OPINION: As climate threats grow, what can cities do to cope?

Friday, 23 July 2021 11:15 GMT

Visitors walk along an elevated walkway connecting giant concrete tree-like structures called Supertrees at Gardens by the Bay in Singapore May 28, 2014. REUTERS/Edgar Su (SINGAPORE - Tags: TRAVEL SOCIETY)

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* Any views expressed in this opinion piece are those of the author and not of Thomson Reuters Foundation.

From heat-reflecting roofs to waterways that fight flooding, climate-smart ideas bring lots of side benefits

Brodie Boland is a partner in McKinsey & Company’s Washington office. Milag San Jose-Ballesteros is C40 Cities’ regional director for East Asia, Southeast Asia and Oceania.

A green and friendly oasis in the bustle of central Singapore, Bishan-Ang Mo Kio Park was long defined by a 3-kilometer concrete canal that ran along its southern border. The canal often overflowed, flooding nearby roads.

Beginning in 2009, Singapore stripped away the concrete, converting the canal into a meandering river. The result is not only more beautiful but provides better drainage and water quality.

Even the local wildlife approves. The new waterway has brought more biodiversity to the park, including otters and a wide variety of birds.

This effort is an example of a growing trend in cities around the world; the use of natural features to manage the movement of water and reduce the risk of flooding. More broadly, it is an example of how cities are adapting to the reality of a rapidly changing climate.

Cities are on the front lines of climate change. Throughout history, the world’s most prosperous cities, as major commercial and trading hubs, have been found on coastlines and the floodplains of major rivers. That makes them uniquely vulnerable to rising seas and flooding.

At the same time, buildings and roads absorb and reflect the sun’s heat, making cities considerably hotter than surrounding areas. Historic decisions to pave over streams and green spaces reduce the protection offered by trees plants and natural drainage.

The impacts of climate change are not felt by all residents equally. Poorer communities, the sick, and the elderly are more at risk.

For example, rapid urbanization is leading to bigger, more crowded informal settlements, and these often lack the resources to withstand cyclones or flooding. The challenge of ensuring that those who contributed least to climate change don’t suffer the most is both global and local.

Just this month we have seen the immediate threat posed by climate change. Extreme heat and wildfires have claimed hundreds of lives in Western Canada and the United States. Hundreds more have died or are unaccounted for in unprecedented floods in Germany and Belgium.

Billions of dollars are spent each year to rebuild the homes, roads and critical infrastructure destroyed by climate-related disasters. That is why action is needed now to protect residents.

However, there is no clear guidance on what action should be prioritized. While many mayors are already investing to build the resilience of their cities, we know that many other leaders are looking for guidance on where to begin. 

With this in mind, C40 Cities and McKinsey Sustainability set out to help in identifying a set of high-potential actions that cities can consider. 

Some of these actions build systemic resilience, improving a city’s ability to withstand and recover from a range of hazards. Almost all cities should develop a basic understanding of climate risks and their impact, incorporate these risks into planning, develop early warning systems, and ensure financial backstops for damages.

Other actions are hazard-specific, meaning that they reduce the impact of a particular threat, such as heat or floods, or enhance a city’s ability to recover from it.

They include installing cool roofs, wetland restoration, planting street trees, and river catchment management. In each case, there are real-life examples of how these can work.

When Madrid’s Mercamadrid fish market installed a white-painted sun-reflecting roof, for example, temperatures inside the building fell by 5 degrees Celsius.

Many of these actions don’t only build resilience, but also provide additional benefits like cutting emissions or air pollution.

Planting street trees brings shade and reduces temperatures, while making cities more beautiful; Medellin’s Green Corridors project has done both.

Retrofitting public infrastructure can be expensive up front, but can ultimately pay for itself. According to the U.S. National Institute of Building Sciences, building retrofits to make structures more resistant to hurricanes can create $6 in value for every $1 spent.

Improving drainage reduces the risk of flooding, and is also good for the creatures who live in and along river banks, as the otters in Bishan-Ang Mo Kio Park in Singapore can attest.  

Every city, regardless of resources, can do something. Some of the 15 actions are expensive, such as building barriers to protect coastal areas. Others, such as planting street trees and initiating behavioral-change programs, are not.

During the 2017-18 water crisis, Cape Town introduced a creative campaign to encourage residents to curb water use. The campaign sponsored 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.  It worked: Cape Town avoided “day zero,” cutting water use by more than half.  

The climate crisis is already underway, and lives, livelihoods and infrastructure are already at risk. Cutting emissions is critical, but we must also act now to protect our cities and communities from the reality of a changing climate.

Our ambition is to provide cities with guidance that can help to build resilience, and become more livable, healthier and safer places for all.

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