Breaking down climate change, a neighborhood at a time

The world is full of “huge, gnarly problems,” as Oak Ridge National Laboratory research scientist and musician Melissa Allen-Dumas puts it — no matter what line of work you’re in.

That was certainly the case when she would wrestle with a tough piece of music.

“There are passages in music that are much harder than other passages, and that require much more practice,” said Allen-Dumas, who performed and taught the violin and viola professionally for much of her life. “It’s important to take those and break them down into easier bites for yourself, and to solve smaller problems.”

Chopping big problems into manageable pieces, as it turns out, is also the crux of her work now as a computational scientist in ORNL’s Computational Sciences and Engineering Division. There, she tackles global climate change by developing methodologies that scale that big, gnarly problem down to the level of cities — even specific neighborhoods. Pulling together different kinds of data — on weather, building size and shape, migration patterns and demographics, for example — she sheds light on the effects of climate change at the local scale, and on how communities can best prepare for them.

In a 2020 study using data on ORNL’s campus and a Chicago neighborhood, for example, Allen-Dumas and her co-authors used computer simulations to project how different proposed developments would affect the building site’s microclimate. They learned that, depending on variables such as building design, land use and population density, some scenarios would lead to notably warmer microclimates. What’s more, those effects extended beyond the development’s boundaries and into the surrounding area.

Buildings consume three-quarters of the electricity used in the United States, so being able to assess the effect of their shapes and sizes could help cities better mitigate climate change. Allen-Dumas hopes her methodologies can be developed into tools that officials addressing climate change can use at the local level.

“Looking at this from a climate lens,” she said, “I am fascinated with the idea that a few people can make a huge difference, and I would love to see that in action.”

From music to science

As a child, Allen-Dumas knew science had the power to make a difference. Her father, Dan McGuire, was a nuclear physicist — a career that eventually landed him at ORNL. Although she didn’t understand his work in detail, she grew up with an appreciation of science and the scientific method, a theme that has continued through her life.

It was music, however, that first captured her imagination. Growing up in Northern Colorado, she absorbed the string music playing both on the home stereo and from the hands of musicians who came by for bow and instrument repairs, her father's side gig. She started violin lessons at age nine, and eventually earned a bachelor’s degree in music education at the University of Northern Colorado. In the years that followed, she performed and taught music and choir.

But science reemerged as a theme in her life when, at age 30, she married ORNL computational scientist John Allen. After relocating to East Tennessee, Allen-Dumas dove deeper into science when she took up her new husband’s passion, flying single-engine airplanes. Working toward her own pilot’s license, she learned about wind, temperature and humidity, and how to apply that knowledge in a hands-on way.

“That really got me interested in the atmosphere and in weather,” Allen-Dumas said.

After her husband’s death in 2007, however, that interest grew into a mission as Allen-Dumas began seeing her life through a new lens. With science, she thought, she could make a bigger difference.

“I realized I was at a transition in my life in a lot of ways,” Allen-Dumas said. “So, if I was going to jump from music to science, that was the moment at which to do it.”

Allen-Dumas enrolled at the University of Tennessee, where she earned a master’s degree in environmental engineering. Then, through the ORNL-affiliated Bredesen Center for Interdisciplinary Research and Graduate Education, she earned a doctorate in energy science and engineering. She has been connected to ORNL ever since, landing an internship and then a postdoctoral fellowship before signing on as a research scientist in 2017.

Allen-Dumas did not find her groove immediately at ORNL’s sprawling campus. Early on, as an atmospheric scientist working in the former Geographic Information Science and Technology group, she felt like a violinist in the percussion section. But she grew to appreciate the novel ideas that can arise when collaborating with specialists from other fields. By integrating her climate and weather data with her colleagues’ high-resolution population data — they could break down U.S. populations to the size of a New York City block — the collaborators could, Allen-Dumas realized, see and predict climate change effects at much smaller, actionable scales.

“If you understand where the population is, and you understand the weather and the climate that's coming through a certain space, then there's a lot that you can understand about the interactions,” Allen-Dumas said. “There's a huge opportunity for the integration of these things.”

Growing into her science

Allen-Dumas has built a career on that opportunity. Much of her research examines climate impacts on critical infrastructure and the unique challenges facing the southeastern U.S., which produces more carbon dioxide and has a faster-growing population than other regions of the country.

In one study examining data from Knoxville and Atlanta, Allen-Dumas and her co-authors demonstrated a methodology for planning for future land, water and energy needs in the face of climate change. The study presented numerous scenarios for those cities in detail, highlighting the advantages and trade-offs of each. Atlanta could reduce its carbon footprint by heavily investing in solar power, for example, but that path would require significant land resources. The findings could help urban planners make better decisions as they project long-term investments in infrastructure.

Allen-Dumas’s other work includes development of a method to pinpoint which electrical service areas in the southern U.S. will be most vulnerable as populations grow and temperatures rise, and an analysis of post-Katrina climate migration revealing where the quarter of New Orleans residents who left the city for good ended up.

In her research, Allen-Dumas also finds evidence of how disadvantaged communities suffer disproportionately from climate change, an issue the federal government has been seeking to address. In an upcoming study examining the city of Las Vegas, for example, she and her colleagues found that more vulnerable populations tend to live in older buildings located in the hottest part of the city. Currently, Allen-Dumas is working on models that predict what the cities of the future will look like, and how to factor these new urban morphologies into simulations on climate change.

ORNL’s world-leading supercomputers and massive data sets have been critical to her work, Allen-Dumas said. But more important, she said, is the ability to collaborate with lab colleagues who are recognized authorities in diverse areas of expertise. Her music career prepared her well for science teamwork.

“There are times when you need to lead — you need to play that first violin part really well — you need to be the soaring melody in projects,” said Allen-Dumas, who keeps up with her music as a member of two local quartets. “And there are other times when you have to play a supporting part — the harmony, so to speak — just as well.”

Increasingly, Allen-Dumas is interested in supporting not just her fellow scientists, but the government and industry officials on the ground making decisions on their communities’ futures. Inviting these stakeholders to add their voices to her work, she said, could help her build them better tools for weighing their options.

“I think those of us who are doing the science, when we see the results, think, ‘Oh, those speak for themselves,’” she said. “But I'm not sure that that those things actually do speak for themselves when policymakers are having to make a decision for tomorrow and next year and decades and in the future. I think we're at a point now where we want to maybe start involving the stakeholders in helping to design the science.”

After all, when it comes to the huge, gnarly problem of climate change, we all have a part to play.

This article originally appeared on Oakridger: Breaking down climate change, a neighborhood at a time