Sustainability Climate Change

Sea-level rise is accelerating along US coasts


Story at a glance

  • The report found sea-level rise accelerated at higher rates in 2019 than in 2018.
  • The acceleration of sea-level rise was highest along the East and Gulf Coast.
  • The National Oceanic and Atmospheric Administration has said if greenhouse emissions are not reduced, sea levels could rise 8.2 feet from 2000 levels by 2100.

The pace of sea-level rise along a large part of the the U.S. coastline is continuing to accelerate, according to a new report

Researchers at William and Mary’s Virginia Institute of Marine Science (VIMS) released their annual sea-level “report card” Monday, which measures tide gauges at 32 locations along the U.S. coast. The report includes more than 50 years of water-level observations, from January 1969 through December 2019. 

The report found that at 25 of the 32 sites, sea-level rise sped up at higher rates in 2019 than it did in 2018. 

“The key message from the 2019 report cards is a clear trend toward acceleration in rates of sea-level rise at 25 of our 32 tide-gauge stations. Acceleration can be a game changer in terms of impacts and planning, so we really need to pay heed to these patterns,” Virginia Institute of Marine Science emeritus professor John Boon said in a statement

The acceleration of sea-level rise was highest along the Gulf Coast. Grand Island, La., saw a nearly 8 millimeter yearly increase, which is double the global average. Galveston and Rockport in Texas also saw significant increases. 

Researchers say the current acceleration in sea-level rise began around 2013 or 2014, and is likely associated with ocean dynamics and ice-sheet loss. In 2019, rates of sea-level rise accelerated at all 21 of the stations studied along the U.S. East and Gulf coasts and at seven of the eight monitored stations along the West Coast. 

“Although sea level has been rising very slowly along the West Coast, models have been predicting that it will start to rise faster,” VIMS marine scientist Molly Mitchell said. 

Globally, the sea level has increased about 8 inches since 1880. In the past 100 years, it has climbed about a foot or more in some U.S. cities because of ocean currents and land subsidence.

The National Oceanic and Atmospheric Administration (NOAA) has recently warned about sea-level rise acceleration, claiming that by the end of the century, global sea level could rise 8.2 feet above 2000 levels by the year 2100 if greenhouse gas emissions are not reduced. 

Heat-trapping greenhouse gases cause more land ice like glaciers and ice sheets to melt and water to expand. Scientists warn global warming will be the main driver of future sea-level rise.