By 2050, millions of people living along coastlines, floodplains, and islands will be affected by flooding, while others will experience extreme drought, and South Africans will not be spared. These cities include two of the country’s economic hubs – Durban and Cape Town – which urgently need to adapt to address the growing physical risks associated with climate change.

Newly released report reiterates that cities in South Africa and across the globe need to adapt and mitigate the growing risks of climate change, warning of further dire consequences due to inaction

This is according to report titled: A strategic approach to climate adaptation in cities. It is cowritten by C40 Cities Climate Leadership, a network of large cities that are committed to addressing climate change, and McKinsey Sustainability, which aims to help all industry sectors transform to cut carbon emissions by half by 2030, and
reach net zero by 2050.

The document says that more than 90% of all urban areas across the globe are coastal and by 2050, more than 800 million urban residents will be affected by rising sea levels and coastal flooding. And while more than half of the world’s population currently lives in urban areas, this figure is projected to rise to 68% 2050.

Also, 1.6 billion people could be vulnerable to chronic extreme heat (up from 200 million today), and 650 million could face water scarcity It gives Cape Town as an example of a city already experiencing debilitating natural disasters.

After three years of poor rainfall, the city almost ran out of water in 2018 due rapid urbanisation and relatively high per capita water consumption. It had to introduce drastic action to reduce water demand. The report warns that by 2050, 685 million people in more than 570 cities could face a 10% decline in fresh available water. But cities including Cape Town, Amman in Jordan, and Melbourne in Australia, could experience much larger declines of
between 30% to 49%, while Santiago in Chile could face a decline of more than 50%.

“Cities are vulnerable to climate-related risks because the built environment can exacerbate climate hazards, and climate hazards can put pressure on urban systems. Buildings and roads, for example, absorb and re-emit the sun’s heat, causing what is known as the urban heat-island effect,” the document reads.

It says poorly planned infrastructure, such as paved-over streams, can interfere with
water drainage.

“Moreover, modern urban infrastructure and its operating systems are closely connected. A failure in one part of a network can affect another part, multiplying the damage,” the report says.

“Flooded roads, for example, can damage links to public transport. Storm surges and extreme heat can lead to power outages that knock out technology systems critical to homes, hospitals, and industries. To build climate resilience, leaders need to understand these connections.”

In 2018, a United Nations report found that from 1998 to 2017, climate-related and geophysical disasters caused 1.3 million deaths and incurred $2.9 trillion in economic losses globally.

The document acknowledges that because cities face different climate risks and have varying levels of vulnerability, options that could be considered are not equally feasible for each urban area. However, it suggests 11 actions that can be considered depending on the climate risk, and four which can be used by all cities to “build systematic resilience”.

“Some of the 15 actions, such as building barriers to protect coastal areas and retrofitting infrastructure, are complex and expensive. Others, such as planting trees next to streets and initiating behavioural-change programmes to conserve water, aren’t. Examples from all over the world, in both advanced and developing
economies, demonstrate what’s possible.”


On addressing diminishing water availability, it says not only are behavioural-change programmes, which educate people about water usage and reducing consumption, crucial, but so are efficiency improvements such as reducing water leakages. It cites the 2017–18 Cape Town water crisis, where the city introduced a campaign to encourage residents to make behavioural changes and avoid “day zero,” the day the city would run out of water.

“The campaign communicated that day zero was a real possibility; sponsored positive activities, such as school competitions to lower water use; and used a series of nudges, such as promoting two-minute songs to sing in the shower, to prompt behaviour change.

“Cape Town successfully reduced water use by more than 50% from 2015 to 2018, with residential water usage declining significantly,” the report reads.

Programmes that support a change in behaviour are generally low-cost because they require no new physical infrastructure, and they can have significant impact. But researchers say they do need a fair degree of stakeholder management, because they must be clearly defined, imaginatively devised, and well communicated to be effective.

The first step should at least include targeting people who consume the most water, as it makes the most sense in terms of practicality and social equity, the document reads. On efficiency improvements, “nonrevenue water”, which is water that is pumped but then lost or unaccounted for, is a major challenge for many cities. The scale of nonrevenue water loss is significant. In the United States, it is about 16%, but in other countries it is much higher such Turkey (as between 35% to 60%), and South Africa (36%).

The research says a common tactic to address physical losses is conducting a full audit to identify weaknesses and leaks, and then repairing them. Installing meters can address commercial losses. It gives an example of Seosan in South Korea, which devised an integrated approach to cut down on nonrevenue water in 2016. The city focused on reducing water leakages and implementing smart meters that tracked customers’ hourly water usage digitally. The project resulted in a 20% improvement in the ratio of water that was used and paid for, and it reduced leaks by
190,000 cubic meters of water per year.


The report says to reduce the risks of inland and associated urban flooding, two actions are broadly applicable: river-catchment management and nature-based sustainable urban drainage solutions (SUDS). River-catchment management promotes the development of natural ecosystems and river flow. This includes reforestation with indigenous trees and shrubs along river embankments that can reduce the runoff entering rivers and alleviate the risk of flooding downstream.

Another option is to focus on downstream river management through strategies such as improving drainage along riverbanks. Here it gives Durban as an example. While still in its design phase, the eThekwini Transformative River Management Programme near the city, aims to manage the 7400km of rivers and streams in the metro to improve water quality and stem flooding.

“Catchment management involves many stakeholders, including scientists, policy makers, planners, nongovernmental organisations (NGOs), and residents. Given the effectiveness of catchment management in reducing flood risk, its potential for risk reduction is likely to outweigh the costs for many cities exposed to this hazard,” the researchers say.


They warn that the risks of climate change are severe, and extreme heat, coastal flooding, drought, wildfires and tropical cyclones will become more frequent. It is for these reasons why cities must invest in adaptation as well as mitigation. Adaptation is especially crucial for protecting vulnerable populations, such as low-income communities, people with disabilities, children, some minority groups, women, and the elderly.

“Members of these groups may be at higher risk for climate-related damage. For example, continued rapid urbanisation and, in some geographies, the emergence of climate risks outside of cities are leading to increased populations in informal settlements,” the document reads.

“These areas often lack the resources and adaptive capacity to withstand major events, such as floods or extreme heat.”

While the report only mentions Cape Town and Durban as examples, according to the Institute for Security Studies (ISS), five months into 2021, all nine provinces experienced floods on top of a series of devastating fires in the Western Cape. And the International Disaster Database has recorded 90 noticeable weather-related disasters in the country since the early 1980s. These events caused R95bn in associated economic losses and directly affected around 22 million people.

The ISS says that although it is unclear if these hazards are a frequent occurrence, there has been a 57% increase in recorded events over the past two decades compared to the preceding two. It also warns that the frequency and intensity of weather disasters combined with a growing and urbanising population, poor land-use practices, growing informal settlements and slow deployment of resilient infrastructure, is likely to result in significant losses.

And this is line with the Global Commission on Adaptation, which estimates that climate change could push an additional 100 million people in developing countries below the poverty line by 2030.

By: Amy Musgrave