Population dynamics, urbanisation and climate change in Africa’s intermediate cities: what can family planning contribute?

Africa’s large cities are rapidly urbanising and are becoming expensive, regressive and unhealthy; hence, secondary or intermediate cities have become the continent’s backbone for absorbing most of the urban population growth. Africa’s intermediate cities will be home to more than half its urban population by 2030. However, these cities have considerable investment gaps in critical infrastructure: consequently, they are less resilient and face disproportionate disasters and risks of climate stressors and other environmental challenges. The vulnerabilities of Africa’s intermediate cities are exacerbated by rapid urbanisation and inappropriate planning. As Africa’s intermediate cities continue to experience population growth and rapid urbanisation occasioned by a youthful population, high fertility and excess of births over deaths, family planning is one of the most critical investments that city leaders and officials can make to ensure a slow urban population growth and thus buy sufficient time for governments to put critical hard infrastructure and appropriate planning in place to support healthy living. Increased investment in family planning will contribute to prosperous and resilient intermediate cities in Africa.


Introduction
As Africa continues to urbanise, secondary or intermediate cities are increasingly becoming a buffer for the ever-expanding urban population. The United Cities and Local Governments (UCLG) defines intermediate cities as those with a population of less than one million, though this figure may vary from one country to another (Bolay and Kern, 2019;Rankin, 2019). An intermediate or secondary city may be the capital city of a second-tier administrative unit or the seat of a country's sub-national government such as a county, province, or state. It may also be a cluster of smaller cities within a metropolitan area (Rodríguez-Pose and Griffiths, 2021). Intermediate cities are important and are home to more than half of the world's urban population (Bolay and Rabinovich, 2004;Bolay and Kern, 2019). They play a critical role and serve as a linkage between rural and urban centres, albeit they are often not prioritised in national planning.
The importance of intermediate cities is often underestimated in research and discourse on issues regarding population dynamics, urbanisation and climate change. Most studies on population dynamics and the crises of urbanisation and climate change have focused mainly on large and capital cities (Hove et al., 2013;Zulu et al., 2011). Massive population increase in many of Africa's major cities has overwhelmed infrastructure, thereby causing difficult access to basic services such as transportation, housing, quality and affordable education and health care, as well as adequate sewage and waste management. Recent evidence shows that some of Africa's major cities are regressing, thus leading to the exacerbation of environmental and socioeconomic challenges (UNICEF and UN Habitat, 2020).
Africa's large cities such as Cairo, Lagos, Kinshasa, Dar es Salaam, Johannesburg, Nairobi, Lilongwe, Accra, etc. have received much policy and programmatic attention while intermediate cities are less catered for. However, around fifty per cent of the world's urban population lives in intermediate cities (Bolay and Kern, 2019). Evidence is sparse on the proportion of the African population living in intermediate cities. However, available evidence shows that about a third of the sub-Saharan African population lives in secondary or intermediate cities compared to ten per cent who inhabit large cities (Satterthwaite, 2016). Thus, intermediate cities in the region deserve more programmatic and policy attention.
Some of the recent global health threats, such as the climate change crisis, appear to affect the residents of Africa's intermediate cities more than those who live in the continent's large cities. For instance, many of Africa's intermediate cities are agrarian societies whose crop production is affected by droughts, crop failure and famine due to climate change (Guzmán et al., 2009). Other climate change crises that affect intermediate cities are natural disasters, flooding and health hazards (Kumar, 2021;Leichenko and Silva, 2014;Satterthwaite, 2008). Recently, severe flooding and landslides due to heavy rainfall led to the death of nearly 500 people with about 40,000 individuals displaced in KwaZulu Natal, South Africa (Reliefweb, 2022). Further, scholars and policymakers have warned that many intermediate cities, particularly those in coastal or equatorial areas, may face disproportionate risks of climate stressors and shocks (Harman, 2021;Kumar, 2021;Zerbo et al., 2020). The vulnerabilities of these cities are exacerbated by rapid urbanisation, inappropriate planning, and limited financial, infrastructural, and human capacities occasioned by poor government attention. Thus, twenty-first century urban and territorial planning needs to give more attention to intermediate cities.

The growth of Africa's urban population and intermediate cities
Historically, the period following the Second World War was characterised by two remarkable global features: the vigorous pursuit of socio-economic development and rapid population growth (Mathur, 1984;UNICEF and UN Habitat, 2020). These two phenomena led to rapid urbanisation, particularly in developing countries. Figure 1 shows that many African large and capital cities have experienced rapid population growth. Many of these cities have become unmanageable. Some of the challenges faced by the residents of these cities in Africa include overcrowding, limited job opportunities, poverty and poor liveability, housing problems, air and noise pollution, conflict and heightened criminality, as well as heavy trafficwith commuters losing several hours to gridlock daily. These challenges largely stem from the problem of rapid urbanisation, with the large number of residents occupying a relatively small amount of space. For instance, in Nigeria, more than 15 million individuals live in the smallest state, Lagos, which has a land area of just 3,577 km 2 , while the largest, Niger State, has a total population of less than 4 million occupying 76,363 km 2 (Lagos Bureau of Statistics, 2022; Niger Bureau of Statistics, 2012Statistics, , 2022. In Ghana, Accra covers an area of 225.67 km 2 with an estimated 4.2 million population (Atenvo, 2022 The situation of high population density and rapid urbanisation is common across large cities in Africa. As a result, intermediate cities have become attractive to rural-urban migrants in many countries, thus leading to an increasing percentage of the urban and national population residing in intermediate cities (Satterthwaite, 2016). Several secondary or intermediate cities in many African countries have experienced phenomenal growth in population size. Figure 2

Roles of family planning towards building resilient and sustainable intermediate cities
Future population growth will mainly happen in urban areas of developing countries, particularly in sub-Saharan Africa and south Asia (Saghir and Santoro, 2018;Srivastava, 2020). Africa's urban population growth rate averaged around 3.9 per cent (World Bank, 2022b) and the continent's urban population is projected to increase from 472 million to over 1.3 billion by 2050 (Mo Ibrahim Foundation, 2015). Intermediate cities in Africa will also continue to grow and will account for more than half of urban population growth by 2030 (Roberts, 2015;Satterthwaite, 2016). Although rural-urban migration is a contributing factor to urbanisation in Africa, natural population increase (excess of births over deaths) remains a major determining factor (Adedini et al., 2022;Harpham et al., 2021;Montgomery et al., 2013). While life expectancy has continued to increase in Africa, fertility rates have remained high, with the average total fertility rate in 2020 standing at 4.6 (World Bank, 2022a). And, while progress has been made, stalls or reversals in fertility decline have been experienced in many countries (Schoumaker, 2019). Thus, to achieve fertility transition in Africa's intermediate cities, urgent action is required.
The role of family planning in ensuring fertility transition, and healthy and sustainable intermediate cities, is crucial, particularly in sub-Saharan Africa. United Nations' Sustainable Development Goal 11 aims to make cities and human settlements inclusive, safe, resilient and sustainable. In line with this goal, family planning can serve as a strategic tool and contribute toward building prosperous, healthy and sustainable urban areas in Africa. According to the AfDB & Alliance's (2022) report, family planning services have desirable effects at an urban and rural level and can serve as part of a critical economic empowerment programme especially for women to enable them to control their fertility and desired family size and then align their occupations with maternal or family obligations. However, as of 2022, an estimated 20 million urban women of childbearing age in African cities who would like to use family planning methods do not have access to reproductive health services (Standard, 2022). Poor access to quality family planning often leads to unintended pregnancies, unsafe abortion or unwanted births.
Due to the high unmet need for family planning and high rates of unintended pregnancies and unwanted births, many African cities will continue to have high fertility and rapid population growth. As a result, cities will find it difficult to optimally meet basic needs such as housing, adequate nutrition, potable water, road, sanitation, education, healthcare, employment, etc. With rapid urbanisation, no amount of investments in hard infrastructure by city Mayors and municipal officials will be able to keep pace with rapid urban population growth in African cities. Intermediate cities in particular will face much greater challenges than large cities due to gaps and neglect of the former in terms of investments in critical infrastructure. As African countries strive to build the necessary infrastructure to make their intermediate cities resilient and prosperous, family planning will be one of the most critical investments to help cities gain sufficient time for the proper city and territorial planning that is congruent with sustainable and healthy socio-economic development. This will contribute to the wellbeing of individuals, families, communities and the nations at large. Investment in family planning will contribute to climate change adaptation and promote rights-based development. Africa's intermediate cities will benefit greatly from family planning programmes that respect human rights. Africa must make increased investments in family planning to address the unmet need for contraceptives, especially among the vulnerable urban population, including the urban poor, slum dwellers, and adolescents.

Frontiers for future research
Given the critical roles of intermediate cities in Africa, more research on a wide range of issues (such as environmental, socioeconomic, health, urban dynamism and resiliency) is needed in the relatively less known African cities. Currently, little evidence is available about how intermediate cities respond to their various environmental challenges and climate change. There is an urgent need for research on the crises of urbanisation and climate change in Africa's intermediate cities.