Global Heating Will Hit Socially Vulnerable U.S. Communities First and Hardest

As temperatures increasingly exceed the ability of electric fans to cool homes affordably, a new study highlights the extent to which extreme heat is already making socially vulnerable communities increasingly unlivable across the contiguous United States—and how this trend will continue as the planet warms.

Published today in the AGU open-access journal Earth’s Future, the paper finds that, from 1951-2023, people in high-vulnerability areas (as defined by the Social Vulnerability Index) experienced temperatures on average around 1.6°C (~3°F) hotter than those in low-vulnerability areas—a gap that has grown in recent years and is likely to persist under future global warming scenarios.

So too, these high-vulnerability communities are found to experience more days per year where air temperatures exceed the thresholds where electric fans can provide effective cooling—another disparity expected to grow under future climate change as residents seek affordable ways to address increasingly intolerable heat in their homes.

Commenting on these findings, lead author Luke Parsons—a climate scientist at The Nature Conservancy—explains: “We know that socially vulnerable communities are on the frontlines in a rapidly warming world, but our findings illustrate the harsh reality of how heat inequity will grow in the United States as we continue to warm the planet.”

“Although that 1.6°C (~3°F) disparity may not sound dramatic in isolation, for some communities it represents the difference between hard-working families thriving or barely surviving without air-conditioning and between the low-income elderly being able to cool themselves safely using cheap electric fans or having to consider higher-cost options that can be economically unsustainable,” he adds.

Led by scientists from The Nature Conservancy (TNC) alongside researchers from University of Utah, Dartmouth College, Environmental Defense Fund, NSF National Center for Atmospheric Research and Duke University, the paper combines gridded climate observations with high-resolution projections to highlight how disparities in the heat experienced by these communities have grown since the 1950s and will continue to grow as this century progresses.

Adding further context, senior co-author Fiona Lo—a climate scientist with Environmental Defense Fund—said: “Climate change is already here—it's just not evenly distributed. There are neighborhoods that lack such luxuries as air-conditioning, tree cover and swimming pools that help reduce heat exposure. As climate instability leads to greater incidence of extreme heat, we hope this study acts as a call-to-action—ensuring any climate adaptation funding that does exist is directed towards these most socially-vulnerable communities as a priority.”

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Parsons L.A., Erbaugh J.T., Lo F., McCrary R., Raman S.R., Shindell D., Ward A., Wolff N.H. Climate Change and Disparities in Extreme Heat Exposure for Socially Vulnerable Areas in the Contiguous United States. Earth’s Future.