Coastal flooding will threaten homes of 2.5 million Americans by 2050: Analysis

Climate Central's Coastal Risk Finder projects 100-year coastal flood zones to expand as rising seas amplify risks, especially in the Northeast and Florida

PRINCETON, N.J., April 2, 2025 /PRNewswire/ -- Within 25 years, rising seas will extend the potential reach of a severe coastal flood over areas where more than 2.5 million Americans live today, according to a new Climate Central analysis. That includes the homes of more than 270,000 New York City residents, as well as large numbers of people in Boston, New York's Long Island, and coastal New Jersey. By state, Florida faces the greatest threat, with more than 500,000 residents living within the projected risk zone of a 100-year flood by mid-century.

Florida homes represent roughly one-quarter of the 1.4 million homes within reach of a severe coastal flood by 2050. Those sites are mapped by Coastal Risk Finder, a publicly available online screening-level tool that combines elevation data and the latest scientific modeling of local sea level rise and coastal flood projections to identify at-risk communities and support research into solutions. The affected areas could be impacted by floodwaters during an event with a 1% annual likelihood of occurring, or a so-called 100-year flood.

"As sea level rise accelerates in response to climate change, flooding during coastal storms will threaten more homes in the U.S. every year," Kristina Dahl, vice president for science at Climate Central, said. "By pinpointing local risks, science and technology can lead the way toward solutions that protect coastal residents in an increasingly hazardous future."

Climate Central's analysis is based on the most recently available data from the U.S. Census and sea level rise projections from the United Nations' Intergovernmental Panel on Climate Change (IPCC). Findings are based on the SSP2-4.5 pollution pathway, in which pledged commitments to reduce carbon pollution are met.

By visualizing the findings in interactive maps, Coastal Risk Finder can flexibly support coastal resilience initiatives and awareness efforts.

"The Gullah/Geechee Nation has consistently used Risk Finder due to the fact that it is user friendly and helps us to help policymakers see data in a concise manner so that they can make the best decisions to sustain our coast," Queen Quet, chieftess of the Gullah/Geechee Nation, said. "Sustaining our coast sustains our culture."

The full report is available at www.climatecentral.org/report/coastal-flood-risk-across-US, and Coastal Risk Finder is available at app.climatecentral.org/coastal-risk-finder.

About Climate Central
Climate Central is a non-advocacy, non-profit science and news organization providing authoritative information to help the public and policymakers make sound decisions about climate and energy.

SOURCE Climate Central