Climate change and extreme weather events are punishing cities. They will have to get more resilient. But how?
Following an inconclusive end to proceedings at COP26, many are questioning what comes next. Pledges made to end deforestation, cut emissions and electrify transport are to be applauded, but the conference alighted on one area that must be a focus of policymakers in the immediate future. That is, making cities more resilient to climate disasters.
In recent years it has become clearer that urban areas are particularly vulnerable to extreme weather events, ranging from floods and heatwaves to earthquakes and tsunamis. The proportion of people who have experienced these sorts of things is going up. For instance, 2020 saw more climate and weather disasters than any other year in the US. According to official figures, 22 individual events each caused around USD 1 billion worth of damage. It’s getting worse, with 18 incidents occurring in the first six months of 2021. Meanwhile, cities themselves house a greater proportion of the world population. In 1950, just 30% of the people lived in cities, according to UN figures. Today that proportion has climbed to 56%. By 2050, it is anticipated to be 68%. Therefore, the subject of resilience is becoming a regular talking point among policymakers, urbanists and citizens.
Making cities less vulnerable is a complicated business. David Hsu, Associate Professor of Urban and Environmental Planning at MIT, reckons that future-proofing urban areas involves two tasks – making cities tougher, but making them less costly to the environment too. “There is no way we can make any city durable enough to withstand climate change and the trajectory we’re on,” he says. “So cities need to do two things: reduce carbon emissions and become more resilient. They are the locus of consumption – so they need to reduce energy, material and water consumption.”
Re-thinking cities to be more climate-friendly will take a coordinated approach. The Global Resilient Cities Network (GRCN) is an organisation that forges links with urbanists and policymakers from cities around the world to share approaches on making towns tougher and safer. Its executive director Lauren Sorkin cites the importance of appointing a chief resilience officer (or CRO) to oversee risk. “A figure who is responsible for resilience is imperative to keeping cities safe,” she says. “Many cities around the world are staring down the same kinds of challenges, dangers and insecurities, but an in-depth knowledge of a location is crucial.”
Sorkin draws attention to the GRCN’s recent work in the Asia-Pacific. Co-launching the Temasek Foundation Urban Resilience Programme (TFURP) with a cadre of collaborators, it brought together city bigwigs from the region to draw up an accord on how to accelerate investment in urban resilience.
This approach is a smart one. Modernising cities to be more robust is a costly business. But such outlays pale in comparison to inaction according to research from The World Bank. The institution reckons that low- and middle-income countries get USD 4 in benefit for each USD 1 invested in resilient infrastructure, citing the estimated USD 18 billion per year cost those countries incur from climate-related disasters.
“Resilient infrastructure is not about roads or bridges or powerplants alone. It is about the people, the households and the communities for whom this quality infrastructure is a lifeline to better health, better education and better livelihoods,” World Bank Group President David Malpass writes in the report. “Investing in resilient infrastructure is about unlocking economic opportunities for people. This report offers a pathway for countries to follow for a safer, more secure, inclusive and prosperous future for all.”
Resilience is, therefore, not just about physical assets, but about quality of life and ensuring the safety of vulnerable folk. Hsu observes that weather events make cities preexisting problems a lot worse. He draws on Massachusetts as an example. The state is currently at risk of losing 160,000 homes due to rising sea levels, but the housing market is already booming, with many people priced out. “This is true in a lot of places where climate change exacerbates problems that were already there,” he says. “Heatwaves are the biggest killers and flooding is the biggest damager of property. Every city in the world is in the coming years going to discover new risks that they didn’t know about before.”
Is technology the answer? Perhaps. Cleaner, more sustainable means of generating energy have come down in price, so too will sustainable transport and other commonplace solutions. But innovation and engineering projects of staggering scale are underway also. For instance, China has a plan to make 30 cities less prone to flooding by replacing concrete streets and pavements with materials that have sponge-like properties. Rather than roads turning into rivers, water will simply soak through into sewers below. In London the Thames Tideway Tunnel (branded the ‘super sewer’) will stop raw sewage from flooding into the river after heavy rain. It’s due to be 25 km long and expected to cost GBP 4.2 billion.
There are grassroots initiatives to make cities more resilient too. The concrete and tarmac covering cities makes them hotter by reflecting the sun, so more trees means cooler urban areas. Researchers at the University of Wisconsin found that US cities require 40% tree coverage to perceptibly bring down city heat, a proportion of foliage that seems improbable for most urban jungles. But an approach of city greening has emerged in Japan and taken root elsewhere. Miyawaki Akira, an ecologist at Yokohama National University, has pioneered an approach where unloved areas in cities are populated with a variety of trees, bushes and vines to cool the air through evaporative transpiration. The result is an array of micro forests from Asia to Europe that quietly bring temperatures down.
As cities increase in size and population in the coming decades, the number of issues they are likely to face will multiply. However, planners, technologists, designers and inventors are drawing up interdisciplinary strategies to better protect urban environments and the people who live there. There is a lot at stake – built-up areas are where new ideas, economies and societies flourish. When cities fail, civilization suffers.