Abandoned land drives dangerous heat in Houston, researchers find

Gaby Clark
scientific editor

Robert Egan
associate editor

On a scorching Texas afternoon, some Houston neighborhoods heat up far faster than others. New research from Texas A&M University shows vacant and abandoned land is a big reason why.
A new study led by Dr. Dingding Ren, a lecturer in the Department of Landscape Architecture and Urban Planning, finds that vacant lots with vegetation can help cool surrounding areas. Abandoned buildings and paved lots do the opposite, raising land surface temperatures by as much as 20 degrees Fahrenheit.
Ren said many low-income residents run their air conditioning less to save money, leaving them even more exposed to the heat.
"Residents living in these vulnerable areas are more likely to suffer heat stroke and other heat-related illnesses," Ren said. "Because of more vacant land and abandoned structures, [these neighborhoods] retain more heat during the daytime and even experience higher overall temperatures at night, because the concrete absorbs heat and releases it slowly."
Drone data reveals hotspots
Houston ranks among the top 10 hottest cities in the U.S., and Ren set out to understand why.
Using more than 1,400 drone images and NASA satellite Landsat data, he mapped heat at a street-by-street level across seven sites, including residential neighborhoods, commercial strips and industrial zones. Each location had patterns of both above-average land surface temperatures and high social vulnerability, a measure for communities most at risk during disasters.
"The type of surface on vacant land matters significantly," Ren said. "Lots with bare soil or gravel tend to have higher land surface temperatures than those covered with vegetation, though lower than heavily built-up areas."
Houston alone contains roughly 45,000 acres of vacant land and 10,000 acres of abandoned buildings, according to the study.
Even a small cluster of abandoned structures in industrial areas can raise nearby land temperature dramatically.
Walking into danger
Higher surface temperatures can make public spaces, like sidewalks and bus stops, dangerously hot.
"Houston is famous as an unwalkable city," Ren said. "Low-income people are sometimes forced to walk or bike in this extreme heat with zero shading, and over time, being exposed like this every summer is not healthy."
Ren shared his own experience trying to navigate Houston. "Google Maps said it was a five-minute walk from my hotel to a pharmacy, but it took me 30 minutes with no shade, no red lights and no safe place to cross," Ren said. "That day, I even got heat stroke."
Ren said heat absorbed by concrete and rooftops lingers into the night, raising risks of heat-related illness while forcing households to spend more on cooling. The city's power grid feels the strain too, as residents rely heavily on air conditioning to stay safe.
Green space solutions
While the findings reveal serious public health risks, Ren said small-scale interventions could make a measurable difference for vulnerable residents.
"Low-income communities lack trees and green space," Ren said. "Green infrastructure would really help reduce their risk and also encourage healthier, more active living."
Vacant lots can also serve as a climate adaptation tool, making the outdoors safer. "If managed effectively, it can be redeveloped as green infrastructure gardens or shade areas to reduce the urban heat."
Ren plans to expand the research by combining his heat data with CDC health records. He is co-authoring the paper with Jiang Zheng, a doctoral student in urban and regional sciences, to study how heat exposure contributes to illness.
He hopes the findings will guide city leaders and planners in prioritizing cooling strategies for Houston's hottest, most vulnerable neighborhoods. Ren said its lessons may extend beyond Houston, too.
"If the problem presents even in one of the fastest-growing cities, then the situation could be worse in shrinking cities," where there may be even more vacant lots, Ren said.
Provided by Texas A&M University