Most Major U.S. Cities Underprepared for Rising Temperatures

For instance, many plans looked at heat through a “hazard” lens, focusing on extreme events like triple-digit heat waves. When identifying the issue as a crisis akin to a hurricane or flood, the solutions often fit into a disaster response–style approach — like text alert systems and air-conditioned public cooling centers.

Other plans defined the issue in terms of the “urban heat island effect,” a phenomenon whereby cities — because of their heat-absorbing infrastructure, like asphalt — become and remain hotter than surrounding rural areas. In framing the issue as a land-use problem, these plans often focused on physical ways to cool cities. Adding more trees was the most common intervention, while sun-reflecting cool roofs and vegetation were also mentioned.

However, the study found that these two approaches to heat governance rarely overlapped. And while each approach has its benefits, such narrow framings don’t get at the full issue, the researchers emphasized.

“If cities are not painting a complete picture of heat — how chronic it is, and its disparate impacts on the ground — we’re not going to be able to fully protect residents, and we could end up exacerbating existing social and environmental injustices,” said co-author Emma French, a doctoral student in urban planning at the UCLA Luskin School of Public Affairs.

Even some seemingly obvious solutions, such as providing outdoor shade for residents, received short shrift in planning documents, noted co-author Ariane Middel, an assistant professor at Arizona State University. “Shade is the most effective way to protect pedestrians from exposure to sunlight, but few cities mentioned shade in their plans.”

Further, heat was only identified as an equity issue one-third of the time, despite a growing body of evidence that urban communities of color are disproportionately affected by rising temperatures as a result of longstanding social, structural and health-related inequities. Cities that don’t address this disparity can expect to see increasingly adverse implications down the road, the researchers stressed.

Among cities with more robust preparations for heat, membership in environmental networks like the National League of Cities and the Urban Sustainability Directors Network was more common. These groups bring together sustainability practitioners from across the country, and their broader governance structures can offer opportunities to share best practices.

“Peer-to-peer knowledge exchange through networks that connect large and small communities is going to be essential to implementing the most effective solutions as quickly as possible,” said co-author David Hondula, an associate professor at Arizona State University and director of the Office of Heat Response and Mitigation for Phoenix.

Read more about the Luskin Center for Innovation’s heat-related research and policy recommendations in their Adapting to Heat in California (PDF) report and Protecting Californians From Deadly Heat (PDF) policy brief.