A new urban map from Climate Central shows that almost 80,000 people in the Denver area live where the heat index is more than 9 degrees hotter due to the Urban Heat Island Effect.
Census data studied by analysts at Climate Central found that almost half of Denver residents are in tracts with at least an eight-degree temperature increase attributable to the built environment, and in the worst municipality, Westwood, there was a temperature increase of 10.14 degrees in the past year.
“Ultimately, we live in a warming world,” said Climate Central Director of Communications Peter Girard. “And as temperatures climb, no matter what we do to help people in the immediate time, they will be exposed to hotter and hotter temperatures in their neighborhoods.”
Girard emphasized the urgency with which the climate crisis is affecting our cities. To better help conceptualize the issue at hand, climate science experts at Climate Central developed a U.S. Climate Shift Index Map. This tool can be used to track the ratio of how common, or likely, a temperature is in today’s altered climate versus how common it would be without human-caused climate change.
On July 26, the Climate Shift Index indicated a level of five. “This is the maximum influence of climate change that our scale can show. It means that the temperatures you’re seeing today in Denver were made five times more likely by climate change,” Girard said. “That is a very confident signal that climate change is making today’s temperature higher than it otherwise would be.”
Denver is one of Colorado’s hottest cities, and is particularly affected by the “heat island effect.” Heat islands are urban areas that experience higher temperatures due to tall buildings and roads absorbing and re-emitting the sun’s heat. The phenomenon is causing major issues for people in recent weeks, and the rising temperatures disproportionately affect those experiencing poverty. According to Kim Yuan-Farrell, executive director of The Park People, a Denver nonprofit that works with urban communities to plant trees and improve public parks to help mitigate the effects of climate change, it is tricky to get the balance right.
“It’s such a struggle trying to balance the needs of the built environment and people’s needs related to housing and the impacts that has on the environment. Denver has been densifying and experiencing more infill, and those paved surfaces or hard, heat-absorbing surfaces definitely increase the urban heat island,” she said.
According to Yuan-Farrell when it comes to future city planning, more green space, more canopy coverings, and more robust, healthy urban forests need to be considered.
“For many decades now, we’ve had a focus on low canopy, which generally correlates to low and moderate-income neighborhoods, where there are high concentrations of communities of color,” she said. “And, just like many other midsize and large cities, there’s that correlation between low canopy, urban heat and communities of color and low-income communities.”
Access to free local public parks, like Argo Park in Globeville, especially ones that have a splash area or pool for families with kids on hot summer days, are especially important.
“Our neighborhood parks and our trees throughout our parks and other open green spaces really are such a critical, natural solution to many of the rising heat and extreme heat events that we have,” Yuan-Farrell said. “Homes can trap heat and act like little mini-greenhouses. Outdoor spaces, when they’re shaded, and when there’s nearby shade, can be significantly cooler. So it’s such an important natural resource for residents to have nearby.”
As far as solutions, Yuan-Farrell said The Park People offer free and low-cost trees for Denver residents to plant on public right-of-ways and private property. The group is also working to change roofs to lighter colors or reflective surfaces, even going so far as to plant rooftop gardens to subdue the heat. Replacing sidewalks and pavement with lighter-color materials can also “dramatically change the profile within urban heat islands.” Cities with large green spaces and parks, like Central Park in New York City, often have lower Urban Heat Island Effects. But Girard said Denver doesn’t need to go demolishing large swaths of buildings anytime soon.
“You don’t need a central park in the middle of your city to address these issues,” Girard said. “Even smaller attention to planting grass and removing permeable and impermeable surfaces can change the urban heat island effect in a neighborhood.”
But even with those adjustments, temperatures can only be manipulated so much.
“In some cases, cities will always be warmer, the built environment and cities will always be warmer than in places that don’t have those characteristics,” Yuan-Farrell said.
Girard recognized it can be hard to get away from the pessimism about climate change and avoid apocalypse fatigue. Although there is urgency to the matter, Girard said, there is progress being made. Emissions are being reduced and renewable energy is becoming a bigger industry across the U.S. and the world.
“It’s not entirely gloom and doom and the world is going to end, but God knows there’s work to do,” Girard said.