1 Introduction

Everything is connected in today’s world, especially with increasing effects of climate change. For instance, the mechanisms involved in pursuing sustainable development (SD) is itself as a unit delicately sustained by interactions that may be threatened by the end products of developments. To this end, population growth, rapid urbanization, environmental degradation, climate change and food security are key challenges. In Africa, demography-related issues are prominent features in pursuit of SD. When the world population peaks at 10 billion by the year 2050, Africans will be a significant contributor due to present fertility rate, higher life expectancy, and significant disparities in old versus young people in Nigeria, Democratic Republic of Congo, Ethiopia, United Republic of Tanzania, Ugandaas well as Angola, Burundi, Malawi, Mali, Niger, Somalia, and Zambia (UNDESA 2017). Moreover, thirty-one countries in sub-Saharan Africa (SSA)is projected to at least double their populations by 2050 (UN 2011). This is a blessing turned curse, as population growth will compound issues of SD in a continent already polarized by poverty, war, diseases, inefficient, and insufficient infrastructural systems. Unsustainable options remain the attractive approach to alleviate these challenges. However, an analysis of SD challenges and opportunities through sufficient knowledge about the size, composition, and distribution of population, rate of urbanization, per capita income status, and food production systems may facilitate sustainable decision-making (Angel et al. 2011; Mutunga et al. 2012).

Africa is urbanizing quickly, with cities and towns growing at an annual rate of 4% while economic growth is 5% (Bafana 2016; Henderson et al. 2013, 2017). Although a large proportion of Africans are still rural residents; urban growth rates are among the most rapid in the world and are almost twice the global average (UNPD 2001). Currently, over 40% of Africa’s more than one billion residents reside in urban centres but by 2050, 60% of the estimated 2.3 billion people will be urban dwellers (UN 2011; Arouri et al. 2014). Angel et al. (2011) reported that in the last decades, cities have more than doubled their population growth rates. For instance, Ghana’s urban population grew from 4 million to 14 million in 30 years while Ouagadougou (Burkina Faso) is predicted to increase from 1.9 to 3.4 million in the next decade, which depicts a change rather than continuity due to migration (Lindén et al. 2006; Klopp and Paller 2015; Owusu and Oteng-Ababio 2015). This is an SD challenge because Africa has the lowest amount of urban centres but greater population densities. Hence, the exponential growth of urbanization, which is perceived as a development index will increase land use competition for food, energy consumption, environmental management issues, and the effects of climate change.

African capital cities are the main urban centres and these are rife with unsustainable development issues, overpopulated, and not properly planned to suit present and future needs. The development of different aspects of cities in Africa follows the set direction of their colonial past. For instance, Francophone cities are spatially compact and less fragmented whereas Anglophone cities have less intense land use and more irregular layouts (Baruah et al. 2017). Moreover, in contrast with the rest of the world, Africa’s urbanization is not entirely associated with economic growth (Arouri et al. 2014). Although it continues to attract the poor, there is no commensurate investment to empower them. African countries have so many government divisions with mandates to promote economic and ecological development but these are only reminiscence of the failed systems. However, due to rapid population growth, African nations are at a critical point in their development (Hogarth et al. 2015). Hence, Africa seems to be doing better economically than ecologically as some of the world’s fastest-growing economies are in the continent. However, this economic development is encouraging urbanization and the associated challenges including increased pollution through greenhouse gases (GHG), traffic congestion, displacement, environmental deterioration, settlements on marginal lands, and degradation of basic services. Africa does not have the opportunity to pursue unsustainable development due to increased consciousness about climate change effects.

No singular index can power SD. For instance, significant economic development may be quickly overshadowed when their destructive products persist in the environment and cause climate change. Thus, it is necessary to adopt a diverse economic and ecologic approach to promote SD in order to address the entire interacting indices. More so, exploiting natural resources may lead to economic growth and expansion of existing cities to absolve the new workforce. In the end, environmental quality may depreciate from increased GHG emissions.

The objective of this chapter is to highlight how urbanization and climate change are dictating the pace of SD in Africa. The chapter considers the effects of population and economic growth as well as how ecological issues drive urbanization and climate change in Africa. This chapter is divided into two sections. The state of SD and climate change impactsin Africa is the focus of the first part while the second part makes a case for addressing the various interacting indices in the SD discourse. Ecological security remains a topical challenge in Africa. However, the current rate of urbanization may increase urban food security challenges, and in a bid to satisfy this necessity; environmental resources may be unsustainably exploited. The biggest practical challenge in Africa is how development can help raise the living standards and reduce poverty without degrading the ecosystems on which life depends (Turok and McGranahan 2013).

2 Impacts of Climate Change: An African Perspective

Africa (with GHG emissions of 3.8%) is the least contributor to global warming in both absolute and per capita terms but the most vulnerable to climate change effects (Sy 2016). According to the UNFCCC (2006) report, Africa is already experiencing temperatureincreases of approximately 0.7 ℃, which has caused a decrease in food production, increased floodingand inundation of coastal zones and deltas, the spread of diseases, changes in natural ecosystems, and biodiversity decline. Africa’s harmful emissions are mostly from deforestation and the use of fossil fuel for electricity, transportation, and diverse manufacturing processes (see Fig. 1, USDoE 2012). Nonetheless, Africa’s CO2 emissions are low and despite recent increases due to urban consumption patterns, it is still less than the emissions for some single nations including Mainland China, the USA, India, Russia, and Japan (see Fig. 1, USDoE 2012; Boden et al. 2011; Katircioglu and Katircioglu 2017). A small number of nations are largely responsible for 84% of African emissions from fossil fuels, particularly South Africa, Egypt, Algeria, Nigeria, Libya, and Morocco (Boden et al. 2011).

Fig. 1
Two graphs plot million metric tons of carbon versus year. Graph 1 has 6 fluctuating curves that increase. Graph 2 has an increasing curve with fluctuations.

(Source Adapted from USDoE [2012])

Total fossil fuel CO2 emission from Africa (i) and per capita CO2 emission estimates from Africa (ii)

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Urban air pollution is a major environmental risk that may be used as a marker of SD (WHO 2016). Air pollution in Africa is primarily in the form of suspended particulate matter (PM), which often emanate from industrial and non-industrial activities (Orubu and Omotor 2011). Africa lacks a reliable system for measuring, reporting and verification (MRV) of air pollution. Hence, according to Petkova et al. (2013), routine PM MRV does not exist in most African cities and only a few studies have reported annual mean levels of PM10 (coarse PM) and PM2.5 (fine PM). Recently, WHO (2016) reported that Africans breathe much higher levels of air pollutants that those living in other parts of the world. The report suggests that Onitsha (Southeast Nigeria) is the most polluted city in the world while two other Nigerian cities (Aba and Kaduna) are in the top ten. To bridge this air pollution MRV gap, Africa should strengthen existing capacities and structures to monitor air quality using standardized and reliable methods.

Environmental conditions are worse in the cities than in the rural areas of Africa (Nsiah-Gyabaah 2003). In most cases, there is insufficient information to make local scale predictions of the effects of environmental change but studies of observed temperaturesuggest a warming trend that is consistent over the continent, but not uniform (Parnell and Walawege 2011). Hence, the consensus to limit global warming to 1.5 ℃ to avert catastrophic climate change (IPCC2013). The global approach to mitigate climate change through carbon capture and storage technology is gaining popularity because of its potential to reduce carbon emission from point sources, thereby preventing it from getting to the atmosphere (Khoo et al. 2011; CCS Roadmap Storage Strategy 2016; Yoro and Sekoai 2016). Despite its popularity, Africa is yet to practically adopt the technology. As a result, the atmospheric concentration of anthropogenic gases, such as CO2, has increased substantially over the past few decades (Yoro and Sekoai 2016). Moreover, the relative carbon footprint (which is the ratio of a city’s carbon footprint over its country’s national average) proposed by Da Schio and Brekke (2013) to measure whether cities amplify or reduce anthropogenic impacts on the environment. Due to the absence of data, the only African country considered was South Africa, which highlighted the importance of sustainable MRV, specific policies, and relevant governance dynamics in determining the relative performance of cities to climate change. The lack of these systems have led to a greater impact of climate change through a decline in agricultural outputs, higher food prices and other socio-economic challenges that threatens SD (UNFCCC2006; Pegels 2010; Yoro and Sekoai 2016; Sy 2016).

According to Mutunga et al. (2012), there is a strong correlation between urban population growth and climate change, and their role in SD, even though they are often addressed separately at policy and programme levels. Climate change exhibit the characteristic “pull” and “push” effects in Africa. As described by Aroura et al., it is the main driver of recent migration in Africa due to the prospects of better urban jobs and economic opportunities (pull) as well as the low rural agricultural productivity and civil wars (push). Rural agriculture accounts for about 40% of Africa’s GDP but 80% remain dependent on low-yielding, rain-fed agriculture (Sy 2016). This relatively inefficient agricultural system is compounded by the negative impacts of climate change. The number of climate change refugee is increasing due to factors such as drought, famine, andflooding, which have affected their means of livelihood. Climate change continues to alter the frequency and duration of rainfall and sunlight. New varieties of pest and diseases have also evolved and pollinators’ life cycle is no longer predictable. The people whose livelihoods are most vulnerable to climate change are the rural and urban poor (Satterthwaite 2008). Temperatureand rainfall anomalies cause a minimum of 128,000 people to be displaced in Africa every year, which may become 11.8 million people by the end of the twenty-first century (Marchiori et al. 2012). Human responses such as urban “push” migration are the inevitable outcome of climate change including reduced productivity and migrations. As a result, World Bank (2009) suggested that the slow-growing, rapidly urbanizing countries in Africa are experiencing “push” rather than “pull” driven urbanization as a result of agricultural stress caused by the climate change. This gives a new dimension to ongoing environmental change, resource exploitation trend and food production crisis within the continent. As opined by Yan et al. (2016), this “push” may compound urban climate variability through increasing local surface air temperaturesand weakening of wind speed, temporal-spatial pattern of extreme precipitation, heat waves (anthropogenic heat), alteration of fauna and flora adaptation strategies, and land-use changes beyond the carrying capacity. Already in East Africa, high population growth coincides with regions of high urban heat island potential (McCarthy et al. 2010). As is the case in China, rapid urbanization and continuous economic growth led to a steady increase in resource consumption and SD crisis (Bao and Chen 2015).

In Africa, climate change can increase flooding risks through higher sea levels and storm surges, heavier and prolonged rainfall and from changes that increase river flows (Satterthwaite 2008). Sea-level rise is expected to cause a variety of impacts in densely populated African cities located within or around low-elevation coastal zones like Mombasa (Kenya), Port Harcourt (Nigeria) and Saint Louis (Senegal) (Dodman 2009). At any level of geographical aggregation, the total GHG emission is proportional to income per capita multiplied by population and GHG emissions per dollar of income and the marginal damage caused by GHG production (Kahn 2009). This is worrisome considering that Africa’s urban population and per capita income is growing in rates not proportional to ecological and food security. As a result, Satterthwaite (2008) suggested that hitherto unrelated indices would be brought together by the impacts of climate change-related events. Hence, climate change is capable of negatively affecting the social and cultural structures of African cities by worsening inequality, poverty, and mandatory lifestyle changes. Furthermore, changes in urban land-use regime remains a major contributor to climate change by affecting the physical, chemical, and biological characters. The biogeochemical impact of urban land-use change on the climate produces changing atmospheric concentrations of GHGs (Yao et al. 2015). Despite the region’s relatively low per capita levels of GHG emissions, the growing risk of catastrophic global climate change means that all countries must move away from high-emission models of economic growth (Hogarth et al. 2015). Africa’s dependence on agriculture also characterizes their high vulnerabilityalthough it may be mitigated through improved seeds and increased irrigation (Henderson et al. 2017). Therefore, a proactive and reactive management approach is required if Africa is to adapt to climate change (Palmer et al. 2008). Specifically, a more aggressive approach is required to reduce pollutant by innovating away from fossil sources to meet their energy needs and establishing vegetative buffers in urban centres as urbanization combined with climate change will be more environmentally costly than either impact alone (Nelson et al. 2009; Deressa 2016).

Seventy percent of major global droughts in 2012 occurred in Africa while in 2013, heavy rains led to flooding in significant parts of Africa (Deressa 2016). Furthermore, according to IPCC (2007), Mt. Kilimanjaro (in Tanzania) has lost 80% most of its ice cover while the remaining cover is likely to disappear between 2015 and 2020 due to climate variability, fire, human modifications, and vegetation changes. The UN-REDD + Programme (2009) also reported large-scale deforestation and forest degradation because of agricultural expansion, conversion to pasture land, infrastructural development, and logging. At this rate of change, extreme heat events, aridity, and changes in rainfall patterns will increase especially in East and Southern Africa (Serdeczny et al. 2016). Already there are prolonged and intensified droughts in Eastern Africa; unprecedented floods in Western Africa; depletion of rainforests in equatorial Africa; and an increase in ocean acidity around Africa’s southern coast and together they undermine Africa’s ability to grow and develop sustainably (Lisk 2009). These challenges call for increased ecological literacy, a widened ethical responsibility, investigations into a range of psychological and social adaptations as well as the allocation of resources and training to improve competencies in addressing climate change-related impacts (Doherty and Clayton 2011). Collective effort to address climate change championed by the African Union and other international and regional organizations has not been entirely successful. An example is the Nairobi Declaration, which sought to establish a comprehensiveframework for climate change programmes (Hogarth et al. 2015; Scholtz and Verschuuren 2015). The absence of consistent monitoring and review of climate change MRV does not match the dynamic nature of climate change challenges.

3 Issues of Sustainable Development in Africa

The concept of development is as dynamic as its definition. SD is often associated with ecology, economics, and cultural (social) processes or dimensions (Fig. 2, Leat et al. 2011). Hence, issues pertaining to SD also operate at the interface of these issues. A meaningful SD should encompass meeting the present and future ecological, economic and cultural needs of the society without compromising the means and capacity of requisite resources.

Fig. 2
A Venn diagram presents economic, environmental, and social dimensions. Sustainable development is the intersection of the three dimensions.

(Source Leat et al. [2011])

Dimensions of sustainable development

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Contemporary challenges impeding SD in Africa include but are not limited to urbanization, tourism, agriculture, pollution, transportation, natural resources, water-related issues, eutrophication, desertification, soil, and biodiversity. To conceptualize the dimensionality of SD challenges, it is necessary to examine the factors that predispose SSA to serious anthropogenic environmental degradation along with a suggestive comparison with those solely caused by nature (Mabogunje 1995). The fear of a global resource scarcity propelled the first wave of twentieth-century SD (Bizikova et al. 2013). The composite terms of SD when considered separately have a unique meaning related to human advances and resource use but together they reflect an approach to attain both independent goals. Therefore, SD is a paradigm shift from the economic growth hinged on depletion of resources and environmental degradation to address a changing climate, loss of biodiversity, abject poverty, and environmental degradation (Imam-Tamim 2012; Ojo and Oluwatayo 2016).

The doctrines of SD are mostly derived from economics but have in recent decades incorporated environmental and other considerations and are still evolving. SD strives to address the efficient use and distribution of shared resource so that future generations can also benefit. To ensure environmental sustainability, the natural capital must be used respectfully to prevent irreversible damages. This is necessary since the environment plays the role of source and sinks (Basiago 1999).

African governments have implemented several SD policies but deep scepticism persists about their results (Ahenkan and Osei-Kojo 2014). The Sustainable Development Goals (SDGs) are the new paradigm on which recent SD efforts are driven and in spite of their huge promises, are yet to produce expected economic, social, and environmental results. However, there has been a collective realization that meaningful development requires an integrated approach including in the measurement of indices such as per capita income, economic growth and development, inequality, poverty, population growth versus resource use, ecological productivity and status, etc. At the heart of pursuing SDGs in Africa is the desire to expand existing infrastructures, build resilient public institutions, reduce poverty, develop new technologies, create more employment, combat diseases, develop and implement climate change adaptation, and mitigation strategies (Ahenkan and Osei-Kojo 2014). SSA is endowed with a diverse and rich environment that is central to her growth and transformation but there seems to be no end in sight to the cycle of poor environmental management (Omisore 2018). However, commendable economic performance and a record of aid reception have created neither sufficient jobs nor SD (Norton 2012).

Mabogunje (1995) summarized the factors hampering SD in Africa as a poor development strategy that has wrought serious environmental havoc without improving the standard of living despite a substantial decline in natural resources. This trend needs to be reversed by considering the whole system as a unit while addressing topical issues using a comprehensive and integrated approach. After all, the environment does not exist as a sphere separate from human actions, ambitions, and needs, hence, SD is complex, multidimensional and dynamic (Imam-Tamim 2012; Oladeji 2014). Africa’s urbanization is occurring at lower levels of income and with far less investment in infrastructure to accommodate a larger population (Freire et al. 2014). Furthermore, the poor quality or unavailability of data continues to hinder the quality of analysis of African urbanization and SD that is required for planning and policy formulation (Simkins 2013; Henderson et al. 2013, 2017). As a result, efforts to address SD challenges are handicapped by a real failure to understand their nature and possible remedies (Mabogunje 1995). The carrying capacity of the environment and resource exploitation are rarely considered in SSA. Hence, it may be hypothesized that increase in urbanization is not presently proportional to SD but proportional to resource exploitation and environmental degradation because of the rise in multi-complex threats associated with urbanization like land use and conversion for development, mining, etc.

Recent development has made it essential to look at SD as an envelope of interacting principles consisting of futuristic, environmental, public participation, and equity considerations (Iwaro and Mwasha 2013). These considerations will require efficiency in resource use and recycling processes because of the definitive role of public participation to SD as well as for the preservation of the ecosystem, energy conservation and resources conservation for future generations. These considerations could act as an objective response mechanism to SD threats in Africa. Considering that, environmental disasters threaten human and ecological security while inducing migration and competition for basic resources, with potentially negative consequences for political stability and conflict resolution (Lisk 2009). Specifically, in Zambia, rainfall variability will lower agricultural growth by 1% each year and cost the country US$4.3 billion in GDP over 10 years (AFDB 2013). Climate change poses a significant and unique challenge to Africa’s SD because of its agro-dependent economy, which is ill-prepared to adapt to or mitigate the powerful effects (Deressa 2016).

4 Contextualizing Ecology and Food Security in Africa’s Sustainable Development

High food prices and low income especially in urban centres have increased the prevalence of food insecurity and malnutrition in African countries (UN 2009; Kabasa and Sage 2009). These issues are linked to a broad environment and economic-related issues. According to ECA (2004), environmental security is inextricably linked with human security, so much so that it is defined by the capacity of humans to live harmoniously with nature and to maintain a sustainable environment. However, the process of urbanization heightens general concern on socio-ecological factors like land, water availability/drought, gender, erosion, fertilizer, pollution, habitat destruction, diseases, infrastructures, national integrity/security, germplasm conservation, religious, micro-climatic conditions (agronomic perspectives), government (politics), etc., which interact to influence SD. Therefore, any strategy that focuses only on one of these interconnections risks serious unsustainable consequences. Thus, a systematic approach and a quest for integrated solutions to guide SD decision-making are paramount (Klümper and Theesfeld 2017).

There are different ways in which environmental change generally, and food production specifically is linked as in natural resource use. According to Norton (2012), there are three key features of natural resource use, which are:

  1. 1.

    Greater competition among users (people and countries) and among uses (sectors) for a limited pool of resources,

  2. 2.

    Greater interconnections between the demographic and socio-economic drivers of production and consumption, and

  3. 3.

    The possibilities of absolute scarcity, or irrevocable deterioration of ecosystem functions.

Recent urbanization trends in Africa have affected the facets of food security, i.e. food availability, accessibility, utilization, and stability of food systems. As a result, Africa urgently needs to increase food production to protect these facets challenged by increasing population and degraded environment. Obioha (2009) posited that the suitability of the environment to act as a support system depends on the stability of the dynamic dependent systems.

Ecological security may have nature-centric (i.e. viewing nature as an entity to maintain optimal associations among organisms), human-centric (i.e. humans as nature’s dominant user and controller human-centric) or eclectic approach (Cherry 1995). Generally, an ecological security discourse should orient towards the resilience of ecosystems themselves, which enhances the protection of the most vulnerable across time, space and organisms (McDonald 2012). The nature-centric approach may encourage conflict scenarios stemming from the need to exploit environmental capital to keep up with the pace of human development and the need to be sustainable (Omole and Ndambuki 2014). In urban centres, a shift towards improving ecological security might be difficult to imagine but could be necessitated by a number of factors including the difficulty to justify an exclusive ethical focus on paramount needs of the human populations (McDonald 2012).

Within the ecological and food security discourse, land, water and food production systems are paramount and these are considered below.

  1. A.

    Land and natural resources

Land and natural resources is central to social, political, and economic life in African urban centres because they are primary sources of livelihood, nutrition, income, wealth, and employment as well as a basis for security, status, social identity, and political relations with significant historical, cultural, and spiritual significance (Viet 2013). In these areas, land or natural resource tenure reflect the social, political, and economic relationship, whether legally or customarily defined, among the people, as individuals or groups (FAO2002). Land-related conflicts are common and have the potential to undermine both environmental stability and food security due to the investment gap in conflict managementinstitutions (ECA 2004). Land security is an integrative framework to manage and govern land-related investmentsand conflicts that take into account the interacting natural and social systems (Bizikova et al. 2013).

Competition for access to Africa’s land and natural resources is increasing due to large-scale land acquisitions for food production, resource mining, logging, and construction of social infrastructures, such as roads, rails, and ports (Viet 2013). Bizikova et al. (2013) described it as the contentious “land grab” phenomenon, which involves domestic as well as transnational companies within the continent. These activities have ecological effects reflective of a departure from the pristine condition with effects on biodiversity conservation through increased pollution, diseases, habitat destruction, etc. despite recent expansion of protected area network (Viet 2013; Osawaru and Ogwu 2014; Ogwu et al. 2014). The increased urban population is influencing land prices and land use patterns that are unsustainable and positioned to compound climate change effects because the land investments lack broad social, environmental, and economic objectives, and socio-ecological risk management.

In urban Africa, land legislation (both statutory and customary) struggles to be properly implemented (Cotula 2007). This, along with a weak tenure system permit people to mine their soils and extract natural resources to maximize short-term benefits, eroding the resource base, negatively impacting ecosystems, and undermining long-term agricultural productivity (Viet 2013). The establishment and proper enforcement of sustainable land legislation is key to having control over major decisions, such as what crop to grow, what techniques to use, what to consume, and what to sell (ECA 2004). In addition, urban agriculture is dominated by small-scale farming mainly for subsistent or barter trade with little to no concern for price controls, commercial marketing, regulated information, credit etc. However, with decreasing urban space due to increasing population and new development, urban agriculture remains a viable livelihood option that is likely to decrease rather than increase unless sustainable approach is incorporated. Prain and Lee-Smith (2010) gave an estimated value of 35% of urban African residents use agriculture as a livelihood strategy and highlighted its role in combating urban food security. Urban land use in Africa is influenced by prevailing environmental and technological conditions and continues to undergo a systemic transformation. Achieving long-term value in urban land investments should be an essential part of any SD agenda (Bizikova et al. 2013).

  1. B.

    Urban water issues in Africa

Africa has abundant water resources but these are not evenly distributed, and rainfall patterns are becoming increasingly unpredictable due to climate change. The elements of water security are water access, safety, and affordability (GWP 2000). Dos Santos et al. (2017) opined that water access in urban areas of SSA is inadequate due to population growth, rapid urbanization, poor infrastructure, and disparities in water availability. Meanwhile, access to clean drinking water is essential to human survival (Adams et al. 2018). As Africa’s urban population is set to double, the difficulties associated with providing sustainable water services may exacerbate and the traditional approach of one source, one system, and one discharge cannot close the water gap (Jacobsen et al. 2012).

Africa’s percentage of fresh water is about the lowest in the world and among the most polluted. Water is a valuable scarce urban resource and African governments must be responsible and accountable for providing sustainable water strategies and a framework to provide clean drinking water, sanitation services, and food (PACN 2010). SSA lags behind other regions in terms of access to improved water sources as only 56% of the population enjoy access to safe water, which falls short of the 75% global yardstick (Banerjee et al. 2008; UNICEF 2008). Urban dwellers are mostly responsible for their water needs. As a result, wells and boreholes are the primary source of water for 24% of Africa’s urban population mainly from Chad, Mali, Nigeria, and Sudan while 7% rely on lakes, ponds, springs, or other forms of surface water for potable water with vendors currently serving about 4% of the urban market (Banerjee et al. 2008). The current situation makes urban agriculture more challenging. Africa needs to modernize its water harnessing, provision, and purification technology by incorporating new methods like the roof, pavement, and urban water catchment to recharge its declining groundwater level and change from delivery of piped water to supply of point of use technologies (Wandiga 2015). UNICEF (2008) adopted the WHO/UNICEF Joint Monitoring Programme for Water Supply and Sanitation classification to categorized Africawater supply into improved drinking water and unimproved water sources based on whether its nature of construction is protected from outside (manly faecal) contamination (improved) or otherwise (as unimproved; see Table 1, UNICEF 2008). The table exposes the sensitive means of meeting the water needs of an increasingly urban population. Water is a decisive natural capital that if managed and used effectively can contribute to economic growth, SD and increased food and energy production in Africa (UNECA/ACPC 2011).

Table 1 Improved and unimproved water sources in Africa
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As climate change intensifies the challenges of African urban water resources, the design, construction and maintenance of water sector infrastructure became cost intensive. As a result, the water sector is heavily dependent on external support; yet recent field studies in Ghana, Kenya, Uganda, andZambia have indicated that the actions of many stakeholders in the water supply and storage sector undermine the provision of sustainable services (Harvey and Reed 2003).

  1. C.

    Food production systems

There is robust evidence that SSA has the highest proportion of urban food-insecure people (FAO2012). Food production system refers to all the processes and infrastructure involved in satisfying the food security needs of a population including the gathering/catching, growing, harvesting (production aspects), storing, processing, packaging, transporting, marketing, and consumption as well as the sustainable disposal of food waste (non-production aspects) (Porter et al. 2014). According to Porter et al.’s evaluation of the food production system, climate change is negatively affecting urban food security targets. However, food security is not only linked to climate risks or price volatility, but also to public regulations of goods and services (Janin and Suremain 2005).

Efforts to increase food production is increasingly important as 60% more food will be needed by 2050 (FAO2012). Changing urban consumption patterns determine the rate and nature of food demand, required growth and nutritional levels as a determinant of urban food security (Kearney 2010). Increases in urban farm-household income may provide as much as two to four times additional income, thus, improving their economic and food security conditions. Household food insecurity and poverty are unevenly distributed across urban Africa, with a number of the hotspot in areas peri- and suburban centres, which is characterized by a high population of new migrants, slow economic growth and land degradation. The land degradation in these areas also affects food production systems.

In addition, agricultural productivity in Africa is lower than other regions because a large proportion of African soils face severe constraints aggravated by water and wind erosion, soil mining and overgrazing that require careful land management (Garrity et al. 2012). Garrity et al. identified seven interconnected drivers, which may potentially shape the development of urban farming systems in Africa as: population; food security and poverty; markets and trade; natural resources and climate; energy; technology and science; human capital/knowledge sharing/gender, institutions, and policies. Among the most frequently cited trends are the rise of the African middle class, rapid urbanization and consequent shifts in food demand and downstream modernization of the food systems, a rapid shift in the labour force from farming to non-farm jobs, and rising competition over African farmland (Jayne et al. 2014). According to Jayne et al. the creation of new jobs in the non-farm economy is unlikely to grow fast enough to absorb the rapidly growing young labour force; hence smallholder urban agriculture will be a fundamental safety valve for absorbing much of the new labour force into gainful employment. The most direct consequence of exponential urban population growth is that the continent now has more mouths to feed with limited resources. These can be addressed by the range of adaptation options that exist across all food system activities like food processing, packaging, transport, storage, and marketing (Porter et al. 2014). In addition, a trade-off may be essential to ensure sustainability in urban food production systems.

5 Conclusion and Recommendations

The rapid rise in Africa’s urban population is causing a proportionate increase in food and energy prices. Adopting a ‘high politics’ approach is necessary to acquire funding, formulate SD policies, and make decisions to match the pace of urbanization and mitigate climate change (Hartmann 2009; Jayne et al. 2014). There is a need to strengthen the current foci of Africa’s regional and global alliances. Recognizing the relationships among SD elements will help to highlight cross-sectional challenges that require policy actions (Bizikova et al. 2013). Policy-makers should seek multidimensional ways of encouraging forms of urbanization that sustainably contribute to economic growth, increase job opportunities, and environmental sustainability than pursuing accelerated urbanization alone (Chen et al. 2014).

Moreover, urban agricultural across Africa invite a deeper understanding and analysis of the farming systems to inform evidence-based policy and decision-making (Garrity et al. 2012). Rwanda offers a model national sustainability agenda, which includes plans to integrate urban and peri-urban horticulture to increase urban food security and boost farmers’ incomes (Bafana 2016). Research findings suggest that African governments’ places a low priority on water provision without clear policy and regulations, which may potentially have a greater impact on sustainability (Harvey and Reed 2003). Africa has the potential to become self-sufficient in food production but the challenge of providing adequate supplies of water for agriculture must be addressed (PACN 2010). African governments, donors, and civil society should invest more in the human capacity of the populace to contribute to urban climate change adaptation and mitigation efforts.

Furthermore, there is a need to implement climate change adaptation strategies to reduce its vulnerability and also to adopt mitigating measures to achieve sustainable growth. This is necessary because while climate mitigation focuses on uprooting the causes of climate change, adaptation focuses on adjusting to the effects of climate change in order to reduce vulnerability and risk. In contrast to developed economies where the focus is on climate mitigation, both climate mitigation and adaptation are pressing issues in Africa (Sy 2016). In addition, governments should increase incentives to preserve urban environments so that the populace can get commendable returns from their land as an incentive for them to improve land management and agricultural production (Viet 2013; Hogarth et al. 2015). Sustainable alternative for power generation should be considered along with livelihood means for the increasing urban migrants. SD calls for conscious efforts towards sustainable environmental practices.

The impacts of urban climate change may be minimized through the communication and cooperation of various organization and stakeholders (Gemeda and Sima 2015). To this end, African governments must deepen their commitment to innovative policies to create jobs, tackle climate change, and improve urban agriculture (Ahenkan and Osei-Kojo 2014). Agriculture and food production remains important ingredients for SD in Africa hence, governments should monitor microclimate, adopt public–private partnerships to develop food production systems, fight against corruption and terrorism and promote value addition (Ojo and Oluwatayo 2016). The most important lesson is that the African environment is more resilient than conventionally thought and can probably support a higher level of population and more intensive agriculture but technological innovations and institutional developments are important elements to maintain a sound environment (Mabogunje 1995). Modernization of smallholder urban farms and their integration into the fast-growing agribusiness chains can help meet the livelihood needs of the increasing urban population and contribute towards enhancing environmental quality.