Heads above water

This fact sheet presents GIS-based estimates of populations in the conterminous United States living in coastal areas vulnerable to sea-level rise and storm surges, specifically those residing within 1 km of the coast or below 3 meters in elevation.

• In the conterminous United States, approximately 19 million people live within 1 km of the shoreline, representing 10.0% of the population across 23 coastal states and 6.4% of the total U.S. population.
• About 11.6 million people in the conterminous U.S. live in areas below 3 meters elevation, which is 6.1% of the coastal population. Roughly 6.3 million people meet both criteria of living below 3 meters and within 1 km of the coast, accounting for 3.3% of the coastal population.
• Florida has the highest number of people living in areas below 3 meters, with 5.9 million people (32.5% of its population), followed by Louisiana with 1.2 million (27.6%) and New York with 1.0 million (5.4%).
• Certain states and the District of Columbia have over 20% of their population living within 1 km of the coast, including Rhode Island, Maine, Florida, Delaware, and the District of Columbia, making them potentially most affected by sea-level rise or storm surges.
• The vulnerability of coastal communities is driven by the combination of enhanced cyclone activities and projected sea-level rise; 2007 IPCC estimates predict a rise of 18-59 cm by the year 2100.

APA

Inter-American Institute for Global Change Research (2010). Heads above water. https://iai.int/admin/site/sites/default/files/uploads/2014/06/Snapshot3_heads_above_water.pdf

Chicago

Inter-American Institute for Global Change Research. Heads above water. 2010. https://iai.int/admin/site/sites/default/files/uploads/2014/06/Snapshot3_heads_above_water.pdf.

Wikipedia

{{cite report |author=Inter-American Institute for Global Change Research |title=Heads above water |date=2010 |url=https://iai.int/admin/site/sites/default/files/uploads/2014/06/Snapshot3_heads_above_water.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{interamericaninstituteforglobalchangeresearch2010heads, author = {{Inter-American Institute for Global Change Research}}, title = {{Heads above water}}, institution = {Inter-American Institute for Global Change Research}, year = {2010}, url = {https://iai.int/admin/site/sites/default/files/uploads/2014/06/Snapshot3_heads_above_water.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }