It’s Too Hot in the City

As you drive through the West End neighborhood of Richmond, Va., you might see ornate university buildings, enormous houses in quiet neighborhoods, and stretches of sit-down restaurants and storefronts. But as you move into the downtown area farther east, skyscrapers and tall apartment buildings begin to dominate the landscape. There is much less green space, and the area has a substantial homeless population.

In 2017, with a burgeoning awareness about environmental justice, the Commonwealth of Virginia began to pay attention to how socioeconomic status influenced the most important aspects of the lives of city dwellers, things like clean water and air quality, and formed the Virginia Council on Environmental Justice. Around the same time, researchers at the University of Richmond and the Science Museum of Virginia turned their attention to how heat relates to demographics.

Prompted by similar work taking place across the country, the researchers undertook a study, published in the journal Sustainability in February, to measure temperatures in different city neighborhoods. They rounded up volunteers to collect data with sensors, and found that socioeconomically disadvantaged communities suffered from extreme heat and its health effects, such as heatstroke and heat exhaustion, more frequently than other communities.

Scientists call what is happening in poorly planned neighborhoods the “urban heat island effect.” The islands mainly affect people who live with less green space and fewer large bodies of water like lakes, both of which absorb heat and cool off residents. Daytime temperatures in urban areas are about 1 to 7 degrees Fahrenheit higher than those in outlying areas, and nighttime temperatures are about 2 to 5 degrees higher, according to the Environmental Protection Agency.

Researcher Kelly Saverino found in a separate, 2020 study a link between excessive heat and air quality, something she said is becoming more well known and better studied in the field. This is key because air quality ties into a host of health conditions, especially respiratory conditions like asthma.

With so much at stake, it is critical to not only learn more about the science of urban heat islands, but also to grapple with the human element of the climate crisis. As with many parts of the environmental movement, heat islands are intricately linked to social justice.

Saverino told me about historical redlining and zoning restrictions, some originating more than a century ago, that stratified neighborhoods in Richmond. People who couldn’t afford single-family homes were pushed out of wealthier neighborhoods, leading to segregation. The West End, in effect, became suburban, with more greenery and houses spread farther apart than in the densely populated East End neighborhood, which has more concrete and other materials that hold heat.

“It’s still having a lasting impact today,” Saverino said of the old redistricting. “It still creates segregation and disproportionate harm to half of Richmond’s population.”

In the past year, an abundance of research has emerged about the deadly effects of the islands globally. One study in China forecasted that the number of Chinese heat-related deaths will increase somewhere between 7,000 and 17,000 by 2050. A 2020 study looked at the mitigation effects of air-conditioning in Canada, Spain, Japan, and the United States. The researchers did find an association between increased air-conditioning and decreased heat-related deaths, but said that “other factors have played an equal or more important role in increasing the resilience of populations” — things like demographics, socioeconomics, and infrastructure.

So the answer to urban heat islands, unfortunately, is not as simple as just installing more air-conditioning in buildings. There are crucial social components that need to be addressed to bring down temperatures.

Many homeless people don’t have access to housing, air-conditioned or not. Non-White urban areas are less likely than White parts of cities to have parks, and even if they do have a healthy supply, the size of them is half that of those in White areas, a 2020 study found. Living in hotter areas can increase energy costs, adding financial stress to households. A June study in Hong Kong correlated poor indoor ventilation with higher mortality of all kinds. Specifically, asthma-related deaths were significantly higher in places with less than optimal ventilation — aka most often lower-income housing. Researchers in Beijing found that lower-rise buildings spaced close together worsened the urban heat island effect.

There are solutions, however. Organizations like the Chesapeake Bay Foundation in Richmond have begun planting hundreds of trees in the hottest neighborhoods, even giving away free trees to residents in October. And while the West End and East End divide might seem stark, no matter which side of the city you’re on, you always have access to the James River, which runs through the city — a universal resource for Richmond residents, no matter their socioeconomic status.

Eradicating urban heat islands means thinking big as the climate crisis intensifies, and that translates to reimagining urban planning and landscaping, as well as understanding how people are pushed into living in poor conditions — and actually doing something about it.