New research from the University of California San Diego’s School of Global Policy and Strategy finds that low-income neighborhoods and communities with higher Black, Hispanic, and Asian populations experience significantly more urban heat than wealthier neighborhoods.
Researchers analyzed temperature data on 1,056 U.S. counties, which have 10 or more census districts. The authors were able to analyze surface temperature changes caused by urbanization on a neighborhood-by-neighborhood scale by using satellite data. Through leveraging a pixel-based image analysis to visualize and examine temperatures continuously over a large area, they were able to evaluate heating differences within cities. They compared these statistics to census district demographic information to quantify environmental inequities in urban climates. In 71 percent of the counties studied, land surface temperatures in communities with higher rates of poverty were up to 4 degrees Celsius, or 7 degrees Fahrenheit warmer, compared to the richest neighborhoods during the summer months.
“The physical features driving surface heat spikes in these urban environments are fairly consistent across the country, even for cities with very different geographies and histories,” said lead author Susanne Benz, who was a postdoctoral fellow at the University of California, San Diego while conducting the study. “Systematically, the disproportionate heat surface exposures faced by low-income communities with larger minority populations are due to more built-up neighborhoods, less vegetation, and – to a lesser extent – higher population density.”
“Particularly in summer, warming in cities due to alterations of the surface energy balance jeopardizes human health and productivity,” said Jennifer Burney, the Marshall Saunders Chancellor’s Endowed Chair in Global Climate Policy and Research at the School of Global Policy and Strategy and co-author of the study.
Extreme heat has been linked to a range of consequences for humans, from premature births, to lower test scores, decreases in productivity, and increased risk of heatstroke among children and the elderly.
The study, “Widespread Race and Class Disparities in Surface Urban Heat Extremes Across the United States,” was published in the journal Earth’s Future. It may be accessed here.