waters in Lake Victoria (Masters and Norgrove, 2010; Plisnier et al., 2018).

African protected areas store around 1.5% of global land ecosystem carbon stocks and support biodiversity (Gray et al., 2016; Melillo et al., 2016; Sala et al., 2018). They also support livelihoods and economies, such as through nature-based tourism and improved fisheries (Brockington and Wilkie, 2015; Mavah et al., 2018; Ban et al., 2019).

Climate change and land use change will interact to influence the effectiveness of African protected areas (high confidence). Species representation in the existing African protected area network is projected to decrease due to species range shifts for mammals, bats, birds and amphibians (Hole et al., 2009; Baker et al., 2015; Payne and Bro-Jørgensen, 2016; Smith et al., 2016; Phipps et al., 2017). Species ability to disperse between areas to track shifting climates is increasingly impaired by land transformation and fencing, which also impact seasonal wildlife migrations (Lovschal et al., 2017; Sloan et al., 2017). On land, only 0.5% of the African protected area network is connected through low-impact landscapes (Ward et al., 2020). Linear transport infrastructure (e.g., roads, railways, pipelines) and fencing from proposed ‘development corridors’ are projected to bisect over 400 protected areas and degrade around 1800 more (Laurance et al., 2015). Climate change could increase human–wildlife conflict as resultant resource shortages cause communities to move into protected areas for harvesting or livestock grazing, or wildlife to move out of protected areas and into contact with people (Mukeka et al., 2018; Kupika et al., 2019; Hambira et al., 2020). See Section 9.6.4 for the role of land and ocean protected areas in climate change adaptation.

Improved ecosystem care and restoration are cost-effective for carbon sequestration while providing multiple environmental, social and economic co-benefits (Griscom et al., 2017; Shukla et al., 2019). Protecting and restoring natural forests and wetlands reduces flood risk across multiple African countries (Bradshaw et al., 2007). In Kenya, enclosures for rangeland regeneration diversified income sources, which could increase the adaptive capacity of local people (Mureithi et al., 2016; Wairore et al., 2016). Sustainable agroforestry in semi-arid regions provides income sources from fuelwood, fruit and timber and reduces exposure to drought, floods and erosion (Quandt et al., 2017). Forest protection in Zimbabwe maintains honey production during droughts, providing food supply options if crops fail (Lunga and Musarurwa, 2016). Community-based natural resource management in pastoral communities improved institutional governance outcomes through involving community members in decision making, increasing the capacity of these communities to respond to climate change (Reid, 2014).

EbA can also increase ecological resilience. Re-introduction of fire and large mammals can restore ecosystem services, enhance adaptive capacity and benefit people by combatting woody encroachment, restoring grazing and increasing streamflow (Asner et al., 2016; Stafford et al., 2017; Cromsigt et al., 2018). Herbivores can also reduce fuel loads in areas facing increased fire risk (Hempson et al., 2017).

Protected areas can be ‘stepping stones’ that facilitate climate-induced species range shifts (Roberts et al., 2020), preserve medicinal plant diversity despite climate change (Kaky and Gilbert, 2017) and provide livelihood diversification opportunities (Table 9.6). Protecting 30% of sub-Saharan Africa’s land area could reduce the proportion of species at risk of extinction by around 60% in both low and high warming scenarios (Hannah et al., 2020). The role of protected areas in EbA can be strengthened by: (a) increasing coverage of diverse environments and high carbon storage ecosystems, (b) restoring habitat, (c) maintaining intact habitat, (d) participatory, equitable conservation and adaptation strategies; (e) cooperating across borders and (f) adequate monitoring (Gillson et al., 2013; Rannow et al., 2014; Midgley and Bond, 2015; Pecl et al., 2017; Dinerstein et al., 2019; Roberts et al., 2020).

EbA can mitigate flooding and increase the resilience of freshwater ecosystems (Table 9.6). Adaptation in African freshwater ecosystems is heavily influenced by non-climate anthropogenic factors, including land use change, water abstraction and diversion, damming and overfishing (Dodds et al., 2013; Kimirei et al., 2020; UNESCO and UN-Water, 2020). Wetlands and riparian areas support biodiversity, act as natural filtration systems and serve as buffers to changes in the hydrological cycle, thereby increasing the resilience of freshwater ecosystems and the people that rely on them (Ndebele-Murisa, 2014; Musinguzi et al., 2015; Lowe et al., 2019). However, national adaptation programmes of action, NAPs and national communications rarely consider the ecological stability of ecosystems safeguarding the very water resources they seek to preserve (Kolding et al., 2016). Some countries have mandated the protection of riparian zones, but implementation is low (Musinguzi et al., 2015; Muchuru and Nhamo, 2018). Protecting terrestrial areas surrounding Lake Tanganyika benefited fish diversity (Britton et al., 2017). Afforestation reduces water availability but forest restoration and removing invasive plant species can increase water flows in regions facing water insecurity from climate change (Chausson et al., 2020; Le Maitre et al., 2020). Regular, long-term monitoring of African freshwaters would improve understanding of responses to climate change. General principles for this type of monitoring were developed for Lake Tanganyika (Plisnier et al., 2018) and could be applied to develop harmonised, regional monitoring of African lakes, rivers and wetlands (Tamatamah and Mwedzi, 2020)

Marine and coastal ecosystems such as mangroves, seagrass and coral reefs provide storm protection and food security for coastal communities (high confidence) (IPCC, 2019d). Restoring reef systems reduced wave height in Madagascar (Narayan et al., 2016), but there is limited evidence for the efficacy of coral reef restoration at large scales with increased warming (Chapter 3 Section 3.6.3). Populations at risk from storm surge and/or sea level rise coincide with areas of high coastal EbA potential from Mozambique to Somalia, and coastlines of the Gulf of Guinea, Gambia, Guinea-Bissau and Sierra Leone (Jones et al., 2020). Understanding hotspots of EbA potential is particularly important for west Africa with some of the highest levels of human dependence on marine ecosystems at high risk from climate change and large populations vulnerable to sea level rise (Sections 9.9.3.1; 9.8.5.2; Selig et al., 2018; Trisos et al., 2020).

Marine protected areas (MPAs) can yield multiple adaptation benefits, such as buffering species from extinction and increasing fish stocks, as well as storing large amounts of carbon (Edgar et al., 2014; Roberts et al., 2017; Lovelock and Duarte, 2019). However, this potential of MPAs will reach limits with increased warming (Roberts et al., 2017). For example, MPAs cannot prevent coral bleaching at scale and mass die-offs are well-described from MPAs following climate shocks (Bates et al., 2019; Bruno et al., 2019). However, prioritising MPA coverage of climate refugia, such as the Northern Mozambique Channel, may offer some increased resilience (McClanahan et al., 2014).

By 2050, up to 921 million additional people in sub-Saharan Africa could be exposed to climate change-related water stress, while up to 459 million could experience reduced exposure (Dickerson et al., 2021). This large variance in numbers and direction of change is related to uncertainties in climate models and non-climate factors like population growth and water withdrawals (Dickerson et al., 2021). The baseline for most of the projected risks presented here is 1971–2000.

In west Africa, significant spatial variability in river flow is projected in the upper reaches of several rivers, with no clear pattern overall (Roudier et al., 2014) and large uncertainties in estimations of change in runoff (Roudier et al., 2014; Bodian et al., 2018). In some higher altitude regions, like the Niger Inland Delta in west Africa, river flows and water levels are expected to increase (medium confidence) (Aich et al., 2014; Thompson et al., 2017). In the Lower Niger Basin, combined average annual rainfall and erosivity for all the climatic models in all scenarios shows increasing rainfall amounts are projected to result in an increasing average change in rainfall-runoff erosivity of about 14%, 19% and 24% for the 2030s, 2050s and 2070s, with concomitant increase in soil loss of 12%, 19% and 21% (Amanambu et al., 2019). In the Volta River system, increasing wet season river flows (+36% by 2090s) and Volta lake outflow (+5% by 2090s) are anticipated under RCP8.5 (medium confidence) (Awotwi A et al., 2015; Jin et al., 2018). In the Volta River basin, compared to 1976–2005, drought events are projected to increase by 1.2 events per decade at around 2°C to 1.6 events per decade at around 2.5°C global warming, and drought area extent is projected to increase by 24% to 34% (Oguntunde et al., 2017). In central Africa, runoff in the Congo river system may increase by up to 50% (RCP8.5), especially in the wet season, enhancing flood risks in the entire Congo Basin, particularly in the central and western parts (CSC, 2013). Average river flows are expected to increase in most parts of central Africa, with expected increases in total potential hydropower production (Ludwig et al., 2013), but see Box 9.5.

In north Africa, in the upper White Nile basin, Olaka et al. (2019) project a 25% and 5–10% (RCP4.5) increase in the intensification of future annual rainfall in the eastern and western parts of the Lake Victoria Basin, respectively, with corresponding variability in future river discharge ranging from 5% to 26%. In the upper Blue Nile basin, models also indicate up to 15% increase in runoffs in wet season and up to −24% decrease in dry season during 2021–2040 (RCP8.5) (Ayele et al., 2016; Siam and Eltahir, 2017; Meresa and Gatachew, 2018). The increase of precipitation in the wet season indicates a higher possibility of flash floods, while decreased runoffs in dry season further intensify existing shortage of irrigation water demand (Ayele et al., 2016; Siam and Eltahir, 2017; Meresa and Gatachew, 2018). The annual flow and revenues from hydropower production and irrigated agriculture of the Blue Nile River at Khartoum are projected to increase under maximum but are expected to decrease under minimum and median projected changes in streamflow for 2041–2070 and 2071–2100, respectively (Tariku et al., 2021). The Middle Draa valley in Morocco is expected to experience more severe droughts and the estimation of the water balance suggests a lack of supply in the future (Karmaoui et al., 2016).

In east Africa, Liwenga et al. (2015) project warmer and wetter conditions in the Great Ruaha River region and with increasing seasonal variation and extremes towards the end of the century. A similar observation is made for the River Pangani, with mean river flow being about 10% higher in the 2050s relative to the 1980–1999 period, associated with a 16–18% increase in rainfall in its upper catchment (Kishiwa et al., 2018). However, at more local scales, the projections cover a range of slight declines to significant increases in mean annual rainfall amounts (Gulacha and Mulungu, 2017). In the Tana River basin in Kenya, water yield is projected to increase progressively under RCP4.5 and RCP8.5 relative to the baseline period 1983–2011 but is characterised by distinct spatial heterogeneity (Muthuwatta et al., 2018).

In southern Africa, reductions in rainfall over the Limpopo and Zambezi river basins under 1.5°C and 2°C global warming could have adverse impacts on hydropower generation, irrigation, tourism, agriculture and ecosystems (Figure Box 9.5.1) (Maúre et al., 2018), although model projections of strong early summer drying trends remain uncertain (Munday and Washington, 2019).

Changes in the amplitude, timing and frequency of extreme events such as droughts and floods will continue to affect lake levels, rates of river discharge and runoff and groundwater recharge (high confidence) (Gownaris et al., 2016; Darko et al., 2019), but with disparate effects at regional, basin and sub-basin scales, and at seasonal, annual and longer timescales. The increased frequency of extreme rainfall events under climate change (Myhre et al., 2019) is projected to amplify groundwater recharge in drylands (Jasechko and Taylor, 2015; Cuthbert et al., 2019). However, declining trends in rainfall and snowfall in some areas of north Africa (Donat et al., 2014b) are projected to continue in a warming world (Seif-Ennasr et al., 2016), restricting groundwater recharge from meltwater flows, exacerbating the salinisation and depletion of groundwater (Hamed et al., 2018) and increasing the risk of reduced soil moisture (Petrova et al., 2018) in this region where groundwater abstraction is greatest (Wada et al., 2014).

Lake surface temperatures across Africa are expected to rise in tandem with increasing global warming. Lake heatwaves, periods of extreme warm lake surface water temperature, are projected to become hotter and longer (Figure 9.21), with heatwaves more than 300 days per year in many lakes for global warming of 4.2°C (Woolway et al., 2021). Lake warming is expected to have adverse consequences for aquatic biodiversity, habitats, water quality and disruption of current lake physical processes and circulation patterns (Kraemer et al., 2021).

Climate change is projected to reduce water availability and increase the extent of water scarcity (Mekonnen and Hoekstra, 2016), particularly in southern and north Africa, while other regions will be more affected by increased hydrological variability over temporally short to interannual time scales (see Section 9.6.2). African countries are considered to be particularly at risk due to their underlying vulnerabilities (IPCC, 2014b; UNESCO and UN-Water, 2020), yet the continents’ water resources are still inadequately quantified and modelled (Müller Schmied et al., 2016; Reinecke et al., 2019), constraining sustainable management practices (Cuthbert et al., 2019; Hughes, 2019).

Hydrological fluctuations are associated with drought, flood and cyclone events which have had multi-sector impacts across Africa (Siderius et al., 2021; see Chapter 4 Sections 4.3; 4.5), including: reduced crop production (D’Odorico et al., 2018), migration and displacement (Siam and Eltahir, 2017; IDMC, 2018), food insecurity and extensive livestock deaths (Nhamo et al., 2018), electricity outages (Gannon et al., 2018), increased incidence of cholera (Olago et al., 2007; Sorensen et al., 2015; Houéménou et al., 2020) and increased groundwater abstraction amplifying the risk of saline intrusion from sea level rise (Hamed et al., 2018; Ouhamdouch et al., 2019).

The literature shows significant gender-differentiated vulnerability and intersectional vulnerability to climate change impacts on water in Africa (Fleifel et al., 2019; Grasham et al., 2019; Mackinnon et al., 2019; Dickin et al., 2020; Lund Schlamovitz and Becker, 2020), although studies are generally lacking in northern Africa (Daoud, 2021). Women and girls are, in most cases, more impacted than men and boys by customary water practices, as adult females are the primary water collectors (46% in Liberia to 90% in Cote d’Ivoire), while more female than male children are associated with water collection (62% compared with 38%, respectively) (Graham et al., 2016). Women and girls face barriers toward accessing basic sanitation and hygiene resources, and 71% of studies reported a negative health outcome, reflecting a water–gender–health nexus (Pouramin et al., 2020). These differential vulnerabilities are crucial for informing adaptation, but are still relatively under-researched, more so for the urban poor than rural communities (Grasham et al., 2019; Mackinnon et al., 2019; Lund Schlamovitz and Becker, 2020).

An integrated systems and risk-based approach to the design and management of water resources at scale is generally accepted as a practical and viable way of underpinning the resilience of water systems to climate change and human pressures (Duffy, 2012; García et al., 2014). Such approaches confer multiple benefits to nature and society at scale and enhance efficiency gains through technology and management improvements, but their full implementation has not yet been realised (Weinzierl and Schilling, 2013; McDonald et al., 2014; UN Environment, 2019). Drylands are particularly singled out as ignored areas that require integrated water resource management approaches (Section 9.3.1; Stringer et al., 2021). Appropriate ecosystem-based adaptations that are applicable at scale should be identified and strongly embedded in these approaches to deliver multiple benefits while maintaining the integrity of ecosystems and biodiversity (UN Environment, 2019; see Sections 9.6.4; 9.8.5; Box 4.6). Furthermore, adaptation options are often influenced or constrained by institutions, regulation, availability, distribution, price and technologies (McCarl et al., 2016). Thus, institutional capacity to manage complex water supply systems under rapidly increasing demand and climate change stress is critical in achieving water security for African cities, particularly as cities become more dependent on alternative and distant water sources (Padowski et al., 2016).

The water–energy–food (WEF) nexus explicitly recognises the strong interdependencies of these three sectors and their high levels of exposure to climate change (Zografos et al., 2014; Dottori et al., 2018; see Box 9.5). With increasing societal demands on more variable water resources under climate change, an intensification of WEF competition and trade-offs are projected (D’Odorico et al., 2018; Dottori et al., 2018). Other interacting factors, for example, the increasing number of transnational investments in land resources can lead to localised increased competition for water resources (Messerli et al., 2014; Breu et al., 2016; Chiarelli et al., 2016). Understanding such nexus interlinkages can help characterise risks to water resource security, identify co-benefits and clarify the range of multi-sectoral actors involved in and affected by development decisions (Kyriakarakos et al., 2020). Major barriers and entry points for greater integration include coordination of horizontal policy and integration of climate change adaptation actions (England et al., 2018), capturing the scarcity values of water and energy embedded in food/energy products (Allan et al., 2015), and inclusion of community-based organisations such as water resource user associations (Villamayor-Tomas et al., 2015) and agricultural cooperatives (Kyriakarakos et al., 2020).

While natural variability in the hydrological cycle has always been considered by water resources planners and engineers (Müller Schmied et al., 2016; Muller, 2018), many countries will have to take into consideration the range of historically unprecedented extremes expected in the future. Increasingly, the provision of urban water security is dependent on the functioning of complex bulk water infrastructure systems consisting of dams, inter-basin transfers, pipelines, pump stations, water treatment plants and distribution networks (McDonald et al., 2014). Risk-based studies on the potential climate change risks for water security show that there are benefits when risks are reduced at the tails of the distribution—floods and droughts—even if there is little benefit in terms of changes in the mean (Arndt et al., 2019). When risk is taken into account in an integrated (national) bulk water infrastructure supply system, the overall impact of climate change on the average availability of water to meet current and future demands is significantly reduced (Cullis et al., 2015). Further, stemming leakages and enhancing efficiency through technology and management improvements is important in building climate-resilient water conveyance systems (UN Environment, 2019). African cities could leap-frog through the development phases to achieve a water sensitive city ideal, reaping benefits such as improved liveability, reduced flooding impacts, safe water and overall lower net energy requirements and avoid making the mistakes developed countries’ cities have made (Fisher-Jeffes et al., 2017) (Brodnik et al., 2018). However, the challenge of large proportions of the population lacking access to even basic water supply and sanitation infrastructure (Armitage et al., 2014) must be simultaneously and effectively addressed, particularly in light of other major exacerbating factors, like the COVID-19 pandemic (Section 9.11.5).

Many studies in Africa use the river basin as a unit of analysis at scale and adopt sophisticated model-based techniques to assess climate change impacts on hydrology under different climate and development scenarios, thereby presenting trade-offs between competing uses such as hydropower generation, irrigation and ecosystem requirements (Section 9.12.1; Yang and Wi, 2018; Ahmed, 2020). However, longer (multi-decadal) hydrological datasets and model improvements are required (Taye et al., 2015), and models should incorporate the quantification of the wider benefits, risks and political opportunities arising from reservoir development to better inform decision makers to achieve a higher level of (transboundary) cooperation (Digna et al., 2016; Nijsten et al., 2018). Collaboration between scientists and policymakers to address the complexity of decision making under uncertainty (Steynor et al., 2016) (Pienaar and Hughes, 2017), coupled with community involvement in participatory scenario development and participatory GIS to aid in collaborative planning that is context specific (Muhati et al., 2018; Álvarez Larrain and McCall, 2019) are powerful tools for more beneficial adaptive and resilience-building actions.

Climate change is projected to increase dependence upon groundwater withdrawals in most parts of Africa as an adaptive strategy to amplified variability in precipitation and surface water resources, highlighting the need for conjunctive surface-groundwater management and rainwater harvesting (Cobbing and Hiller, 2019; Taylor et al., 2019). Alternative water supply options such as desalination, managed aquifer recharge, stormwater harvesting and re-use (direct and indirect, potable and non-potable), all require significant amounts of energy and are complex to operate and maintain. A failure to provide a source of reliable energy and the capacity to implement, maintain and operate these systems is a significant contributor to water scarcity risks in Africa (Muller and Wright, 2016). Soft adaptation options include increasing water use efficiency, changing agricultural practices, more appropriate water pricing (Olmstead, 2014) and enhancing capacity to tackle groundwater overexploitation (Kuper et al., 2016), among others (see Section 9.10.2.4 and Chapter 4 Sections 4.6 and 4.7).

Gender is important in building resilience and adaptation pathways to global environmental change (Ravera et al., 2016). It is well-established that women, in most societies, have accumulated considerable knowledge about water resources, including location, quality and storage methods because they are primarily responsible for the management of water for household water supply, sanitation and health, and for productive uses in subsistence agriculture (UN-Water, 2006). As gender-differentiated relationships are complex, adaptation should take into account intersectional differences such as homeownership, employment and age (Harris et al., 2016), educational, infrastructural and programmatic interventions (Pouramin et al., 2020), aspects of protection and safety (Mackinnon et al., 2019), barriers to adaptation and gendered differences in the choice of adaptation measures (Mersha and Van Laerhoven, 2016), the complex power dynamics of existing social and political relations (Djoudi et al., 2016; Rao et al., 2017), and inclusion and empowerment of women in the management of environmental resources (Makina and Moyo, 2016). Incorporation of gender and water inequities into climate change adaptation would have a significant impact on achieving the SDGs (particularly 1, 3, 4, 5 and 6), while failure to incorporate gender will undermine adaptation efforts (Bunce and Ford, 2015; Fleifel et al., 2019; Pouramin et al., 2020).

Climate change is already negatively impacting crop production and slowing productivity growth in Africa (high confidence) (Iizumi et al., 2018; Ray et al., 2019; Sultan et al., 2019; Ortiz-Bobea et al., 2021). Climate change has reduced total agricultural productivity growth in Africa by 34% since 1961, more than in any other region (Ortiz-Bobea et al., 2021). Maize yields have decreased 5.8% and wheat yields 2.3%, on average, in sub-Saharan Africa due to climate change in the period 1974–2008 (Ray et al., 2019). Overall, climate change has decreased total food calories across all crops in sub-Saharan Africa by 1.4% on average compared to a no climate change counterfactual since 1970, with up to 10% reductions in Ghana and Zimbabwe (Ray et al., 2019).

Farmers perceive a wide variety of climate threats to crop production including droughts, precipitation variability, a delayed onset and overall reductions in early growing season rainfall and excess heat (Rankoana, 2016a; Elum et al., 2017; Kichamu et al., 2017; Alvar-Beltrán et al., 2020). Farmers attribute these perceived changes as a major driver of yield losses (Ayanlade and Jegede, 2016; see Section 9.4.5). Over half of surveyed farmers in west Africa perceive increases in crop pests and diseases as due to climate change as the range and seasonality of many pests and diseases change under warming (Callo-Concha, 2018). Pests and diseases contribute between 10–35% yield losses for wheat, rice, maize, potato and soybean in sub-Saharan Africa (Savary et al., 2019). Recent locust outbreaks in 2019 in east Africa have been linked to climate conditions caused in part by ocean warming (Wang et al., 2020b; see Box 5.8).

Future climate change may increase insect pest-driven losses in Africa for maize, rice and wheat. Compared to 1950–2000, losses may increase by up to 50% at 2°C of global warming (Deutsch et al., 2018). However, many challenges remain in modelling pest and disease under climate change with additional research needed expanding the range of crops and diseases studied (Newbery et al., 2016).

Agriculture in Africa is especially vulnerable to future climate change in part because 90–95% of African food production is rainfed (Adams, 2018). Maize, rice, wheat and soybean yields in tropical regions (20°S–20°N) are projected to decrease approximately 5% per degree Celsius of global warming in a multi-model ensemble (Rosenzweig et al., 2014; Franke et al., 2020). Dryland agricultural areas are especially sensitive to changes in rainfall. For example, without adaptation, substantial yield declines are projected for staple crops in north Africa. A recent meta-analysis of 56 studies indicates that, compared to 1995–2005, economic welfare in the agriculture sector in north Africa is projected to decline 5% for 2°C global warming and 20% for 3°C global warming, and in sub-Saharan Africa by 5% (2°C) and 10% (3°C) (Moore et al., 2017a), both more pessimistic than previous economic estimates.

A synthesis of projected staple crop impacts across 35 studies for nearly 1040 locations and cases shows, on average, decreases in crop yields with increasing global warming across staple crops in Africa, including when accounting for CO2 increases and adaptation measures. For example, for maize in west Africa, compared to 2005 yield levels, median projected yields decrease 9% at 1.5°C global warming and 41% at 4°C, without adaptation (Figure 9.22). However, uncertainties in projected impacts across crops and regions are driven by uncertainties in crop responses to increasing CO2 and adaptation response, especially for maize in east Africa and wheat in north Africa and east Africa (Figure 9.22; Hasegawa et al., 2021).

There is also growing evidence that climate change is likely beginning to outpace adaptation in agricultural systems in parts of Africa (Rippke et al., 2016). For example, despite the use of adjusted sowing dates and existing heat-tolerant varieties, Sudan’s domestic production share of wheat may decrease from 16.0% to 4.5–12.2% by 2050 under RCP8.5 (2.4°C global warming) (Iizumi et al., 2021).

Elevated CO2 concentrations in the atmosphere might mitigate some or all climate-driven losses (Swann et al., 2016; Durand et al., 2018), but there is considerable uncertainty around the CO2 response (Deryng et al., 2016; Toreti et al., 2020), especially when nutrients such as nitrogen and phosphorus are limiting crop growth. Additional Free-Air Carbon dioxide Enrichment (FACE) experiments are needed in the tropics, particularly on the African continent, to better understand the impacts of increased CO2 concentrations on the productivity of crops and cultivars grown in Africa under additional temperature impacts and water and nutrient limitations (Ainsworth and Long, 2021). Warming and elevated CO2 may also change the nutritional content of some crops. By 2050 under RCP8.5 (2.4°C global warming), overall wheat yields and grain protein content may decrease by 10% and 15%, respectively, in north and east Africa, and by over 15% in southern Africa (Asseng et al., 2019). See Chapter 5 for more details on CO2 impacts and uncertainties.

Few studies have attributed changes in yields of cash crops and other regionally important food crops in Africa to human-caused climate change, but recent research suggests yields of cash crops in Africa have already been impacted by climate change, in both a negative and positive manner (Falco et al., 2012; Traore et al., 2013; Ray et al., 2019). For example, between the period 1974–2008, sugarcane yields decreased on average by 3.9% and 5.1% in sub-Saharan Africa and north Africa, respectively, due to climate change, while sorghum yields increased 0.7%, and cassava yield increased 1.7% in sub-Saharan Africa and 18% in north Africa (Ray et al., 2019).

There are also limited studies assessing projected climate change impacts on important cash crops and food crops other than maize, rice and wheat (Jarvis et al., 2012; Schroth et al., 2016; Awoye et al., 2017). These studies often represent changes at specific sites in a country or assess changes in the yield and/or suitability for cultivating a specific crop across a larger geographic area. Climate change is projected to have overall positive impacts on sugarcane and Bambara nuts in southern Africa, oil palm in Nigeria and chickpea in Ethiopia (low confidence) (Figure 9.23).

Climate change is projected to reduce sorghum yields in west Africa (Figure 9.23). For example, across the west African Sahel savanna sorghum yields are projected to decline on average 2% at 1.5°C and 5% at 2°C global warming (Faye et al., 2018). For coffee and tea in eastern Africa, olives in Algeria and sunflower in Botswana and Morocco, studies indicate mostly negative impacts on production systems. For example, in Kenya, compared to 2000, optimal habitat for tea production is projected to decrease in area by 27% with yields declining 10% for global warming of 1.8–1.9°C, although yield declines may be reduced at higher levels of warming (Beringer et al., 2020; Jayasinghe and Kumar, 2020; Rigden et al., 2020). Suitable area for tea production may reduce by half in Uganda (Eitzinger et al., 2011; Läderach et al., 2013). In east Africa, the coffee-growing area is projected to shift up in elevation with suitability decreasing 10–30% between 1.5–2°C of global warming (Bunn et al., 2015; Ovalle-Rivera et al., 2015).

For all other crops, there is at least one study that finds low to highly negative impacts for one or several warming levels (Figure 9.23). Mixed results on the direction of change often occur when several contrasting sites with varying baseline climates are studied, and when a study considers the full range of climate scenarios. For example, there are mixed results on the direction of change for impacts of 1.5°C global warming on cassava, cotton, cocoa and millet in west Africa (low confidence) (Figure 9.23). In general, there is limited evidence in the direction of change, due to single studies being available for most crop-country combinations (Knox et al., 2010; Chemura et al., 2013; Asaminew et al., 2017; Bouregaa, 2019). Occasionally, two studies agree on the direction and magnitude of change, for example, for potatoes in east Africa, yields are projected to decrease by 11–17% with 3°C of warming (Fleisher et al., 2010; Tatsumi et al., 2011).

Wild-harvested foods (e.g., fruits, vegetables and insects) provide dietary diversification and for many people in Africa, wild-harvested food plants may provide a livelihood and/or nutritional safety net when other sources of food fail, such as during drought (Sunderland et al., 2013; Shumsky et al., 2014; Wunder et al., 2014; Baudron et al., 2019b). In Zimbabwe, during lean times, consumption of wild fruits increases, as does their sale to generate income for additional food expenses in poor, rural households (Mithöfer and Waibel, 2004). In Mali, Tanzania and Zambia, household surveys indicate that forest products including wild foods can play an important role in reducing household vulnerability to climate shocks by providing alternative sources of food and income during droughts and floods (Robledo et al., 2012). In the parklands of west Africa, wild trees are a significant source of wild foods and are thus a place where one might expect wild plant foods to make an important contribution to diets and nutrition (Boedecker et al., 2014; Leßmeister et al., 2015). Non-timber forest products are consumed by an estimated 43% of all households in Burkina Faso (FAO, 2019), and wild vegetables accounted for about 50% of total vegetable consumption in southeastern Burkina Faso (Mertz et al., 2001).

The focus of projected climate change impacts has been almost exclusively on agricultural production, yet climate change could have substantial impacts on the distribution and availability of wild-harvested food plants in Africa (Wessels et al., 2021). Non-cultivated species in Africa are vulnerable to current and future climate changes, with widespread changes in woody plant cover already observed (see Section 9.6.1.1). Evidence about the impacts of climate change on individual wild food species is less consistent. Communities in the Kalahari (Crate and Nuttall, 2016) and Zimbabwe (Sango and Godwell, 2015) report growing scarcity of wild foods (such as wild meat and fruit) perceived to be, at least in part, due to drought and climate change. Shea tree (Vitellaria paradoxa) nuts provide fats and oils for the diets of many rural populations in west Africa. In Burkina Faso, global warming of 3°C is projected to reduce area of suitable habitat for the shea tree by 14% (Dimobe et al., 2020). In southern Africa, 40% of native, wild-harvested food plant species are projected to decrease in geographic range extent at 1.7°C global warming with range reductions for 66% of species projected for 3.5°C (Wessels et al., 2021).

Livestock systems in Africa are already being affected by changes in climate through increased precipitation variability leading to decreasing fodder availability (Sloat et al., 2018; Stanimirova et al., 2019). More than twice as many countries in Africa have experienced increases in precipitation variability in the last century than decreases (Sloat et al., 2018). Fodder availability is also being impacted by woody plant encroachment—the increase in shrub and tree cover—which has increased by 10% on subsistence grazing lands and 20% on economically important grazing lands in south Africa in the last 60 years (Stevens et al., 2016), and is driven in part by climatic factors (see Section 9.6.1.1). Increased temperature and precipitation have contributed to the expanding range, especially in east and southern Africa, of several ixodid tick species which carry economically important livestock diseases (Nyangiwe et al., 2018).

Pastoralists in Africa perceive the climate as already changing and report more erratic and reduced rainfall, prolonged and more frequent droughts and a rise in temperature (Sanogo et al., 2017; Kimaro et al., 2018). They also report reduced milk production, increased deaths and disease outbreaks in their herds due to malnutrition and starvation resulting from the shortages in forage and water (Kimaro et al., 2018). Additional research is required to attribute precipitation variability to human-induced climate change (see Section 9.5), and to evaluate the relative contributions of climate change and management to disease vector extent.

Future climate change will have compounding impacts on livestock, including negative impacts on fodder availability and quality, availability of drinking water, direct heat stress and the prevalence of livestock diseases (Nardone et al., 2010; Rojas-Downing et al., 2017; Godde et al., 2021). Climate change is projected to negatively affect fodder availability (Briske, 2017) because overall rangeland net primary productivity (NPP) by 2050 is projected to decrease 42% under RCP4.5 (2°C global warming) and 46% under RCP8.5 (2.4°C global warming) for western sub-Saharan Africa, compared to a 2000 baseline (Boone et al., 2018). NPP is also projected to decline by 37% in southern Africa, 32% in north Africa and 5% in both east Africa and central Africa by 2050 under RCP8.5 (2.4°C global warming) (Boone et al., 2018). For example, in Zimbabwe by 2040–2070, net revenues from livestock production, compared to a 2011 survey, are projected to decline by 8–32% under RCP4.5 for 2°C and 11–43% under RCP8.5 for 2.7°C global warming due to a decline in fodder availability (Descheemaeker et al., 2018). The available literature does not comprehensively capture the economic implications of climate-related impacts on livestock production across Africa.

Fodder quality, critical for animal health and weight gain, is at risk from climate change as increases in temperature, elevated CO2 and water stress have been shown to reduce dry matter digestibility and nitrogen content for C3 grasses (Augustine et al., 2018), tropical C4 grasses (Habermann et al., 2019) and fodder crops such as Lucerne/Alfalfa (Polley et al., 2013; Thivierge et al., 2016).

Climate change is projected to threaten water availability for livestock. Droughts in Africa have become more intense, frequent and widespread in the last 50 years (Masih et al., 2014), and progressive increase in droughts between 3- and 20-fold under climate change up to 3°C of warming are projected for most of Africa (Section 9.5). In the Klela basin in Mali by 2050, groundwater recharge is projected to decline by 49% and groundwater storage by 24% under RCP8.5 (2.4°C global warming) compared to the 2006 baseline (Toure et al., 2017). Water availability for livestock during drought is a major concern for many African pastoralists including but not limited to those in Zimbabwe (Dzavo et al., 2019) and Nigeria (Ayanlade and Ojebisi, 2019). Increased livestock mortality and livestock price shocks have been associated with droughts in Africa, as well as being a potential pathway for climate-related conflict (Catley et al., 2014; see Box 9.9; Maystadt and Ecker, 2014).

Heat stress may already be the largest factor impacting livestock production in many regions in Africa (El-Tarabany et al., 2017; Pragna et al., 2018), as the combination of high temperatures and high relative humidity can be dangerous for livestock and has already decreased dairy production in Tunisia (Amamou et al., 2018). Climate change is projected to increase heat stress for all types of livestock, especially in the tropics (Figure 9.24; Lallo et al., 2018). More studies quantifying the impact of heat stress on other types of livestock production loss are needed in Africa (Rahimi et al., 2021).

Climate change will impact livestock disease prevalence primarily through changes in vector dynamics or range (Abdela and Jilo, 2016; Semenza and Suk, 2018). African Rift Valley Fever (RVF) and trypanosomiasis are positively associated with extreme climate events (droughts and ENSO) (Bett et al., 2017) and are projected to expand in range under climate change (Kimaro et al., 2017; Mweya et al., 2017). More quantitative estimates of projected risk from diseases are needed.

Marine and freshwater fisheries provide 19.3% of animal protein intake (Chan et al., 2019) and support the livelihoods of 12.3 million people (de Graaf and Garibaldi, 2015) across Africa. Estimates suggest that fish provides approximately 200 million people in Africa with their main source of animal protein and key micronutrients (Obiero et al., 2019). Although marine fisheries account for >50% of total capture fishery production (Obiero et al., 2019), 2.9 million tonnes of fish are harvested annually from inland water bodies constituting the highest per capita inland fishery production of any continent (2.56 kg per person per year) (Harrod et al., 2018a; Funge-Smith and Bennett, 2019).

Climate change already poses a significant threat to marine and freshwater fisheries and aquaculture in Africa (Blasiak et al., 2017; Harrod et al., 2018a). Severe (>30%) coral bleaching has impacted ~80% of major reef areas in the western Indian Ocean and Red Sea along Africa’s eastern coast (Hughes et al., 2018). Biological effects (e.g., changes in primary production, fish distribution) have also occurred (Hidalgo et al., 2018). Range shifts in marine fish species can exacerbate boundary conflicts among fisher communities (Penney et al., 2017; Belhabib et al., 2019). Changes in fish distribution and reductions in catch across inland fisheries are associated with climatic variability by fishing communities (Okpara et al., 2017b; Lowe et al., 2019; Muringai et al., 2019b). Floods and reduced river flow reduces fish catches (Kolding et al., 2019), which scale positively with discharge rates in rivers across Africa (McIntyre et al., 2016). Warming air and water temperatures have altered water stratification patterns in African lakes causing reductions in or redistributions of primary productivity and leading to reduced fish biomass (Section 9.6.1.3). Such changes, partially explain reduced fish catches in Lake Tanganyika (Cohen et al., 2016). In some regions, water scarcity has resulted in conflict within and among food production sectors (pastoralists, fishers and farmers) in this region (Okpara et al., 2017b). Small-scale and artisanal fisher communities are ill-equipped to adapt to climate impacts because there are few financially accessible alternative livelihoods (Belhabib et al., 2016; Ndhlovu and Saito, 2017).

At 4.3°C global warming, maximum catch potential (MCP) from marine fisheries in African Exclusive Economic Zones (EEZs) would decrease by 12–69% by the end of the 21st century relative to recent decades (1986–2005), whereas global warming of 1.6°C would limit the MCP decrease to 3–41% (Cheung William et al., 2016; IPCC, 2019c). By mid-century under 2°C global warming, MCP would decrease by 10 to >30% on the western coast of South Africa, the Horn of Africa and west Africa, indicating these regions could be at risk to declines in MCP earlier in the century than other parts of Africa (Cheung et al., 2016). Declining fish harvests due to sea temperature rise could leave 1.2–70 (median 11.1) million people in Africa vulnerable to deficiencies in iron, and up to 188 million to vitamin A and 285 million to vitamin B12 and omega-3 fatty acids by mid-century under 1.7°C global warming (Golden et al., 2016). Maire et al. (2021) assessed the nutritional vulnerabilities of African countries to climate change and overfishing, and found that the four most vulnerable countries ranked on a scale from 0 (low vulnerability) to 100 (high vulnerability) were Mozambique (87), Madagascar (76), Tanzania (61) and Sierra Leone (58). Coral reef habitat in east Africa is projected to decrease, resulting in negative impacts on demersal fish stocks and invertebrates (Hoegh-Guldberg et al., 2018). Central, west and east Africa are projected to be at the greatest nutritional risk from sea temperature rise, leading to reduced catch in coastal waters (Figure 9.25; Golden et al., 2016). In north Africa, a rise in water temperatures is expected to impact the phenology and migratory patterns of large pelagic species (e.g., bluefin tuna, Thunnus thynnus) (Hidalgo et al., 2018). Increased sea surface temperatures have been associated with increases in spring and summer upwelling intensity reducing the abundance and larval survival of small pelagic fishes and shellfish in west Africa (Bakun et al., 2015; Tiedemann et al., 2017; Atindana et al., 2020). Ocean warming, acidification and hypoxia are predicted to affect the early life history stages of several marine food species, including fish and crustaceans (Kifani et al., 2018). Climate warming is projected to impact water temperature and horizontal and vertical mixing on the southern Benguela ecosystem, with marked negative effects on the biomass of several important fishery resources by 2050 amplified under 2.5°C compared to 1.7°C global warming (Ortega-Cisneros et al., 2018).

For inland fisheries, 55–68% of commercially harvested fish species will be vulnerable to extinction under 2.5°C global warming by the end of the 21st century (2071–2100) compared to 77–97% under 4.4°C global warming (Figure 9.26). This will increase the number of countries that are at food security risk due to fishery species declines from 10 to 13 (Figure 9.26). Other recent analyses suggest that African countries with the highest inland fisheries production have low- to mid-range projected climate risk (2.4°C–2.6°C local temperature increase compared to other regions with 2.7°C–3.3°C increase by end of century) based on a 3.9°C global warming scenario (Harrod et al., 2018b). In regions where inland fishery production is derived primarily from lakes, there is a lower likelihood of reduced catch, especially where precipitation is projected to increase (e.g., African Great Lakes region) (Harrod et al., 2018b). Regions reliant on rivers and floodplains (e.g., Zambezi and Niger basins) are more likely to experience downturns in catch, as hydrological dynamics may be altered (Harrod et al., 2018b). Projections suggest that opportunistic species that do well in modified systems (Escalera-vázquez et al., 2017) and small pelagic fishes will remain important components of inland fishery food systems (Kolding et al., 2016; Gownaris et al., 2018; 2019). Climate adaptation responses that rely on freshwater resources (e.g., hydroelectric power generation, agricultural irrigation) represent threats to inland fisheries (Cowx et al., 2018; Harrod et al., 2018c), by changing flow regimes, reducing water levels, and increasing runoff of pesticides and nutrients (Harrod et al., 2018c).

For both marine and freshwater fisheries, climate-related extreme weather events and flooding may drive the loss of fishing days, cause damage and loss to fishing gear, endanger the lives of fishers and block transportation from damaged roads (Muringai et al., 2021). Fish processing via weather-dependent techniques such as sun drying may be hampered, causing post-harvest losses (Akintola and Fakoya, 2017; Chan et al., 2019).

Patterns of vulnerability and adaptive capacity are highly context dependent and vary within and among fishing communities in coastal and riparian areas (Ndhlovu and Saito, 2017; Lowe et al., 2019; D’agata et al., 2020). Interventions that integrate scientific knowledge and fishers’ local knowledge while focusing on vulnerable groups are expected to be more successful (Musinguzi et al., 2018; Muringai et al., 2019b). Infrastructure improvements (e.g., storage facilities, processing technologies, transport systems) could reduce post-harvest losses and improve food safety (Chan et al., 2019). Fisher safety can be aided by early warning of severe weather conditions (Thiery et al., 2017), enhanced through communication via mass media and mobile phones (Thiery et al., 2017; Kiwanuka-Tondo et al., 2019). Although changing fishing gears and shifting target species are important adaptation options for artisanal fishers, many have instead expanded their fishing range or increased effort (Musinguzi et al., 2015; Belhabib et al., 2016). Adapting to the impacts of climate change on marine fisheries productivity requires management reforms accounting for shifting productivity and species distributions, such as increasing marine protected areas, strengthening regional trade networks, and increasing the investment and innovation in climate-resilient aquaculture production (Golden et al., 2021). This could yield higher catch and profits in the future relative to today in 50% of African countries with marine territories under 2°C global warming and in 35% under 4.3°C global warming (Free et al., 2020). For inland fisheries, opportunities for adaptation include better integration of inland fisheries into management plans from other sectors (e.g., hydropower and irrigation) (Harrod et al., 2018c; Cowx and Ogutu-Ohwayo, 2019; McCartney et al., 2019). There is growing interest in enhancing the supply of freshwater fishery production from small water bodies and reservoirs in dryland regions of sub-Saharan Africa (Kolding et al., 2016).

The spatial distribution of climate hazards and observed impacts in terms of total people affected (displaced persons and deaths) during 2010–2020 is shown in Figure 9.27. From 2000–2019, floods and droughts accounted for 80% and 16%, respectively, of the 337 million affected persons, and a further 32% and 46%, respectively, of 46,078 deaths from natural disasters in Africa (CRED, 2019). Flooding is a major hazard across Africa (Kundzewicz et al., 2014; Douglas, 2017) and is increasing (Zevenbergen et al., 2016; Elboshy et al., 2019). An increase in extreme poverty and up to a 35% decrease in consumption has been associated with exposure to flood shocks (Azzarri and Signorelli, 2020). Sub-Saharan Africa is the only region globally that did not show decreasing rates of flood mortality since the 1990s (Tanoue et al., 2016). Economic opportunities, transportation of goods and services, and mobility and access to essential services, including health and education, are greatly hindered by flooding (Gannon et al., 2018). Severe impacts from tropical cyclone landfalls have been recorded in east and southeastern Africa (Rapolaki and Reason, 2018; Cambaza et al., 2019; Chatiza, 2019; Hope, 2019). Cyclones Idai and Kenneth in early 2019 caused flooding of districts in Malawi, Mozambique and Zimbabwe, with substantial loss and damage to infrastructure in the energy, transport, water supply, communication services, housing, health and education sectors, particularly in Mozambique (Figure 9.27; see also Cross-Chapter Box DISASTER in Chapter 4; Warren, 2019; Dube et al., 2021; Phiri et al., 2021).

Table 9.7 | Case studies of climate hazard impacts and risks to selected human settlements in Africa

From 2005–2020, flood-induced damage over Africa was estimated at over USD 4.4 billion, with eastern and western Africa being the most affected regions (EMDAT and CRED, 2020). Total damages in four west African countries (Benin, Cote d’Ivoire, Senegal and Togo) in 2017 were estimated at USD 850 million for pluvial floods and USD 555 million for fluvial floods (Croitoru et al., 2019). Unprecedented economic loss, in terms of goods and properties, estimated by the Nigerian insurance industry at USD 200 million resulted from floods in Lagos in 2011 (Adelekan, 2016). In southern Africa, the highest costs were incurred from flood losses during the period 2000–2015 (UNEP-FI, 2019b; Simpson, 2020).

Business disruptions from climate impacts have implications for deepening poverty (Adelekan and Fregene, 2015). Small and medium enterprises (SMEs) employ 60–90% of workers in many African countries and contribute 40% or more to the GDP in Ghana, Kenya, Nigeria, South Africa, Tanzania and Zimbabwe (Muriithi, 2017). The viability of businesses and economic well-being of large populations employed in SMEs is severely affected by climate hazards as reported for local wind storms in Ibadan (Adelekan, 2012), El Niño-related flooding (Nairobi), drought-induced water supply disruption (Gaborone) and power outages (Lusaka) (Gannon et al., 2018). High water demand due to high rates of urbanisation and population growth, coupled with drought, reduce groundwater levels in cities (e.g., Bouake, Harare, Tripoli, Niamey) and increase saltwater intrusion into groundwater in coastal areas, reducing water availability and water security, particularly for poorer populations not connected to municipal water networks (Aswad et al., 2019; Claon et al., 2020).

Evidence of the impact of heat waves in urban Africa in the current climate is sparse, due in part to low reporting and monitoring (Engelbrecht et al., 2015; Harrington and Otto, 2020). Knowledge is also limited on the interaction of climate change, urban growth and the urban heat island effect in Africa (Chapman et al., 2017). In north Africa, the present-day number of high heat stress nights is around 10 times larger in urban than rural areas (Fischer et al., 2012).

The highest transport infrastructure exposures are from floods (Koks et al., 2019), with potentially severe consequences for food security (Fanzo et al., 2018), communication and the economy of affected regions (high confidence) (Koks et al., 2019). Eight of the 20 countries with the highest expected annual damages to road and rail assets, relative to the country’s GDP, are located in east, west and central Africa (Koks et al., 2019). Transport impacts compound climate impacts, such as heat stress and air pollution linked to vehicle emissions in Dar es Salaam (Ndetto and Matzarakis, 2014).

African economies that rely primarily on hydropower for electricity generation are particularly sensitive to climate variability (Brooks, 2019). This sensitivity was already felt during the 2015/16 El Niño, in which Malawi, Tanzania, Zambia and Zimbabwe all experienced widespread and prolonged load shedding due to low rainfall. The impact was felt throughout the economy and reflected in reduced GDP growth in Zambia (Conway et al., 2017).

The extent of urban areas in Africa exposed to climate hazards will increase considerably and cities will be hotspots of climate risks, which could amplify pre-existing stresses related to poverty, exclusion and governance (high confidence) (IPCC, 2018b).

Climate change poses an increased risk to energy security for human settlements in Africa (high confidence). With burgeoning urban populations and growing economies, sub-Saharan Africa’s electricity needs are growing. The International Energy Agency (IEA) projects total generation capacity in Africa must grow 2.5 times from 244 GW in 2018 to 614 GW by 2040 (IEA, 2019). African nations plan to add significant generation capacity from natural gas, hydropower, wind and solar power. Each of these technologies is associated to a varying degree with climate risk.

The long lifespan of hydropower dams exposes them to decades of climatic change risk. There is a wide range of uncertainty around the future climate of Africa’s major river basins, but in several basins, there is the likelihood of increased rainfall variability and a drier climate (see Box 9.5). In countries that rely primarily on hydropower, climate change could have considerable impacts on electricity prices and as a result, consumers’ expenditure (Sridharan et al., 2019). With increasing societal demands on limited water resources and future climate change, it is expected that there will be an intensification of WEF competition and trade-offs (high confidence) (Section 9.7; Box 9.5).

Climate change and SLR will result in high economic costs for road infrastructure in sub-Saharan Africa (medium confidence) (Chinowsky et al., 2015). Across Africa as a whole, potential cumulative costs estimates through 2100 range from USD 183.6 billion (with adaptation) to USD 248.3 billion (no adaptation) to repair and maintain existing roads damaged by temperature and precipitation changes directly related to projected climate change (see Figure 9.30) (Chinowsky et al., 2013). Climate-related road damage and associated repairs will be a significant financial burden to countries, but to varying degrees according to flood risk, existing road asset liability, topography and rural connectivity, among other factors (Chinowsky et al., 2015; Cervigni et al., 2017; Koks et al., 2019). For example, Mozambique is projected to face estimated annual average costs of USD 123 million for maintaining and repairing roads damaged directly by precipitation and temperature changes from climate change through 2050 in a median climate change scenario for a policy that does not consider climate impacts during road design and construction (Chinowsky et al., 2015). Risk of river flooding to bridges in Mozambique under current conditions is estimated to be USD 200 million, equal to 1.5% of its GDP per year, and could rise to USD 400 million per year in the worst-case climate change scenario by 2050 (Schweikert et al., 2015).

Autonomous responses to climate impacts in 40 African cities show that excess rainfall is the primary climate driver of adaptation, followed by multi-hazard impacts, with 72% of responses focused on excess rainfall (Hunter et al., 2020). Innovation for adaptation in areas such as home design, social networks, organisations and infrastructure, is evident (Swanepoel and Sauka, 2019). Social learning platforms also increase communities’ adaptive capacities and resilience to risk (Thorn et al., 2015).

There is limited evidence of successful, proactively planned climate change adaptation in African cities (Simon and Leck, 2015), particularly for those countries highly vulnerable to climate change (Ford et al., 2014). Planned adaptation initiatives in African cities since 2006 have been predominantly determined at the national level with negligible participation of lower levels of government (Ford et al., 2014). Adaptation action directed at vulnerable populations is also rare (Ford et al., 2014). There are emerging examples of cities planned climate adaptation measures, such as those advanced by Durban (Roberts, 2010), Cape Town (Taylor et al., 2016) and Lagos (Adelekan, 2016). There are also examples of community-led projects such as those in Maputo (Broto et al., 2015), which have seen meaningful help from a range of policy networks, dialogue forums and urban learning labs (Pasquini and Cowling, 2014; Shackleton et al., 2015). These researched cities can be lighthouses for wider exchange and the basis for a deeper synthesis of evidence (Lindley et al., 2019). However, planned adaptation progress is slow, especially in west and central Africa (Tiepolo, 2014).

Ecosystem-based approaches are also being deployed in mitigating and adapting to climate change, with demonstrated long-term health, ecological and social co-benefits (Section 9.6.4; Swanepoel and Sauka, 2019). The cost–benefit analysis of nature-based solutions, compared to purely grey infrastructure initiatives, is discussed in Chapter 6 (Section 6.3.3). Nature-based solutions can also lengthen the life of existing built infrastructure (du Toit et al., 2018). Since 2014, an increasing number of EbA projects involving the restoration of mangrove, wetland and riparian ecosystems have been initiated across Africa, a majority of which address water-related climate risks (Table 9.9).

Table 9.9 | Examples of ecosystem-based adaptations to climate impacts in African cities.

For green infrastructure to be successful, however, sustainable landscapes and regions require both stewardship and management at multiple levels of governance and social scales (Brink et al., 2016).

Currently, planned climate change adaptation to coastal hazards in Africa’s large coastal cities has mainly been achieved through expensive coastal engineering efforts such as sea walls, revetments, breakwaters, spillways, dikes and groynes. Examples are found in west Africa (Adelekan, 2016; Alves et al., 2020). Beach nourishment efforts have also been undertaken in Egypt, Banjul and Lagos (Frihy et al., 2016; Alves et al., 2020). However, the use of vegetated coastal ecosystems presents greater opportunities for African cities because of the lower costs (Duarte et al., 2013).

Most (>80%) of Africa’s large coastal cities have no adaptation policies and, where available, these are mostly, except for South Africa, dominated by national plans (Olazabal et al., 2019). Coastal adaptation actions minimally consider socioeconomic projections and are not at all aligned with future climate scenarios and risks, which is highly limiting for adaptation planning (Olazabal et al., 2019).

Africa’s smaller towns and cities have received far less scholarly and policy development attention for adaptation (Clapp and Pillay, 2017; White and Wahba, 2019). Smaller towns also have less ability to partner effectively with private entities for adaptation initiatives (Wisner et al., 2015). Political will to address climate change and information flows between key stakeholders, professional and political decision makers may be easier to establish in smaller cities than in the megacity context (Wisner et al., 2015).

Exposure and vulnerability are particularly acute in informal areas, making coordinated adaptation challenging. Yet, there is growing recognition of the potential for bottom-up adaptation that embraces informality in order to more effectively reduce risk (Figure 9.31; Taylor et al., 2021a). This can provide an opportunity for change towards more risk-sensitive urban development and transformative climate adaptation (Leck et al., 2018). Addressing social vulnerability is particularly important for ensuring the resilience of populations at risk. Improved monitoring, modelling and communication of climate risks is needed to reduce the impacts of climate hazards (Tramblay et al., 2020; Cole et al., 2021a).

Higher costs will be incurred to maintain and repair damages caused to existing roads as a result of climate change for countries with no adaptation policy for transport infrastructure (very high confidence) (Chinowsky et al., 2013; Cervigni et al., 2017; Koks et al., 2019). Countries with a greater percentage of unpaved roads will, however, incur higher economic costs through adaptation policy when compared to no adaptation policy (Cervigni et al., 2017).

Adaptation measures in the transport sector have focused on the climate resilience of road infrastructure. Modelling suggests that proactive adaptation of road designs to account for temperature increases is a ‘no regret’ option in all cases, but accounting for precipitation increases should be assessed on a case-by-case basis (medium confidence) (Cervigni et al., 2017). African governments will need climate adaptation financing options to meet the higher capital requirements of resilient road infrastructure interventions (Hearn, 2016).

Under the Nationally Appropriate Mitigation Action programme, investments in public transport and transit-oriented development are highlighted as desired mitigation–adaptation interventions within cities of South Africa, Ethiopia and Burkina Faso (UNFCCC, 2020). These interventions simultaneously reduce the vulnerability of low-income residents to climate shocks, prevent lock-ins into carbon-intensive development pathways and reduce poverty (high confidence) (Hallegatte et al., 2016; Rozenberg et al., 2019). The combined mitigation–adaptation interventions in the land use transport systems of African cities are also expected to have sufficient short-term co-benefits (reducing air pollution, congestion and traffic fatalities) to be ‘no regret’ investments (very high confidence) (Hallegatte et al., 2016; Rozenberg et al., 2019). Only eight African countries have transport-specific adaptation measures in their NDCs (Nwamarah, 2018). Five African countries have submitted NAPs (Table 9.10).

Table 9.10 | Transport sector references in the National Adaptation Plans (NAPs) of five African countries. Source: Government of Burkina Faso (2015); Government of Cameroon (2015); Government of Togo (2016); Government of Kenya (2017); Government of Ethiopia (2019).

Most electricity infrastructure in Africa has been designed to account for historical climatic patterns. Failure to consider future climate scenarios in power system planning increases the climate risk facing infrastructure and supplies. Yet, energy demand for cooling over Africa, for example, is expected to increase, with a potential increase in heat stress, population growth and rapid urbanisation to 1.2% of total final energy demand by 2100 compared to 0.4% in 2005 (Parkes et al., 2019). Integrated energy system costs from increased demand for cooling to mitigate heat stress are projected to accumulate from 2005 to USD 51.3 billion by 2035 at 2°C and to USD 486.5 billion by 2076 at 4°C global warming (Parkes et al., 2019).

For hydropower, adaptations to different climate conditions can be made at the level of the power plant, turbine size and reservoir storage capacities, and can be adjusted to projected hydrological patterns (Lempert et al., 2015). At the river basin level, integrated water resource management practices can be implemented across sectors that compete for the same water resources (Howells et al., 2013). At the power system level, the energy mix and the protocol through which different power plants are dispatched can be adapted to different climate scenarios (Spalding-Fecher et al., 2017; Sridharan et al., 2019).

Given the uncertainty around future hydroclimate conditions, hydropower development decisions carry risk of ‘regrets’ (that is, damages or missed opportunities) when a different climate than was expected materialises. ‘Robust adaptation’ refers to an adaptation strategy that balances risks across different climate scenarios (Cross-Chapter Box DEEP in Chapter 17; Cervigni et al., 2015). Development bank lending principles require consideration of the regional picture and interactions with other developments along a river when they determine the social and environmental impacts of the proposed hydropower project. However, these principles often do not explicitly consider climate change, so the risk of recurring drought-induced hydropower shortages could be missed (Box 9.5).

Lastly, given the degree to which hydropower competes with other sectors and ecosystems for the same water resources, it is critical that hydropower planning and adaptation does not occur in isolation. As discussed in Section 9.7, it must be part of an integrated water management system that balances the needs of different water-reliant sectors with other societal and ecological demands under increasingly variable climate and hydrological conditions (Section 9.7.3).

During extreme conditions, for example, Cyclone Kenneth (Codjoe et al., 2020) and El Niño 2015–2016 (WHO, 2016; Pozniak et al., 2020), direct physical injury, loss of life, destruction of property and population displacement can occur. Flooding and landslides are common after extreme rainfall and are the most frequently described impact of climate variability in Africa’s cities currently, with residents of poorly serviced or informal settlements most vulnerable (Hunter et al., 2020). Post-traumatic stress disorders in affected individuals are common, including in children (Rother, 2020). In rural areas, the resulting damage to health facilities, access routes and transport services can severely compromise health service delivery (WHO, 2016). The effects of extreme weather on urban health infrastructure depends on the characteristics, location and adaptive capacity of cities (see Section 9.9.4).

Links between climate change and the environmental risk factors for non-communicable diseases (NCDs) may be direct (e.g., extreme heat exposure in people with cardiovascular disease) or indirect, such as via the global agriculture and food industry (Landrigan et al., 2018). These effects are largely unreported for Africa (Amegah et al., 2016), where the burden of many NCDs is growing rapidly with increasing urbanisation and pollution (Rother, 2020).

Many urban poor populations have unhealthy dietary practices, which present major risks for obesity, type II diabetes and hypertension. Paradoxically, despite growing levels of undernutrition, the incidence of overweight and obesity continues to rise in Africa, particularly in children under 5 years from the northern and southern parts of the continent (FAO and ECA, 2018). Diabetes is increasingly prevalent and outcomes may worsen if climate change undermines health infrastructure and the range of available foods (Keeling et al., 2012; Kula et al., 2013; Chersich and Wright, 2019).

The relationship between cancer and climate change is complex and indirect. Changing temperature and humidity may alter the distribution of aflatoxin-producing fungi, contaminating food (grains, maize) and causing cancer (see Box 5.9 in Chapter 5; Sserumaga et al., 2020; Valencia-Quintana et al., 2020). Severe storms and flooding may disrupt wastewater treatment or disposal, potentially contaminating drinking water with carcinogenic substances.

Areas with low service provision (e.g., informal settlements in Africa) suffer from increased infestations of pests such as flies, cockroaches, rats, bedbugs and lice, which may be controlled by chemical pesticides (Rother et al., 2020) and may become more prevalent with a changing climate (Mafongoya et al., 2019). Inappropriate pesticide use and disposal cause endocrine disruption and increased incidences of some cancers (Rother et al., 2020).

Links between air quality and climate change are complex (Smith et al., 2014; Szopa et al., 2021). Increases in particulate matter concentrations are driven more by vehicle emissions, solid waste, biomass burning and development (Abera et al., 2021) than by climate change, and these factors vary widely across regions of the continent (West et al., 2013). Women and children who are exposed to high particulate matter concentrations when cooking indoors and HIV-infected people are more vulnerable to the health impacts of air pollution (Abera et al., 2021). Information on the direction of change of air quality in different African regions attributable to climate change are contradictory (Westervelt et al., 2016; Silva et al., 2017). Additionally, much uncertainty remains about interactions between air quality and climate change and relative impacts of different modes of development and climate change on pollutants. However, increasing temperatures combined with a reduction in rainfall are likely to increase particulate matter concentrations (Abera et al., 2021), particularly in north Africa (Westervelt et al., 2016; Silva et al., 2017).

Nevertheless, continued dependence on fossil-fuelled power plants will result in tens of thousands of avoidable deaths due to air pollution by 2030 (Marais and Wiedinmyer, 2016), and accelerate climate change. Actions to reduce air pollution can both mitigate climate change and have major co-benefits for health (West et al., 2013; Rao et al., 2016; Markandya et al., 2018; Rauner et al., 2020a; Rauner et al., 2020b) see also AR6 WGIII, Chapters 3, 4, 8 and 10). Investing in renewable energy resources rather than reliance on the combustion of fossil fuels would mark an important step forward for African population health (Marais et al., 2019). This is especially important in South Africa which emits approximately half the total carbon emissions for Africa, ranking 12th in the world for carbon emissions (Mohsin et al., 2019).

Dust events in west Africa have severe health impacts (cardiorespiratory and infectious diseases, including meningitis) (Ayanlade et al., 2020) given the proximity of the Sahara, which produces about half of the yearly global mineral dust (de Longueville et al., 2013). Wildfires are projected to become the main source of particulate matter in west, central and southern Africa under both the lowest and highest future emissions scenarios, whereas, under intermediate scenarios (i.e., SSP3/RCP4.5), anthropogenic sources of particulate matter are projected to exceed that produced by wildfires (Knorr et al., 2017).