Cities are struggling with warmer, wetter weather. Better climate models could help.
Oct 3, 2023
This article originally appeared in Nexus Media News and is republished with permission.
Growing up in the marshy plains of the Texas Gulf Coast, Ellen Buchanan had seen her share of floods. But in 2017, when Hurricane Harvey dumped 40 inches of rain on her home in Silsbee, a suburb of Beaumont, even she was caught off guard.
“Harvey was a whole different thing,” Buchanan, 70, said. “It flooded places that had never flooded before. All the creeks and bayous that flow to the Neches River turned each community into its own little island.”
The Neches River, in turn, carried all of that water 15 miles south, to an already inundated Beaumont. There, it swamped the city’s main and secondary pump stations, cutting off water to 110,000 residents for more than a week. Without access to potable water, storm shelters full of shell-shocked evacuees were forced to seek safety elsewhere. Outside, they were greeted with the dank smell of sulfur dioxide, the result of hurricane damage to one of the region’s many petrochemical refineries.
In the aftermath, local officials, emergency responders, and residents like Buchanan wondered how they would prepare for the next storm. Could street-level structures like bioretention ponds and stormwater tunnels soak up the rain next time? Or did they need more significant interventions: levees, flood gates or even relocation assistance? Data-driven answers were hard to come by.
While meteorologists have gotten quite adept at predicting the path of massive storm systems like hurricanes, anticipating the associated impacts of rain, flooding and storm surges at the street level is often more complicated. That’s because existing computer-generated models don’t account for the block-by-block, neighborhood-by-neighborhood factors that impact a city’s microclimates.
“Most models have pretty coarse resolution of about 25 to 50 kilometers,” said Gary Geernaert, director of the climate and environmental sciences division at the Department of Energy (DOE). When researchers run model simulations to learn how even stronger storms might affect southeast Texas, towns like Silsbee and Beaumont — and all the creeks, parks, parking lots, and neighborhoods that form their microclimates — are obscured. “The model treats them kind of like a black box,” Geernaert said.
Without a clear picture of what’s to come, Buchanan has watched with concern as neighbors in her corner of the metro, a community with large Black and Hispanic populations, resumed buying the cheap houses that continue to be built in the flood plains.
But better models — and community-informed solutions — may only be a few years away.
In 2022, the DOE launched a $100 million program to create more granular urban climate models. Over the next five years, Baltimore; Chicago; the urban corridor of Phoenix, Flagstaff, and Tucson, Arizona; and southeast Texas will all get Urban Integrated Field Laboratories (Urban IFLs). In each region, teams will set up monitoring equipment to study these areas’ many microclimates.
“These are spectacular instruments, and we already have some beautiful data coming out,” said Paola Passalacqua, a professor of engineering at the University of Texas at Austin and the principal investigator of the southeast Texas project.
“[Beaumont] is a community that gets acute shocks — floods — on top of long-term stressors like pollution,” Passalacqua explained. “During flooding events, there can be major chemical releases into the air and the soil. But for both flooding and air pollution, we lack information on what is going to happen under future climate scenarios and how to prepare for that.”
The field laboratories are not the first attempt to build localized climate models. Insurers, real estate investors, and even nonprofits have been assessing risk at the hyperlocal level for years. But this is the first time such efforts have the heft of the federal government behind them, and the first time the modeling is used to develop hyperlocal solutions.
“We start with the communities. We ask, ‘What is of interest to you?’” Passalacqua said. “This helps us decide which models to run based on the preferred mitigation strategies of the community.” The Urban IFLs rely heavily on local expertise, bringing in neighborhood associations, first responders, and community advocates.
Geernaert, of the DOE, said that community buy-in is central to the process of building these models and drafting resiliency plans. “It works better if the community is part of the process,” he said. “So it’s not us saying, ‘We’re going to give this to you’ — it’s ‘You made this, too.’”
The Urban IFL program is part of the Biden administration’s Justice 40 initiative, a broader effort to prioritize investments in “diverse and underrepresented communities affected by a changing climate.”
“A bottom-up approach ensures the community gets tailored solutions,” said Ashish Sharma, an atmospheric scientist and modeling lead for the Chicago lab. There, researchers are focusing their efforts on the historically disenfranchised South Side, which is more prone to flooding than wealthier, whiter neighborhoods. There are a host of factors that may contribute to the South Side’s flooding problems: a lack of stormwater infrastructure, an excess of asphalt and other impervious surfaces, and a lack of trees and other rain-absorbing surfaces.
Many cities have invested in planting trees to absorb runoff, provide shade, and store carbon, but trees aren’t a one-size-fits-all answer and lots of questions about their efficacy remain. To figure out if a leafy canopy is the best option in Chicago neighborhoods, Sharma said, “We’re developing new models for trees, so we can really understand at the meter-scale how they interact with the surroundings.”
According to Passalacqua, each field laboratory’s findings will be published in accessible “plain-language summaries,” that local leaders can understand and act on — and share with other cities looking to adopt best practices.
Buchanan, who is a member of the Southeast Texas Urban IFL, is eager for the answers she hopes the project will provide. “Can you stop the water? No. Then what can we do? How can we make a safer place for people to live, so they can still go to the schools and churches that they always have?”
Buchanan said that her first UIFL meeting was a bit overwhelming, with lots of stakeholders speaking passionately about lots of different interests. “I just hope it will bring the community together,” she said.
Passalacqua anticipates it will take time for the group to gel. “This is a truly multidisciplinary project, and the groups that are collaborating — whether they’re community members, modeling experts, climate experts — typically speak different languages. Now we’re making a new language.”
This story was originally published by Grist with the headline Cities are struggling with warmer, wetter weather. Better climate models could help. on Oct 3, 2023.