Approximately 5,500 hazardous sites in the United States could face coastal flooding by 2100 if greenhouse gas emissions continue to rise, according to a new study published in Nature Communications. The research was led by teams from UC Berkeley, UCLA, and Climate Central.
The study assessed more than 47,600 coastal facilities—including power plants, sewage treatment centers, fossil fuel infrastructure, industrial sites, and former defense locations—across all U.S. coastal states and Puerto Rico. Sites were considered at risk if they could be affected by a flood event with a 1% annual chance of occurring (a so-called 1-in-100-year flood), under scenarios where emissions either increase through the century or stabilize after 2100.
“Flooding from sea level rise is dangerous on its own—but when facilities with hazardous materials are in the path of those floodwaters, the danger multiplies,” said Lara Cushing, professor at UCLA Public Health and co-leader of the study alongside Rachel Morello-Frosch of UC Berkeley’s Department of Environmental Science, Policy, and Management and School of Public Health.
Researchers found that under a high-emissions scenario, about 11 percent of these coastal sites may be at risk from sea level rise-related flooding by 2100. Nearly 3,800 facilities could be threatened as early as 2050. Seven states—Louisiana, Florida, New Jersey, Texas, California, New York, and Massachusetts—contain nearly four-fifths of the identified at-risk sites.
The analysis also highlighted disparities among populations living near these hazardous sites. Neighborhoods with one or more facilities vulnerable to flooding have higher proportions of renters; households living in poverty; Hispanic residents; linguistically isolated households; households without vehicles; seniors; and non-voters compared to neighborhoods without such risks.
“Coastal communities, including underserved groups that are working to fortify their resilience to climate change need access to critical data and resources to plan for the future,” said Morello-Frosch. She added that recent difficulties accessing information from FEMA and NOAA have made it harder for communities to adapt.
Additional UC Berkeley contributors included Energy and Resources Group alumni Nicholas Depsky (PhD ’23) and Seigi Karasaki (PhD ’24).
Related coverage can be found in Inside Climate News (“As Seas Rise, So Do the Risks From Toxic Sites”), KQED (“Hundreds of California and Bay Area Hazardous Sites Could Face Future Flooding”), and Associated Press (“Thousands of US hazardous sites are at risk of flooding because of sea level rise”).
