Wind Maps and Rice Terraces: How Cities Adapt to Climate Change

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Urban areas sit at a critical crossroads of climate change. Cities are known for their significant contribution to global greenhouse gas emissions, unsustainable sprawl and resource consumption. Yet their locations — often on coasts or floodplains — and tendency to trap heat make them especially vulnerable to climate impacts. 

More than half of the people on the planet live in cities, and that number is rising fast. The worsening effects of climate change and more people moving in, including many already displaced by climate-related disasters, can increase existing social and economic inequalities. 

All of this reduces urban livability, making adaptation and mitigation vital for the safety of city residents and the city's future. This position pushes urban areas to become incubators for innovative climate solutions. Cities around the world are finding new ways to adapt to their unique challenges while reducing their overall impact. 

For climate adaptation to be successful, cities should focus on two categories: systemic-resilience actions and hazard-specific actions, according to a report from the consulting firm McKinsey & Co. and C40 Cities, a global network of mayors addressing climate change. Systemic-resilience actions broadly improve a city’s ability to adapt and decrease risks, like considering climate risk in urban planning or building early warning systems. 

Using artificial intelligence-powered digital twins to assess risks and test whether sustainable development plans are effective is a systemic-resilience approach gaining traction globally. These twins are accurate virtual models of a city that use real-time data to simulate scenarios and offer predictions. Singapore uses a digital twin to plan green infrastructure projects like increasing shade by planting trees, as TriplePundit recently reported. Similarly, Mendoza, Argentina, uses the same software to keep track of the health of its 1 million trees and plan proactive maintenance. 

Enhancing the programs that finance adaptation projects is another systemic-resilience action cities can take. For example, Philadelphia’s Build to Last program recently received city funding for the first time. It offers repairs and sustainable upgrades for low-income homeowners to “future-proof” their homes with upgrades like heat pumps that cool homes during heat waves instead of air conditioning to reduce emissions and lower utility bills. 

The Philadelphia program steps closer to the second part of a successful adaptation plan, hazard-specific actions. These approaches focus on addressing a distinct problem, like making water infrastructure more efficient amid a drought or building flood-resilient buildings. 

The architects across Asia taking inspiration from traditional rice farms to prevent flooding are one example. In Bangkok, the roof of Thammasat University mimics rice terraces, a farming practice that’s thousands of years old. Small ponds stacked like a staircase allow water to cascade down and collect on the roof. The roof is actually used to grow rice, so when it’s dry, the university uses clean energy to circulate the water and irrigate the crops. It’s estimated to slow the excess rainwater that flows to the ground by 20 times compared to a concrete roof and it keeps the building several degrees cooler in the summer, BBC reports. 

Green roofs like Thammasat University’s are a part of a larger flood management concept gaining traction called “sponge cities.” Developed by Kongjian Yu, a landscape architect in China, this method calls for creating more nature-based areas to slow and absorb excess water instead of diverting it with pipes and concrete. 

Though rooftop gardens are also a part of Frankfurt’s plans to stay cool, focusing on that alone isn’t an effective way to address extreme heat — its main problem as one of the hottest cities in Germany. That’s why individualized, hazard-specific approaches are important. Frankfurt worked with experts to develop a map of the wind corridors that keep the city cool. Now, the city uses that information to build green spaces that link air corridors to keep air moving and keep houses and skyscrapers out of the way, Bloomberg reports.

But cities are complex environments. Even those facing the same problem likely need to take different approaches. While Frankfurt focuses primarily on greenery and air currents to keep neighborhoods from heating up, cities like Los Angeles are trying cool pavement coatings. Applied like paint, the coatings decrease the temperature of the ground and the air around it by reflecting the sun’s rays, as 3p previously reported. When applied on a park in one of the hottest neighborhoods in the city, the coated pavement measured up to 14 degrees Fahrenheit cooler than non-coated areas, and residents said they noticed the difference. 

The downside to this often necessary, individualized approach is incredibly slow progress. I isolated the most pressing issues in the locations above, but most cities face several climate impacts simultaneously. And though adaptation methods can apply to many different cities, they typically need to be altered based on the location’s unique circumstances. It’s rarely a copy-and-paste process. 

Still, collaboration is happening. The group of mayors that make up C40 cities, for example, are sharing knowledge with each other and the public as they work to halve their cities’ emissions. The United States Environmental Protection Agency also employs regional climate change adaptation coordinators who synchronize efforts across the country. 

The key is sharing information to provide a starting point. From there, the solution can be modified to meet specific needs based on local knowledge and input from the residents most vulnerable to climate impacts. Why waste time recreating a recipe that already exists from scratch?  

Dive deeper into this solution: 
●    He’s Got a Plan for Cities That Flood: Stop Fighting the Water, The New York Times
●    As temperatures in India break records, ancient terracotta air coolers are helping fight extreme heat, BBC
●    Skyscrapers Can Make a Statement About Sustainable Design, TriplePundit
●    Podcast: Keeping Cities Cool in a Warmer Future, The Wall Street Journal