Scorched: Climate Change Turns Up the Heat on Austin

May 10, 2024
A worker struggles in the heat (Adobe Stock Image #637159967)

On one sweltering day in the summer of 2023, the thermometer in Austin hit a sizzling 110°F. Central Texans experienced the hottest summer since records began in 1897. The capital saw 80 days with 100-degree heat or over, and less than 1.5 inches of rain from June through August.  It was part of a brutal summer that strained the city's power grid and put many vulnerable residents at risk.

Indeed, at this point it’s probably a misnomer to call such stretches heat “waves.” They are now the new normal: the 10 hottest summers on record in Austin have all come since 1998. Scientists warn that such extreme heat events will only become more frequent and intense as global temperatures rise due to climate change.

"Heat is here, and it's going to get worse," said Marc Coudert, the climate resilience and adaptation manager in the City of Austin’s Office of Resilience. Speaking at this year’s Planet Texas 2050 Symposium at The University of Texas at Austin, Coudert stressed how the time had come to start talking about extreme heat as more than just a temporary shock. “Heat is a constant stressor impacting people's daily lives," he said.

The convergence of urbanization, poverty, aging infrastructure, and climate change creates a vicious feedback loop. This "urban heat island" effect caused by the replacement of shade- and oxygen-providing vegetation with heat-absorbing surfaces like concrete and asphalt leads to higher temperatures, driving up energy demands for air conditioning and, in turn, increasing greenhouse gas emissions. Every year, more people are being exposed to dangerous heat, with the elderly, outdoor workers, and low-income communities often facing the gravest risks.

Kenneth Thompson, an Austin native who has worked as a community organizer for decades, explained how heat can quickly spiral into crises for the most vulnerable. “When marginalized communities are impacted by an event such as the heat [wave] of 2023, there are cascading episodes that take place in these families,” Thompson said. “We see the homeless every day, and collectively as a community we respond and try to find places for them to be, and we do. But it's the ones we don't see that struggle most, that maybe end up homeless at some point because of cascading events [related to] heat.”

From left to right: Ashley Dawes, Kenneth Thompson, Dev Niyogi

From left to right: City of Austin's Ashley Hawes, community organizer Kenneth Thompson and UT's Dev Niyogi, at the 2024 Planet Texas 2050 Symposium. Photo credit: Johnny Holden

An Interdisciplinary Approach

To confront this escalating challenge, a diverse coalition of multidisciplinary teams at Planet Texas 2050 has launched several innovative projects. "There is no silver bullet," Coudert said. "There's no one thing we can do to mitigate heat in Austin. (The solution) has to cut across... different organizations and different community members."

One such effort, the UT Austin + City of Austin Climate Co-Lab, fosters collaboration between researchers and city officials. By combining academic expertise in climate science with real-world data and lived experience, the Co-Lab aims to develop practical tools, solutions, and policy recommendations for a hotter future.

Another key effort is called Thermalscape, which uses weather station data and thermal satellite imagery to create high-resolution maps of Austin's urban heat islands and model future scenarios. The maps reveal which neighborhoods experience the highest temperatures due to a lack of vegetation, abundance of heat-absorbing surfaces like roads and parking lots, and clustering of heat-generating commercial and industrial buildings.

"This kind of hyperlocal data is critical for targeting interventions and developing resilient strategies," said one of the project’s leaders, Dev Niyogi, a professor of earth and planetary sciences in the Jackson School of Geosciences and of civil, architectural and environmental engineering in the Cockrell School of Engineering. "We can't manage what we can't measure when it comes to extreme urban heat."

The maps have already influenced urban planning decisions in Austin by identifying heat-burdened communities that should be prioritized for new parks, trees, cooling centers and energy efficiency programs. They have also helped guide a pilot program known as the "cool pavement project," which is evaluating the potential efficacy of reflective surfaces that absorb less heat.

"There is no silver bullet. The solution has to cut across different organizations and different community members."

Marc Coudert, City of Austin

On the public health front, the Austin heat mapping data is being integrated into a new early warning system being developed by epidemiologist Ashley Hawes and her team at the City of Austin’s Department of Public Health. Official heat advisories are not issued until the temperature reaches a blazing 103°F, or 108°F heat index (which also incorporates humidity), even though most heat casualties occur at lower temperatures that strain vulnerable populations over longer durations. "Two-thirds of our heat deaths from 2019 to 2022 actually happened below the criteria for issuing an official alert," said Hawes. "Where's the gap and what are we missing? How can we do better?"

The new system will integrate real-time health data with forecasted temperatures and socioeconomic factors to automatically trigger protective actions and community outreach. "Public health is slow,” Hawes conceded, “but it's the right time to be talking about heat in a way that people get involved, and we work with our communities to serve them in the best way possible."

Digitizing Future Solutions

Looking ahead, the Planet Texas 2050 coalition is utilizing cutting-edge digital twin technology to simulate future climate risks. A digital twin is a virtual representation of a real-life object that visualizes large swathes of data about the physical space. The twins can serve as a shell for other researchers to apply data and give decision-makers new insights into the spaces they manage.

For example, Dev Niyogi's team has created "a new digital twin of the UT campus [that] gives the clearest picture yet of historical and current energy usage across the Forty Acres," according to Niyogi. This virtual UT model is a template for a broader digital twin for the Austin metro area, integrating energy use, vegetation, surfaces, population, emissions and more. "We deeply underestimate how much climate change will impact the city, as well as the opportunity available to alter the way we can evolve the city," Niyogi said. "With this tool, we hope to raise awareness of this opportunity so we can start asking questions about what our energy and future city might look like."

"We deeply underestimate how much climate change will impact the city, as well as the opportunity available to alter the way we can evolve the city."

 Dev Niyogi, UT Austin + City of Austin Climate Co-Lab

Unfortunately, scientific and technological solutions are not enough on their own. "The most dangerous and deadly jobs are those associated with building and maintaining our cities, and that threat is amplified by extreme heat," said Maggie Hansen, an assistant professor in the School of Architecture. "These are the physical spaces we need to fundamentally re-imagine and advocate for as designers."

The human cost of inaction is too high, and Austin's fight for adaptation is a microcosm of a global challenge. The lessons learned here will be crucial for cities around the world grappling with a hotter, more unforgiving climate. The scorching sun may be a symbol of Texas, but the future demands a new kind of resilience one built on collaboration, innovation and a commitment to protecting the most vulnerable. As Thompson said, "No one should lose their humanity due to a problem we are creating." 

Grand Challenge:
Planet Texas 2050