These 7 cities are tackling heatwaves with innovative solutions

This article was originally published in August 2022. It has been updated in May 2023 with new data for Paris.

Heatwaves are making cities some of the hottest places to be.

City infrastructure – like roads and buildings – absorbs heat and then releases it back into the city, meaning the highest temperatures in a heatwave are often in urban areas.

From Europe to China, India and Pakistan, the United States and Africa, this has been bad news for cities as temperatures have reached record highs.

Almost 90 cities issued heat alerts in the extreme weather over the summer of 2022, according to the United Nations Environment Programme.

But cities are learning to tackle extreme heat – sometimes with ingenious solutions.

Here are seven examples.

In a city that regularly hits 40C in the summer months, it’s perhaps no surprise that Seville was the world’s first city to categorize heatwaves in the same way that the US and Asian countries name hurricanes, reports Bloomberg.

To tackle the increasing heat, more awnings have been installed across the Spanish city. “We call it a policy of shade,” the city’s mayor, Antonio Muñoz, told Bloomberg. “It’s just one of the many things we need to do if we want to be able to use the streets – from children playing to people who want to do their shopping or just sit outside and talk.”

Seville also plants 5,000 trees a year, is switching to construction materials that reflect heat and is installing more public fountains, reports Bloomberg.

In Greater Sydney, an area covering 1.3 million hectares around Australia’s capital city, there are plans to increase the tree canopy by planting five million more trees by 2030.

Trees help to cool cities by providing shade and moisture. They also naturally absorb and store carbon dioxide, which helps to combat climate change.

In Los Angeles in the United States, city authorities started experimenting with painting streets white back in 2019.

The aim is to bounce the sun’s rays back into space, cooling the surrounding area.

Ten streets in ten neighbourhoods have been painted so far with the reflective coating, according to the website Reasons to be Cheerful. On hot days, the white paint cools the road’s surface and the surrounding area, the city’s sustainability officer says.

In Abu Dhabi in the United Arab Emirates, climate change is predicted to push average temperatures well above 50C in the second part of the century, bringing extreme heatwave conditions that could make the city unliveable.

But innovative design can help buildings deflect heat. One example is the Al Bahar Towers. The 26-storey building is fitted with computer-controlled folding screens that open and close to provide shade depending on the sun’s position, explains consulting engineers, Arup.

Heatwaves across France broke temperature records last summer – with the capital, Paris, reaching 36C in August 2022 – while an April 2023 study found that Paris had the highest heat-related mortality relative risk of 854 European cities.

Paris is responding to the heating effect of the climate crisis by creating 800 ‘cool island’ spaces across the city. These are listed on an app and include parks, water fountains and public buildings like swimming pools and museums.

The spaces can be between 2C and 4C cooler than surrounding streets. Paris also plans to plant 170,000 trees by 2026.

Planting greenery on rooftops can help cities keep cool, and Rotterdam in the Netherlands recently demonstrated this with the Rotterdam Rooftop Walk initiative.

The city hopes to green over 900,000 square metres of rooftops. By storing water, rooftops planted with vegetation can also help reduce flooding.

Green roofs can reduce ambient temperatures in a city by up to 15C, according to the United States Environmental Protection Agency.

In Colombia, the country’s second biggest city, Medellin, has created a network of 30 shady routes across the city known as ‘green corridors’ to fight heatwaves.

According to Reuters, thousands of native trees, palms, bamboo and tropical plants have been planted around sidewalks, parks and busy traffic routes, providing shaded places for people to travel and gather.