30 U.S. Cities Most Vulnerable to Extreme Heat

Recall for a moment the most oppressively sweltering summer days you’ve ever felt. If you were in a city, you remember the stifling heat radiating off the pavement, the thick air that was hard to breathe, and then the TV reports of seniors without air conditioning succumbing to the triple digits. Think Chicago in July 1995 (when temps peaked at 106 F), or the European heat wave of 2003 that killed 30,000 people.

That level of heat is about to become dangerously common, with potentially disastrous effects in cities across the United States. As global warming kicks up the thermostat over the next century, urbanites – particularly the poor and elderly – will be the most vulnerable to its effects, primarily because of the urban heat island effect, according to a report released last week by the National Wildlife Federation and Physicians for Social Responsibility.

“More Extreme Heat Waves: Global Warming’s Wake Up Call” ranks 30 large U.S. cities according to their extreme heat risk factors (see below), and describes the ill effects of regular heat waves, including exacerbated air pollution due to increased smog-forming ozone; increased incidence of illnesses like asthma, especially among the poor and people of color; and more heat-related deaths among the elderly who can’t afford air conditioning.

The Extreme Heat" report joins what you could call a hot list of similar findings over the past two weeks: that muggy days are becoming more common in California, and that the number of August days above 95 F will soar across U.S. cities, and that the Midwest will see a large temperature increase by the end of the century.

Source: More Extreme Heat Waves: Global Warming’s Wake Up Call Report

The two obvious takeaways for all local governments – not just these cities – are the need for continued mitigation efforts to slow the overall warming trend, and the need for adaptation planning now to deal with extreme heat and other impending impacts. NWF’s report adds a bit of good news, that cities can cool their neighborhoods by creating more green spaces (parks, green roofs) and putting in place public health measures to cope with extreme heat events.

I spoke with Rebecca Carter, ICLEI’s Adaptation Manager, who added this about the need for local government action:

There’s no doubt that this report contains scary information. Extreme heat is one of the impacts that we can predict with greater certainty -- and it will lead to more deaths and illness. But this is also an impact with effective solutions that are not always expensive to implement. Take, for example, City of Chicago’s program in which neighbors check on their elderly neighbors during heat waves, or its cooling centers where people without air conditioning can find relief.

Chicago is a great role model for other local governments to follow, since its planners have conducted an extensive risk assessment and implemented a range of adaptation tactics to prepare for extreme heat events and manage the heat island effect.

• To learn more about Chicago’s efforts, local government planners can view the free Chicago Area Climate Change Quick Guide: Adapting to the Physical Impacts of Climate Change.
• For a more detailed look at how climate change will disproportionately affect the poor and people of color, view The Climate Gap report written by USC researchers.