Images of catastrophic flooding filled social media in October as the remnants of Tropical Storm Ophelia dropped more than 6 inches of rain on New York City in less than 24 hours, inundating streets, subway tunnels and basement apartments across the city.

Across the river in Hoboken, however, the effects of the storm were relatively mild. Schools let out on time, and an arts festival went on as scheduled.

The difference?

In a word: preparation.

In the wake of Hurricane Sandy, Hoboken poured millions of dollars into its waterfront, constructing new parks and cisterns to effectively absorb stormwater in the event of heavy rain. It also redesigned its streets to include more gardens and porous surfaces and reduce runoff.

It’s an example of the kinds of adaptive measures that cities will need to take if they hope to mitigate the worst effects of climate change moving forward — from flooding, extreme heat and rain to diminishing air quality.

Building on its pioneering Country Index, which ranks climate vulnerability and readiness across more than 180 countries, the University of Notre Dame’s Global Adaptation Initiative (ND-GAIN) will soon begin tracking the progress of such efforts in cities around the world. Based on evolving climate vulnerability and adaptation research, the Global Urban Climate Assessment (GUCA) aims to develop a pilot decision-support tool to inform actions and investments in urban areas.

“As society moves into an increasingly urban future, comparable city-level information is critical to better understand the complex challenges global cities are facing,” said Danielle Wood, project director at ND-GAIN and professor of the practice in the College of Engineering. “While national-level data, like that provided in ND-GAIN’s Country Index, offers an overview of climate risk, GUCA can facilitate resilience assessments and interventions across and within cities, where impacts are most felt.”

Using both remote sensing and secondary data, GUCA will provide the first assessment tool across multiple global cities on consistent resilience measures. The pilot begins with 10 densely populated cities: Amman, Jordan; Beijing, China; Berlin, Germany; Bogotá, Colombia; Jakarta, Indonesia; Kinshasa, Democratic Republic of the Congo; Mogadishu, Somalia; Mumbai, India; Rio de Janeiro, Brazil; and Shenzhen, China — with Abuja, Nigeria, and Panama City, Panama, as potential alternates.

Based on the pilot’s findings, ND-GAIN may expand the assessment globally to include all cities with populations higher than 1 million. GUCA is scheduled to be complete in fall 2024.

Wood is serving as principal investigator on the pilot project. Additional faculty researchers on the team include:

• Diogo Bolster, associate director of the Notre Dame Environmental Change Initiative (ND-ECI) and the Frank M. Freimann Professor of Hydrology and Henry Massman Department Chair in the Department of Civil and Environmental Engineering and Earth Sciences.
• Paola Crippa, assistant professor in the Department of Civil and Environmental Engineering and Earth Sciences.
• Alan Hamlet, associate professor in the Department of Civil and Environmental Engineering and Earth Sciences.
• Matthew Sisk, associate professor of the practice at Notre Dame’s Lucy Family Institute for Data and Society.
• Alexandros Taflanidis, professor in the Department of Civil and Environmental Engineering and Earth Sciences.
• Jennifer Tank, director of ND-ECI and the Ludmilla F., Stephen J. and Robert T. Galla Professor of Biological Sciences.
• Kevin Walsh, associate teaching professor in the Department of Civil and Environmental Engineering and Earth Sciences and director of the Master of Engineering program.

The team, which also includes early career researchers, postdoctoral scholars, doctoral students, Master of Global Affairs students and undergraduates, will identify a suite of environmental, economic and social indicators to be delivered through an interactive geographical information system platform for a visual, comparable view of urban climate resilience.

Like its parent index, GUCA will be a free and open-source tool designed to help governments, nongovernmental organizations and investors direct funding where it’s most needed, identify opportunities for adaptation and determine where cities are most vulnerable.

“Adaptation is critical for building resilience, reducing vulnerabilities and ensuring livelihoods in the face of climate change, but success will require a combination of strategies implemented at local, national and global levels to address the multifaceted challenges posed by a changing climate,” Tank said.

Globally, cities produce more than 70 percent of greenhouse gas emissions. Industrialization, transportation and reliance on fossil fuels and human activity are driving an increase in the planet’s core temperature. Though world leaders pledged to limit emissions and prevent global temperatures from exceeding 1.5 degrees Celsius as part of the Paris Agreement, climate experts have repeatedly warned that progress is not happening fast enough.

As extreme climate events grow in intensity and frequency, so does the need and the urgency for scalable adaptation measures addressing vulnerabilities of the world’s cities.

Along Mexico’s west coast, residents are still recovering from Hurricane Otis, which made landfall in October and rapidly intensified from a tropical storm to a Category 5 hurricane in less than 24 hours. Otis devastated the region, claiming dozens of lives and leaving dozens more missing.

The National Oceanic and Atmospheric Administration has called Otis “the strongest hurricane in the Eastern Pacific to make landfall in the satellite era.”

Tracy Kijewski-Correa, the William J. Pulte Director of the Pulte Institute for Global Development and professor of engineering and global affairs, is an expert in disaster risk reduction and the director of the NSF-funded Structural Extreme Events Reconnaissance (StEER) Network. StEER’s ongoing data collection confirms that Otis was an unprecedented storm that tested the limits of coastal communities.

“We’re seeing some of the most extensive cladding failures we’ve ever observed in high-rise buildings,” Kijewski-Correa said. “We’re also looking closely at the building code by which these buildings were designed. Based on the evidence we have so far, from a wind speed perspective, Otis may have been one of the strongest hurricanes of all time, which would certainly outstrip local codes that had not anticipated a storm of this intensity.”

While coastal cities bear the brunt of increasingly dangerous hurricanes, elsewhere, record-breaking heatwaves are straining electrical grids and threatening human life in vulnerable populations. Power generation, transportation and wildfires pose a continued threat to air quality. Drought and flooding impact crop yields. And saltwater intrusion in coastal areas has led to contaminated ground and freshwater systems.

“With mounting challenges and finite resources, decision-support tools serve as an important resource for prioritizing adaptation to the changing climate,” Wood said. “Translating research into open-source tools demonstrates how research can be of service to the common good, providing knowledge to assess needs and opportunities for adaptation planning and improved resilience.”

ND-GAIN is a program within Notre Dame’s Environmental Change Initiative, with more than 60 faculty across several disciplines pursuing research solutions for some of the key environmental challenges of our time.

For more on ND-GAIN and to see the latest rankings, visit gain.nd.edu.

For more on ND-ECI, visit environmentalchange.nd.edu.

Contact: Jessica Sieff, associate director, media relations, 574-631-3933, jsieff@nd.edu

Originally published by Erin Blasko and Jessica Sieff at news.nd.edu on November 30, 2023.