Environment/Climate Change
Identifying Climate Vulnerability Profiles of U.S. Cities through Cluster Analysis Andrea Titus and Lorna Thorpe* Hanxue Wei Ben R Spoer Andrea Titus Alex Azan Anna Bershteyn Lorna E Thorpe
Background and Objectives: Understanding patterns of vulnerabilities to climate risk is critical for targeted climate adaptation and public health interventions. However, city-level clustering analyses for climate vulnerability in the U.S. are limited. This study employs data-driven methods to group U.S. cities into distinct climate vulnerability profiles, facilitating the identification of shared challenges and collaborative solutions.
Methods: We analyzed annual city-level data from 1,103 U.S. cities from 2015 to 2021 obtained from the City Health Dashboard and other public sources, focusing on baseline weather variables (e.g., temperature, humidity, precipitation, and air pollution) and climate-driven extreme weather events (e.g., extreme heat days, drought frequency, tornado events, and coastal or riverine flood hazards). We employed K-means clustering and latent trajectory modeling to identify city typologies, with sensitivity analyses using hierarchical clustering and longitudinal trend analysis.
Results: Analyses using K-means clustering based on multi-year mean values suggest 3 main climate risk typologies of U.S. cities, with clear regional differentiation. The first cluster, located predominantly in the Southeast region, faced significant tornado and flood risk, higher precipitation, higher humidity, and elevated maximum temperatures. The second, predominantly in the Northeast and Midwest, had lower flood risk, lower maximum and minimum temperatures, and lower humidity. The third, predominantly in the Southwest and West, faced higher drought frequency, more extreme heat days, higher PM2.5 concentrations, and lower precipitation.
Conclusion: The current analyses show that US cities have three distinct climate risk profiles that correspond well to geographic regions. Identified city profiles can guide tailored adaptation strategies, enabling cities with similar challenges to collaborate on effective solutions.