Building Cooler Cities

Snapshot of Philadelphia's plan to add green infrastructure throughout the city. Credit: Philadelphia Water Department

I was in Paris last week where temperatures reached 97 degrees Fahrenheit, and at one point had a heat index of 105 degrees. My husband and I did our best to stay in the shade and cool off indoors while exploring the city, but we were miserable until the temperature broke. Our love for the efficiency of the Parisian metro system waned when we had to ride trains that didn’t have air conditioning. Even our accommodations for the first two days only had a rotating fan. Our Airbnb host said, “This is Paris. There’s no air conditioning. What did you expect?”

Well, sir, I expect for businesses, and dwellings and public transport to have air conditioning, or a fan big enough to blow my edges away. Sitting on a broken down train for 30 minutes when it is 100 degrees is not part of my ministry. (Nor is walking through the halls of Versailles with no air circulating. But that’s another story.)

More people die each year from extreme heat than all other natural disasters combined.

Heat-related deaths and illnesses are preventable, but hundreds of people will die this year due to heat exposure and humidity. According to the Centers for Disease Control and Prevention, approximately 618 people are killed in the U.S. every year due to extreme heat. By the summer of 2030, climate change could cause an additional 11,000 heat-related deaths in the U.S.

Those of us living in cities are at a higher risk of heat-related illnesses due to the urban heat island effect, where manmade surfaces and human activity causes cities to be warmer than surrounding non-urban and rural areas. Not only are roof and pavement surfaces often 50 – 90 degrees hotter than the surrounding air, elevated temperatures in heat islands can increase levels of air pollution and impair water quality.

Children, the elderly, individuals with chronic illnesses, people working outdoors and low-income families in poor housing conditions are most vulnerable to temperature extremes. Race and poverty also contributes to more non-white Americans (primarily black Americans) dying from heat-related causes than white Americans. Poorer neighborhoods tend to have less tree cover and more asphalt compared to affluent neighborhoods. Studies also show they have less access to air conditioned facilities.

Summer has just arrived and Phoenix has already set daily records with temperatures reaching 120 degrees, causing a surge of heat emergencies. Heat exposure is said to be the possible cause of 12 deaths in the metro Phoenix area last week. The heatwave is also responsible for the deaths of another 18 people in other parts of Arizona, Nevada and California.

We’re starting to see milder winters, prolonged heat waves and more days with elevated temperatures due to a warming climate. Without additional adaptation, we will see an increase in heat-related deaths, illnesses and hospital visits, especially in metropolitan areas. We’ll also continue to add higher concentrations of greenhouses gases due to high electricity demands during the summer months.

Current support services during heat waves include providing water, air conditioning and access to cooling centers, but cities must do a better job of implementing green infrastructure as part of its urban planning. More local governments need to take steps to reduce energy demands and help residents reduce their vulnerability to heat with cool or green roofs, cool pavements, trees and vegetation.

And we need to put vulnerable populations first. Installing green roofs on new buildings in gentrified areas only serve a subgroup of the population that generally aren’t categorized as being vulnerable to extreme temperatures. Cool roofs should be added in low-income housing communities. Something as simple as planting trees along the streets in high-poverty neighborhoods can make walking to the grocery store or waiting for public transit more bearable.
Additionally, green infrastructure reduces stormwater runoff and noise pollution, improves air and water quality, decreases crime, enhances community aesthetics and creates community cohesion.

Creating programs that provides funding for residents to invest in greening their neighborhoods are cooling measures that need to be considered to reduce the risk of heat emergencies and deaths. We need cities to reduce the burden for those who are most susceptible to extreme temperatures, and green infrastructure is the next viable solution.

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