By 2050, global sea levels could increase by 1 foot from where they were at the start of the millennium. Iconic beaches, large city centers, and quaint coastal towns will all have to be adapted for higher water levels.
Sea level rise means more than just coastal land eaten up by the ocean. It will cause more inland neighborhoods to be at risk of storm surges during hurricanes and high tides, more regular flooding, and saltwater intrusion into freshwater resources.
For communities facing the brunt of shifting waters, planning for resilience has become paramount. At Florida International University in Miami, where sea levels are expected to rise by 10 to 17 inches between 2000 and 2040, researchers utilize wind and water machines to simulate hurricane conditions. That way, experts can design buildings strong enough to withstand higher ocean levels and future extreme weather events.
Yet in many places across the U.S., these plans aren't implemented fast enough. In 2023, residents of Louisiana's Isle de Jean Charles were forced to relocate further into the state due to rising waters, which had swallowed up 98% of the island's turf. And in July 2024, the Key Largo tree cactus in Florida was declared extinct after rising sea levels swamped its soil—the first sea level rise-related extinction recorded in the U.S.
Continued flooding and extreme weather events highlight the urgency of infrastructure fixes to mitigate sea level rise, but such plans are often expensive. An April 2024 study from the Center for Climate Integrity estimated that Los Angeles County must spend $12.5 billion over the next 15 years to alleviate the effects of climate change, including rising sea levels. Across the country, the federal government awarded Maine a $69 million grant in July 2024 to improve the state's "climate resilience" in the face of higher waters.
Planning for the future is also challenging for smaller communities. Solutions like paying to move and demolish waterfront houses are often unpopular with homeowners, and beach nourishment, or adding more sand to the coastline from the ocean floor, is an expensive and temporary solution.
The Sea Level Rise Viewer, recently released by the National Oceanic and Atmospheric Administration, visualizes community-level impacts from coastal flooding and sea level rise across the coastal contiguous U.S. The impact of sea level rise will be far-reaching on both the Atlantic and Pacific sides of the U.S., but sea level rise will not affect the world equally. Some of the countries impacted will be those who have contributed the least to global greenhouse gas emissions such as Vietnam, Bangladesh, and small South Pacific islands.
An analysis from Carbon Brief found the U.S. was responsible for releasing over 500 gigatons of carbon dioxide equivalent since 1850, or 20% of the world's historical total. Other major emitters include China (11%) and Russia (7%). As human activity releases greenhouse gases into the atmosphere, their heat-trapping characteristics fuel the warmer weather that causes sea level rise.
Ocean water naturally expands with warmer temperatures. Along with meltwater from shrinking Arctic sea ice and glaciers pouring into the world's oceans, global mean sea levels increase. Emissions currently in the atmosphere mean sea level rise can't be stopped, but lower emissions scenarios can slow its pace.
Using data from the National Oceanic and Atmospheric Administration's sea level rise technical report, released in 2022, Stacker identified projected sea level rise by 2050 for 40 cities in the U.S. The report identifies five sea level rise scenarios based on changes by 2100 from 2000 levels. They are low (an average of 1 foot globally), intermediate-low (1.6 feet), intermediate (3.3 feet), intermediate-high (4.9 feet), and high (6.6 feet). For each, projections under low, medium, and high emissions scenarios are included. Stacker focused on each emissions scenario for low, intermediate, and high sea level rise.
Unlike most places on this list, cities in Alaska are seeing falling sea levels, as its land is actually rising with shifting tectonic plates. Read on to see where major coastal cities in the U.S. stand.
