It’s a vicious cycle, but there are other solutions.
Here’s how eight cities are taking some of the heat out of their summer.
Medellin, Colombia: Plant trees in the streets, not just in parks
When it gets really hot, people can stay indoors with air conditioning, but not everyone has that luxury and – well, who wants to say all the time?
Temperatures in and around these regions have dropped by 5.5 degrees Fahrenheit (about 3 degrees Celsius), and officials expect that to drop as much as 9 degrees Fahrenheit (5 degrees Celsius) before 2030.
Kathy Baughman McLeod, director of the Atlantic Council’s Adrienne Arsht-Rockefeller Foundation Resilience Center (Arsht-Rock), told CNN, “Urban forests are the best thing for the heat of the city.” “Medellin has reduced the average summer temperature in the city, which is significant.”
By 2019, the city had planted over 8,000 trees and over 350,000 shrubs. It uses an area under an elevated metro line to collect rainwater that flows down from the bridge, capturing it in a system of pipes to help deliver water to the green belt.
Vienna: Splash, splash, splash
Like much of Europe, many people in Vienna don’t have air conditioning, so water is a big part of how the Austrian capital keeps cool.
For those who don’t have time to take a dip in the Danube, the city offers cool parks with mist-sprayed “trees” where people can either “bath,” or sit nearby to enjoy the cooler temperatures around them.
Vienna has plenty of water fountains to keep people hydrated — more than 1,100 for its 1.9 million population — which is important in preventing heat-related illness.
“Home air conditioning may sound like a quick and easy solution. But it’s not a long-term sustainable solution because of the energy source and the waste heat of the unit,” McLeod said. “So it’s important to think about how to get more airflow, use water features and open windows in some of the oldest buildings. Nature-based solutions are best for extreme heat.”
Abu Dhabi, United Arab Emirates: Use old cooling techniques and modernize them
Parts of the Middle East are the hottest inhabited places on Earth. Temperatures in Abu Dhabi can soar above 120 degrees Fahrenheit (over 50 degrees Celsius). Air conditioning is seen as a necessity, and people spend a lot of time indoors.
But people here didn’t always have air conditioning, and an ancient Arabic architectural cooling technique has made a comeback with a modern twist.
Mashrabiya Often seen in Islamic architecture refers to latticed screens, sometimes around a small balcony, that diffuse sunlight and keep buildings cool without blocking the light completely. They are designed to encourage a breeze and provide respite from the heat within a building. The idea is basically to stop direct sunlight landing on the exterior of a building.
The technique helped reduce the building’s air conditioning requirements by 50%. Cool huh?
Miami: Target Hit Trap
In many cities, catching a bus means long waits. If it’s really hot, the wait can be even more punishing—unless, of course, that bus stop is thoughtfully designed to include natural shade.
Medellin, Colombia may have proven that urban forests, or planting more trees, can cool a city, but Miami’s Dade County has put a lot of thought into which parts of the city need cooling the most.
And that they have. There are now 71 green bus stops in the country, most of them by communities who petitioned the government for resources to green their own bus stops.
To make it more fun, the organizers also organized a haiku poetry competition, and selected the top 10 to be carved on the pavement at the main stop.
There are also trees
Miss their bus – How they wave
Their very sad arms
– Ariel Francis
Athens: Work with what you’ve got
Not every city has an ancient aqueduct at their disposal, but the Greek capital, Athens, does. Hadrian’s Aqueduct was once the main source of water, using a pipe that worked with gravity to flow water from its source to the city for human consumption.
The water is not potable today, but the city is looking at ways to salvage the 800,000 cubic meters of water that flows into the sea as waste each year. One use would be to irrigate the new greenbelt to run the length of the 20km structure, which would help extract heat from the surrounding areas. Water will also be used for misting as in Vienna.
Even for cities without infrastructure so old, Athens is a good reminder that defunct water systems can sometimes be revived.
Los Angeles: Paint the city white
This one is a little more controversial.
Some cities have experimented with white roofs to reflect sunlight and keep buildings cool, but Los Angeles is taking the picture a step further. the whole road Dark materials like white asphalt absorb sunlight and return that energy to the air as heat. Painting asphalt white theoretically nips that process in the bud, and leads to cooler air temperatures.
That means if you’re a few blocks away, white streets may help you feel cooler, but if you’re on the street, you may actually feel hotter.
Still, LA is continuing the program to see what works and what doesn’t. It currently uses a grayish-white substance called Coolsil, once used to help hide grounded aircraft from satellites, but it’s possible that other types of paint might produce different results.
Ceiling painting has had greater success.
Results vary depending on the heat and materials the roof is made of, but in places like Ahmedabad, India, where it gets seriously hot, cool roofs have shaved 3-8 degrees F off home heat. According to Berkeley Lab’s Heat Island Group, a black roof can be 54 degrees (about 30 Celsius) hotter than a white roof.
Another option is green roofs. Cities all over the world have created “gardens in the sky” to cool buildings.
Paris: Get really organized
The French capital became seriously hot.
Temperatures there have topped 104 degrees Fahrenheit (40 Celsius) this summer, but the combination of tall buildings, limestone monuments and busy asphalt streets means it can feel even hotter.
The city has a strong urban heat island effect, where on summer days it is often 18 degrees hotter in the city center than in the Parisian hinterland.
But Paris Mayor Anne Hidalgo is credited with some of the world’s most innovative measures to combat heat, and the city’s heat plan is truly comprehensive.
Like Vienna, Paris uses fog machines on hot days. In addition to its many traditional fountains, there are dozens of new “splash fountains,” which are very shallow pools with a waterfall-like effect.
Paris’ heat plan has a register that identifies the most vulnerable people, so officials can check on them by phone and give advice on staying cool. Kindergartens get temporary air conditioning in their classrooms, and public parks and pools are open long hours into the night. And like L.A., Paris is trying to remove heat from streets and sidewalks by “passivating them” using more porous materials. Now that sounds like a plan.
Seville, Spain: Name your heat wave
The world has been naming hurricanes, cyclones and typhoons for decades for a reason: A named storm makes you sit up and take notice. The southern Spanish city of Seville is taking this approach with heat waves, becoming the first in the world to do so.
The July heat wave there was named Joe.
“The naming of heat waves is a positive thing because it means we understand how lethal they are, and that they are here to stay. This is not a static heat wave,” says MacLeod of Arshot-Rock. “It’s something we’re going to live with for a long time, no matter what we do with our emissions.”
But there’s more to what Seville is doing than naming. Arsht-Rock is working with Seville on a new classification system for heat waves based on projected negative health consequences. The idea is to avoid scientific jargon that most people don’t understand and link warning levels to what heat waves can do to people.
“Besides physical intervention for heat, naming and categorizing heat waves is the best, most immediate thing you can do,” McLeod said. “Because that’s the point – the heat is killing people, and it’s because people aren’t aware of the scale of the problem.”
CNN’s Taylor Ward, Schaums Elwazar and Vanessa Coe contributed to this story.