Key message 3 – Access to local public goods and services aids resilience to environmental shocks and stressors.
A sustainable, liveable, and productive city is one that is resilient to environmental shocks and stressors. These acute shocks—such as heatwaves or flash floods—and chronic stressors—such as air pollution or sea-level rise—are currently impacting cities and will do so increasingly. The investments in local public goods and services that developing country cities are already grappling with, which help citizens manage these changes, will become more important. In some cases, they can also contribute to mitigation. Here, we discuss two examples, although there are many more.
Water and sanitation
Equitable access to clean drinking water and a well-functioning sanitation system is a critical component of a resilient city. Currently, accelerating climate change is worsening already limited water access, with poor, often informal communities suffering from water shortages arising from frequent droughts. Harsh storms are damaging water and sanitation facilities, and heavy rainfall or sea-level rise is causing sewage to spread across communities.
The latter has been studied in Dar es Salaam, Tanzania, showing heavy extreme rainfall leading to the spread of cholera (Picarelli et al. 2017). This impacted citizens’ health either directly—as residents encounter pathogens—or indirectly—as precautions reduce citizen’s ability to work, thus lowering their income and adaptation ability. The spread was worse in areas with poor local public goods—specifically, water, sanitation, and roads. Figure 3 shows the considerable variation in water and sanitation provision across urban areas in Africa, with only 13% provision in Liberia compared to 60% in neighbouring Cote D’Ivoire.
As populations rise in most developing country cities, waste generation increases at a faster rate (Kaza et al. 2018). For example, in Kigali, waste generation is increasing at four times the rate of its population growth (Rajashekar and Bowers 2019). As a result of this growth, stretched collection systems see waste either being burnt or dumped by citizens wanting to dispose of it in the least costly way. Dumped waste can block drains and contaminate aquifers. This leads to the acute shock of localised flooding common in developing country cities, like Accra (Amoako and Frimpong Boamah 2020).
Meanwhile, burnt waste emits super air pollutants like black carbon and methane. These pollutants absorb sunlight strongly, increasing local temperatures and urban heat island effect at a rate much higher than carbon dioxide (Schmale, Shindell et al. 2014). They also have global GHG consequences, with black carbon emissions contributing to over 2 to 10% of global carbon dioxide equivalent emissions, and methane at waste disposal sites contributing a further 3 to 4% (Reyna-Bensusan et al. 2019). Tackling waste management thus, contributes to both adaptation, mitigation, and local health and productivity benefits.
While there are some challenges we can predict and some decisions where the outcomes are reasonably clear, others are clouded by uncertainty. For example, flash flood-prone areas are fairly well-known, and we can begin to address this now (UNESCO 2022). Other challenges are more uncertain, such as how vulnerable certain neighbourhoods will be to sea-level rise. The risk to cities will depend on the world’s commitments and ability to manage global warming, but also interacts with how they themselves will change—thus requiring longer term adaptation planning for the future (Collier et al. 2018). Despite different levels of uncertainty, many of these decisions must be made today to avoid locking into unfavourable outcomes in the future.