May 31, 2022 - Energy & Environment

For cities, staying cool is the hot new thing

Illustration of a building in the shape of a sweating popsicle
Illustration: Sarah Grillo/Axios

As summer kicks off, a small but growing number of cities are getting serious about heat mitigation — but experts say too many leaders are still ignoring the problem.

Why it matters: Scientific studies have documented a dramatic rise in heat-related deaths, and there’s broad agreement that cities need to adopt comprehensive cooling strategies to maintain public health.

  • That’s especially urgent as climate change contributes to extreme events like last year’s heat wave in the Pacific Northwest, which resulted in an estimated 1,400-plus deaths.
  • But most cities are only at the planning stages or conducting small-scale pilots — if they're addressing the issue at all.

Where it stands: There's broad acknowledgment that rising temperatures are making urban centers less livable, but many cities lack the budget or political support to meaningfully tackle the problem.

  • Only three major U.S. metro areas — Phoenix, Los Angeles and Miami/Dade County — have established "chief heat officers."
  • "There's a huge number of small- and mid-sized cities that really don't have anybody thinking about sustainability and climate in a fully comprehensive or truly integrated way," says Rushad Nanavatty, managing director of RMI, a clean energy nonprofit.

Driving the news: Cities have been gearing up for this summer's heat, trying in particular to use cooling methods other than air conditioning, which is energy-and-emissions intensive.

But a new United Nations Environment Programme (UNEP) urban heat mitigation handbook found a "vast gap between the stated ambition and what was actually happening on the ground," Nanavatty, one of the authors, told Axios.

  • "We haven't gotten to a point — and this is what we're working on — where climate logic is fully embedded into a city's operations."

The big picture: Cities have been warming at twice the global average because of the "urban heat island" effect, whereby buildings and pavement trap heat that might have otherwise been diffused by foliage.

  • Low-income people tend to suffer the most, since they're more likely to lack A/C, work outdoors and live near industrial facilities.
  • A 2021 study found that "in areas with higher rates of poverty, temperatures can be as much as 4 degrees Celsius, or 7 degrees Fahrenheit, warmer during the summer months when compared with richer neighborhoods," per NPR.

Details: Phoenix — one of the hottest U.S. cities — has been particularly proactive in tackling the problem.

  • Its "Cool Pavement Program," which involved painting a gray coating on streets, reduced roadway temperatures by 10.5 to 12 degrees Fahrenheit, per Scientific American.
  • The city aims to build 100 "Cool Corridors" by 2030 "in shade-starved zones with high pedestrian traffic," the Arizona Republic reports.
  • "This is life and death infrastructure for cities,” Jad Daley, CEO of American Forests — which is supporting the Cool Corridor initiative — told the Arizona Republic. "We ought to be investing in it, as a country, like it matters."

Among smaller cities, Chelsea, Massachusetts, a low-income neighbor of Boston, has a noteworthy pilot involving a single city block:

  • "The Cool Block project is loading the area with pretty much every heat-fighting tool in use around the country," according to WBUR.
  • "There are 47 new elm, crabapple, cherry and hawthorn trees. Sidewalks are being ripped up to add planters, porous pavers or white concrete. Dark asphalt will be replaced with gray."

What's next: A new tool called the Heat Action Platform, which city leaders can use to develop an extreme heat road map, was unveiled last week at the World Economic Forum in Davos, Switzerland.

  • "A big positive is that cooling as an issue is really coming on the radar of people in a way that it didn’t necessarily in the past," says Sneha Sachar of RMI.
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