Heads above water

Using GIS methodology and 2006 census data, the document identifies that approximately 19 million people in the 23 coastal states of the conterminous U.S. live within 1 km of the shoreline, and 11.6 million live below a three-meter elevation. Florida, Louisiana, and New York have the highest absolute numbers of people living below 3 meters, while states like Rhode Island and Maine have high relative shares of their population within 1 km of the coast. These populations are identified as highly vulnerable to the combined effects of projected sea-level rise—estimated by the IPCC to be 18-59 cm by 2100—and increased cyclone activity.

• In the conterminous United States, approximately 19 million people (10.0% of the population of the 23 coastal states) live within 1 km of the shoreline, while 11.6 million people (6.1% of the coastal population) live below an elevation of three meters.
• Florida has the highest number of people living below 3 meters at 5.9 million (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, including Rhode Island, Maine, Florida, Delaware, and the District of Columbia, have over 20 percent of their population living within 1 km of the coast, making them particularly susceptible to sea-level rise and storm surges.
• Coastal communities face increased vulnerability due to the combination of enhanced cyclone activities and projected sea-level rise, with conservative 2007 IPCC estimates predicting 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} }