Map Shows US States Warned of Sea Level Rise in 2050, 2100

By Hollie Silverman

Deputy Weekend Editor

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More than 5,500 toxic and hazardous sites across the United States are projected to be at risk of coastal flooding as a result of rising sea levels by 2100, with nearly 3,800 facing similar danger as soon as 2050 under high-emissions scenarios.

A new peer-reviewed study led by University of California scientists has highlighted these risks in a series of detailed maps and state-by-state analyses, revealing the scope of the threat to public health and American communities.

According to the data, Louisiana has the most hazardous sites at risk, with more than 1,000 identified locations at risk, while other southern, East Coast and West Coast states have fewer than 1,000 per state.

With projections suggesting much of the risk is already locked in because of past emissions, comprehensive adaptation and mitigation strategies are required to protect millions of Americans from exposure to toxic floodwaters.

Why It Matters

The findings carry major implications for public safety, environmental health and resilience planning along U.S. coastlines.

The research underscores that hazardous sites—ranging from sewage and toxic waste facilities to oil and gas operations—are increasingly vulnerable to coastal flooding as sea levels rise.

The study also reveals that the dangers fall disproportionately on marginalized and lower-income communities, raising urgent questions about environmental justice and disaster preparedness.

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What To Know

The study, published in Nature Communications, identified more than 5,500 hazardous sites nationwide at risk of flooding from sea level rise by 2100 if emissions continue unchecked, with roughly 3,800 sites threatened as early as 2050. They include facilities handling toxic waste, sewage and a variety of industrial pollutants.

The risk is not uniformly distributed. Seven states—Florida, New Jersey, California, Louisiana, New York, Massachusetts and Texas—account for nearly 80 percent of the hazardous sites at risk by 2100.

Neighborhoods near at-risk toxic sites often have higher proportions of renters, low-income residents, seniors, linguistically isolated households and people of color. Researchers found that these communities are less likely to have resources to prepare for or recover from toxic floods, highlighting environmental inequity.

In 2024, the National Oceanic and Atmospheric Administration (NOAA) projected sea levels to rise by about 10-12 inches by 2050, exposing coastal areas to more regular flooding, especially during high tides and storms.

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By 2100, estimates by the Intergovernmental Panel on Climate Change (IPCC) suggest sea levels could rise by up to 6.6 feet under worst-case scenarios.

Cities and regions highlighted as vulnerable include Miami and the Florida Keys, New Orleans, Galveston, Charleston and Boston, among others.

Large portions of the Gulf and Atlantic coasts are expected to be particularly hard-hit, with severe consequences for local economies and infrastructure.

The peer-reviewed study used high-resolution maps, facility data and demographic indicators to assess flood risk and social vulnerability.

Flood projections were based on a 1 percent annual probability event—a so-called 100-year flood—and considered high- and lower-emissions scenarios. The research was funded in part by the U.S. Environmental Protection Agency.

What People Are Saying

Dr. Lara Cushing, UCLA Fielding School of Public Health, study co-author: “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. This analysis makes it clear that these projected dangers are falling disproportionately on poorer communities and communities that have faced discrimination and therefore often lack the resources to prepare for, retreat, or recover from exposure to toxic floodwaters.”

Dr. Rachel Morello-Frosch, UC Berkeley’s School of Public Health: “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."

What Happens Next

Researchers emphasized that moderate emissions reductions could prevent more than 300 hazardous sites from facing increased flood risk by 2100.

Policy actions at the local, state, and federal levels—such as better land-use planning, disaster preparedness and targeted adaptation resources for vulnerable communities—will shape the extent of damage and exposure in coming decades.

Further updates on regulatory and climate initiatives are expected as the risks documented in the study gain national attention from policymakers, advocacy groups and local governments.

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