Want to Stay Cool in a Summer of Extreme Heat? Inspiring Solutions from 5 Global Cities
Public realm innovations to cool people and places
In the U.S., communities face more days of extreme heat than ever. Extreme heat is widespread: more Americans face exposure to extreme heat than to floods or wildfires, and heat kills more people than any other hazard associated with climate change. Temperatures over 90 degrees Fahrenheit are a strain on all households, but especially those in low-income communities, where people are less likely to have air conditioning and more likely to struggle to afford higher utility bills.
Recent years have put a spotlight on the trend toward hotter days. June 2024 was the hottest June on record, completing a 13-month cycle of record-setting high temperatures. In 2022, Seville, Spain, began naming and categorizing heat waves much like other nations name hurricanes and typhoons. According to the non-profit Climate Action Tracker, if the current level of emissions and the latest policies to fight climate change continue, the result will be an average increase in global temperatures of nearly 5°F by the end of the century over pre-industrial times.
Temperatures like these will make some cities unlivable — and avoiding that fate is one reason why cities around the world are innovating within their public realms in ways that respond to rising temperatures now and prepare for an even hotter future. Today we feature five global cities doing just that.
Seville, Spain: Using shade and water in old and new ways
Seville has always had hot days. The Spanish city regularly experiences summer temperatures above 104°F, contributing to a culture of staying inside during the day and coming out for late evening dinners and festivals that start at 10 p.m.
But rising temperatures — combined with changes in culture associated with computer use, social media and a reduction in public socializing — are causing concerns about losing this lively culture of outdoor nightlife. Scientists predict that, within the next 10 years, Seville will experience multi-day heat waves with temperatures rising above 122°F.
To adapt, the city is using a mix of strategies that bring together modern knowledge and historical techniques. Shade figures prominently. Photos from as far back as the 1940s show large awnings shading Seville’s streets in popular parts of town, protecting people from direct sunlight and contributing to cooling. Recently, awnings have been installed at more public places, including taxi stops, schools, playgrounds and hospital entrances. The city is installing public fountains, planting 5,000 trees annually and prioritizing construction materials that reflect heat.
Seville has also built CartujaQanat — an innovative, $5.1 million pilot project that is expected to reduce average temperatures by 18°F on one street. Inspired by the 1,000-year-old Persian technology known as qanats, CartujaQanat carries cool water through underground canals, and vertical vents release the coolness upwards, reducing the street-level temperature. Powered by renewable energy, the system also pumps water to help cool a building and outdoor benches. The same technology will be used in “comfort rooms” along a main avenue, giving people a break from the heat.
Seoul, South Korea: Citywide public gardens and greening
Seoul is working toward a comprehensive, citywide plan to address climate issues — and a big focus is gardens and greening. In 2023, the city announced its goal to create gardens in 1,007 locations by 2026 by transforming unused lands like roads and empty squares into places for people to rest and building gardens everywhere from public parks to medical facilities to rooftops.
The gardens will produce many benefits for Seoul’s aging population, from reducing particulate dust levels and average daily temperatures to decreasing stress and loneliness. Studies show people who spend time in a garden at least once a week experience stress reductions of over 60 percent. By providing access to a green space within a five-minute walk of most people’s homes, the new gardens will encourage people to spend time in nature. The gardens also create jobs for both installation and maintenance.
In addition to the $212 million investment in outdoor gardens, Seoul is also building greenways, walking trails and walking paths that connect to subway stations. These public green spaces combat rising temperatures, provide shade and encourage people to get outside.
Masdar City, United Arab Emirates: Cooling with the built environment
In the United Arab Emirates and other countries in the Persian Gulf, cooling cities can be a matter of life or death. Temperatures frequently surpass 110°F and sometimes climb above 120°F. Extremely hot days will become more frequent and even hotter as the planet warms.
One response of the oil-rich UAE: build, from scratch, the world’s first zero-carbon, zero-waste city. Although Masdar City, the futuristic zone on the outskirts of Abu Dhabi, has not lived up to that promise in many ways, elements of its design provide insight for other cities looking for cooling solutions.
Even in blazing temperatures as high as 110°F, people can walk outside in Masdar City. This is because tall buildings cast cooling shadows on its narrow, vehicle-free streets. Combined with trees, fountains and breezes, these walkable alleys remain as much as 18°F cooler than areas exposed to the sun. In addition, inspired by other countries in the region, parts of Masdar City are elevated to take advantage of the stronger winds that exist on higher grounds.
Masdar City provides a contrast to other urban areas in the UAE. In central Abu Dhabi, for example, skyscrapers line eight- and 10-lane avenues dominated by cars and lacking shade. Walking is unpleasant and even unsafe, especially in summer.
Further, Masdar City’s buildings — and newer buildings in other parts of the UAE, such as Dubai — are designed to be sustainable and livable and to use less energy for cooling. Architects have reintroduced construction techniques, including some pioneered by ancient Persians, that respond to the environment. These include orienting buildings away from the sun, accounting for wind patterns to allow for natural ventilation, reducing the use of glass and, inspired by traditional Islamic architecture, incorporating shade, courtyards and terraces. Many structures recirculate air inside buildings, reducing the need for air conditioning. And design features such as opaque walls and extra-thick windows prevent buildings from getting hot in the first place.
All of this represents a major shift away from steel, concrete and air conditioning. Other cities are taking notice — and these ideas are spreading across the region and the world.
Freetown, Sierra Leone: Claiming cooling as a priority with a chief heat officer
Africa accounts for only 2–3% of the world’s emissions, but countries and cities in North Africa face some of the most severe heat-related risks. This is true of Freetown, Sierra Leone, where the average temperature — including at night — is expected to be around 81°F for 50% of the year by 2050. To help prevent such a future, Freetown became one of just a handful of places in the world — and the first in Africa — to create a role dedicated to finding innovative and impactful ways to cool people and places in the city.
Eugenia Kargbo became Freetown’s chief heat officer in 2021. Kargbo grew up in Freetown in the 1990s, before the city sprawled into the lush forests and beaches that once surrounded it. Today, up to 60% of Freetown’s 1.2 million people live in makeshift, corrugated iron housing, and few homes have air conditioning. Along with heat waves that last almost all year long, the city is threatened by deadly landslides and floods.
Kargbo’s goal is to make Freetown greener and more livable, and she is taking steps toward a more resilient future. Her office has begun installing plexiglass canopies to shade vendors, many of whom are women, in the city’s open-air markets. New public gardens provide places for residents to enjoy nature and get a break from the heat. And Kargbo is shepherding the “Freetown the Treetown” initiative, planting over 560,000 trees and creating 550 short-term jobs while boosting awareness about the benefits of trees and protecting the environment. The tree planting initiative goes hand in hand with the city’s work to build green corridors in vulnerable communities. White roofs that reflect heat, public water fountains and many more trees and green spaces are among Kargbo’s future plans.
But she also faces hurdles. Sierra Leone is one of the world’s poorest countries, so ambitious initiatives are often out of reach. Funding challenges have slowed the tree-planting effort, and at least 100,000 of the planted trees have died. A fraught relationship with a government led by the opposition party has created stumbling blocks, as reported by The New York Times. These challenges highlight the importance of political support, consistent funding and ongoing maintenance in combating heat.
Paris, France: Layered strategies and creative approaches to water and greening
France’s largest city is transforming through Paris Adapts, a multifaceted plan that brings together tree planting, shade, asphalt removal, urban agriculture, outdoor recreation, building cooling and other strategies to green and cool the city’s public spaces and mitigate rising temperatures.
One focus of the plan is schools and the areas around them. “Oasis courtyards” at schools and colleges will feature cooling amenities like shade, fountains, furniture to rest on and climate-resistant plantings. Students participate in the design process, and, in addition to protecting kids from the heat, these courtyards open to the public on the weekends, creating new public spaces for all to enjoy. Streets near preschools and elementary schools are also being transformed: over 200 such streets across the city are being turned into green, car-free zones, making it safer and more comfortable for Paris kids to walk to school.
Through Paris’s robust tree plan, the city aims to plant 170,000 new trees by 2026 while maintaining and monitoring 500,000 existing trees in urban areas and urban forests. The new trees will provide shade, beauty and improve the air quality in a wide range of places, including streets, green spaces, forests and cemeteries. The city is prioritizing diverse, heat-adaptive species that are native to the region. They are also employing technology to monitor individual trees’ health. Since 2014, each tree has been assigned a “computer identity card” that sends information on maintenance and health to a centralized database.
Parisian residents and visitors can cool off in the pools, shady areas and recreational places along the River Seine and at public fountains around the city. The Paris Plages (beaches) draw people in for socializing and a break from the heat with cool lawns, sun umbrellas, cultural and sporting activities and swimming. At the various Plages along the riverfront, there are swimming opportunities for swimmers of all abilities, refreshment vendors, ice cream sellers and even a summer beach resort. To prepare for the 2024 Olympic Games, Paris installed “Mât Source” fountains that serve two functions: they are both drinking fountains and misters. These public fountains are accessible to all and provide easy access to cooling during the city’s hot summers.
As cities innovate, there’s hope to mitigate rising temperatures
The forecast predicts ever-hotter temperatures in cities worldwide — but creative, impactful solutions can protect people from heat and shift the most dire projections for warming.
These five cities are not alone in providing actionable, publicly accessible solutions, but more cities need to follow their lead and develop solutions of their own. This collective work is essential for creating livable cities and keeping people safe as our world warms.
Reimagining the Civic Commons is a collaboration of The JPB Foundation, the John S. and James L. Knight Foundation, The Kresge Foundation, William Penn Foundation, and local partners.
