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How cities can protect people from extreme heat

The 2021 heat dome in Washington contributed to 441 deaths. It also made clear several ways to avoid that same outcome in future heat waves.

How cities can protect people from extreme heat
[Source photo: Bryce Carithers/Pexels; Raw Pixel]

The heat dome that descended upon the Pacific Northwest in late June 2021 met a population radically unprepared for it.

Almost two-thirds of households earning $50,000 or less and 70% of rented houses in Washington’s King, Pierce, and Snohomish counties had no air-conditioning. In Spokane, nearly one-quarter of survey respondents didn’t have in-home air-conditioning, and among those who did, one in five faced significant (often financial) barriers to using it.

Imagine having no way to cool your home as temperatures spiked to 108 degrees Fahrenheit (43 Celsius), and 120 F (49 C) in some places. People in urban heat islands—areas with few trees and lots of asphalt and concrete that can absorb and radiate heat—saw temperatures as much as 14 F (7.8 C) higher than that.

Extreme heat disasters like this are becoming increasingly common in regions where high heat used to be rare. Blackouts during severe heat waves can also leave residents who believe they are protected because they have in-home air conditioners at unexpected risk. To prepare, cities, neighborhoods, companies, and individuals can take steps now to reduce the harm.

In a new report, written with colleagues at universities and the Washington State Department of Health and released ahead of the two-year anniversary of the heat wave, we show how municipal planning agencies, parks departments, local health agencies, community-based organizations like churches and nonprofits, multiple state agencies, hospitals, public health professionals, and emergency response personnel, as well as individuals and families, can play a vital role in reducing risk.

The 2021 heat dome was Washington’s deadliest weather disaster on record. It contributed to 441 deaths in the state from June 27 to July 3, our research shows. Medical systems were overwhelmed.

There are numerous ways to avoid this deadly of an outcome in the future. Many emerge from thinking about extreme heat as long-term risk reduction, not just short-term emergency response.

DESIGNING ENVIRONMENTS FOR COOLING

Greening the urban environment can reduce heat exposure and save lives. For example, planting trees and building shade structures where people are most exposed to heat can provide local relief from extreme temperatures. That includes providing shade at buildings without air-conditioning and at exposed public spaces such as bus stops and parks.

Planting rooftops with vegetation, known as green roofs, or painting them white so they reflect heat rather than absorb it, can also lower roof temperatures by tens of degrees. Used widely, they can reduce an entire neighborhood’s heat island effect by several degrees.

An illustration showing a cross-section of a region, with a city and rural areas, and two chart lines showing day and night temperatures. The temps rise over areas with lots of concrete and asphalt, particularly dense areas that hold the heat.
Developed areas tend to heat up more than natural landscapes, such as parks. That can increase heat stress on humans. [Climate Impacts Group/University of Washington, adapted from EPA]

Efforts like these, along with tree-planting campaigns in public parks and rights of way, and ordinances requiring shade trees for parking lots and private development projects, can transform the urban heat landscape.

REACHING VULNERABLE PEOPLE

When heat waves are coming, culturally nuanced outreach efforts focused on the most vulnerable populations—and involving sources they trust—can save lives.

Government heat advisories in traditional media like radio, newspapers, TV, and the internet have been shown to have limited success in changing people’s behavior. In the 2022 Spokane survey, 88% of respondents indicated they were unlikely to leave their home during an extreme heat event to go to a cooling center, for example. The reasons varied, including misperception of personal risk, fear of leaving homes unoccupied, not wanting to leave pets behind, and mistrust of government.

Culturally specific resources led by community-based organizations can get around the government trust issue and can be tailored to the local population.

That might mean opening cooling centers in churches or common community gathering places and launching heat-awareness campaigns driven by trusted community messengers. New York City developed a door-to-door wellness check program that uses neighborhood volunteers to check on elderly and other at-risk residents.

Under this model, churches, libraries, community centers, and community nonprofits take center stage, supported with resources from local and state governments. Baltimore developed more than a dozen “resiliency hubs” using this model to provide water, cooling, power for charging devices, and other support.

Community-based organizations can also direct energy assistance to lower-income community members. In Spokane, one community organization created a “cooling fund” to provide portable air conditioners to those who cannot afford one.

Our report lays out many other strategies to achieve long-term heat risk reduction.

LANDLORDS, EMPLOYERS, AND UTILITIES HAVE A ROLE

Addressing extreme heat over the long term requires the participation of many other groups not tasked with protecting public health.

For example, landlords of multifamily housing and rental homes have an important role to play. After the 2021 heat wave, Oregon passed a law prohibiting landlords from restricting tenants’ ability to install window air conditioners.

Employers of people who work outdoors, or indoors in buildings without air-conditioning, can protect workers by allowing more breaks, providing shade and water, and adjusting work hours to avoid heat exposure—although concerns persist about rule enforcement and reduced pay.

Utilities can make a difference by ensuring the power stays on during high-demand periods, particularly in vulnerable neighborhoods, and working with communities to reduce costs for vulnerable people that may prevent them from using air-conditioning.

Ultimately, reducing extreme heat vulnerability through multiple strategies is crucial because lives are at stake.

COORDINATION IS ESSENTIAL

Extreme heat waves are forecast to occur more frequently across the globe as greenhouse gas emissions continue to warm the climate. From 1971 to 2021, Washington state experienced an average of three extreme heat days per year. By the 2050s, climate models project that will rise to between 17 and 30 extreme heat days per year—a fivefold increase.

Five maps show observed temperature change and much higher changes by mid and late century, particularly with high-emissions scenarios.
Annual average temperatures are projected to increase, with proportionally greater changes at higher latitudes. The top map shows observed temperature changes from 1986 to 2016 relative to 1901 to 1960. The lower maps show projected changes for mid-century (2036 to 2065) and late century (2070 to 2099) depending on high and low greenhouse gas emissions. [Fourth National Climate Assessment/NOAA NCEI/CICS-NC]

In the end, saving lives from extreme heat is a complicated challenge requiring coordination across multiple levels of government, agencies, and the civic and private sectors.

Some cities, including Phoenix, are experimenting with heat offices tasked with this coordination. But individuals have an important role to play as well.

In addition to knowing how to protect themselves, their loved ones, and their neighbors, individuals can add their voices to the rising chorus calling on all levels of government and the private and civic sectors to take urgent steps to reduce heat risk.

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ABOUT THE AUTHOR

Jason Vogel is the interim director at the University of Washington Climate Impacts Group. Brian G. Henning is a professor of philosophy and environmental studies at Gonzaga University. More

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