The Pressing Need to Improve Urban Responses to Extreme Heat

August 25, 2020

Heat is the leading weather-related killer in the nation, causing hundreds of deaths each year. Exposure to heat can have numerous health impacts, such as heat cramps, heat exhaustion, heat stroke, and can exacerbate other health conditions. As climate change advances, extreme heat will become increasingly frequent and severe across the world, causing more adverse health impacts.

During my research as an EESI intern during the summer of 2019, I encountered projections of a dangerously hot future. If we continue on our current emissions path, the late-century United States will experience, on average, twice as many days per year with a heat index above 90ºF, four times as many days per year with a heat index above 100ºF, and eight times as many days per year with a heat index above 105ºF, compared with the historical baseline.

Troubled by these predictions, I began searching for a solution—how can we protect our future from a devastating increase in extreme heat? The answer is not surprising: we must drastically cut greenhouse gas emissions to avoid the worst possibilities of future heat—aggressive measures are the only solution. Rapidly cutting emissions to contain warming within 2°C (3.6°F) above pre-industrial levels would spare about 125 million people nationwide from a month or more of heat index conditions above 105°, compared with our current emissions track.

But even if we rapidly mitigate global emissions, some damage has already been done and temperatures will still rise from historic levels. This is where climate adaptation comes in: adjusting to life in a changing climate in an effort to reduce exposure and vulnerability to harmful climate impacts. In the case of extreme heat, cities are at the forefront of the emergency response systems that help residents adapt to dangerous conditions. Many U.S. cities use cooling centers to provide safe, cool spaces to vulnerable populations.

This year, I wrote my undergraduate thesis on urban adaptations to extreme heat, focusing on cooling centers in Phoenix, Chicago, and New York City—three cities with vastly different historical climates. Phoenix, Chicago, and New York each have multi-faceted plans to prepare for extreme heat, but these plans fail to protect numerous people each year. Why have city-wide cooling centers been inadequate in preventing heat-related death?

I analyzed the accessibility of cooling centers on three dimensions (physical proximity, facility type, and operating hours) to determine if they were accessible to vulnerable populations. I conducted a proximity analysis based on a half-mile radius around each cooling center (which I assumed to be an accessible walking distance for most people), and calculated significant populations that live out of range of a cooling center in each city. The result: at least 76.9 percent of the Phoenix population, 46.7 percent of the Chicago population, and 19.4 percent of the New York population live more than half a mile away from their nearest cooling center. Many neighborhoods with high vulnerability to heat (i.e., neighborhoods with sparse green space, large elderly populations, or high rates of poverty) were far from any cooling center. Furthermore, most cooling centers operate during business hours and leave crucial nighttime and weekend hours unprotected. My findings suggest that heat-related health impacts will worsen over time unless cities make cooling centers more accessible, particularly for vulnerable populations.

However, cooling centers are not the only policy choice for heat adaptation, and might not be the best. While cooling centers are immediately beneficial to public health, their use of air-conditioning is energy-intensive. As the climate warms, increasing the use of air conditioning would further increase heat-trapping gases in the atmosphere. For this reason, cooling centers could be considered maladaptive: by treating the problem, they actually worsen it. Adaptations that reduce climate impacts without contributing to emissions should become a more central component of city-wide heat policy in the future. One example could be nature-based solutions—such as green roofs and tree cover— that help reduce local surface temperatures.

Furthermore, cities are currently grappling with cooling their populations during the COVID-19 pandemic. Cooling centers rely on congregating multiple people into enclosed spaces, which is risky in the pandemic. In response to the virus, heat adaptations have varied widely this summer: Los Angeles opened cooling centers with social distancing and mask mandates; New York planned to help residents pay their electricity bills; Phoenix booked hotel rooms to keep homeless people out of the heat. The pandemic has exposed a need to rethink our strategies for adapting to extreme heat.

Author: Katie Schneer

Katie interned at EESI in the summer of 2019. She joined the Environmental Defense Fund as a U.S. Climate Policy Fellow after graduating with a BA in Public and International Affairs from Princeton University in June 2020. This article is an adaptation of her undergraduate thesis.

Adapted from: Katie Schneer. (2020). Urban Adaptations to Extreme Heat. Princeton University senior thesis. http://arks.princeton.edu/ark:/88435/dsp014j03d261w