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Coastal communities including Hampton Roads are likely to see as much sea level rise in the coming decades as they have in the past century, federal officials said Tuesday.
The National Oceanic and Atmospheric Administration released updated projections that call for an average of a foot by 2050, with regional variation because of land movement. The estimates are based on data from tide gauges, satellite observations and modeling from the United Nations’ climate change analysis.
It “confirms what we’ve known all along: sea levels are continuing to rise at a very alarming rate,” said Bill Nelson, administrator of NASA, a partner on the NOAA-led report. “It’s endangering communities around the world. ... It’s past time to take action to address this climate crisis.”
Southeastern Virginia is expected to see even more in that time frame: between 15 to 18 inches of relative rise. About a third of that is because of land subsidence, or sinking that’s ongoing as a natural response to ice age glacier melting.
Areas on the outskirts of a massive ice sheet over North America were forced upward 20,000 years ago, including Hampton Roads. Though the ice melted long ago, the surrounding land is still rising and falling. The sinking is accelerated by our removal of groundwater from underground aquifers. (Subsidence rates even across the region are uneven, NOAA’s report notes, citing research out of Old Dominion University.)
The numbers shouldn’t come as a shock. Some estimates here already call for 5 feet of sea level rise by the century’s end. Sewells Point in Norfolk has seen a rise of 17 inches since 1927, compared to about 7 to 8 inches globally.
But federal officials said this week their analysis comes with backing across government agencies and renewed confidence from the data.
[ A guide to the language we use about the environment in Hampton Roads ]
NOAA’s last technical report in 2017 similarly predicted about a foot of sea level rise — but by the end of the century. This week’s document allows more precision and speeds up the timeline, officials said during a virtual press conference.
Lower-lying areas are more at risk, added William Sweet, an oceanographer with NOAA’s National Ocean Service: “We’re not holding back tides.”
The shorter-term scenarios the data paint are also independent of any action taken on greenhouse gas emissions. Though additional warming could be curbed by reducing human-caused emissions, the course for 2050 is pretty much set, officials said.
The impacts will mean a shift in how we think about nuisance flooding, said Nicole LeBoeuf, director of NOAA’s National Ocean Service.
“So far in most places, this type of flooding has been mostly disruptive, or like an annoyance or an inconvenience,” LeBoeuf said. “However, as sea level rise continues, more damaging and disruptive flooding that today typically occurs only during a big storm will happen more regularly, without severe weather.”
The Virginia Institute of Marine Science under William & Mary also just released its annual “sea level report cards” for more than 30 coastal communities. Norfolk’s report card estimates sea levels could rise by up to 2 feet by 2050.
The sea level rise news builds on another recent report from NOAA looking at Virginia’s climate.
Temperatures have risen more than 1.5 degrees Fahrenheit since the beginning of the 20th century, with historically unprecedented warming projected in the coming one, according to the State Climate Summary for Virginia.
NOAA’s National Centers for Environmental Information in Asheville puts out the state summaries every four years to complement a 1,500-page national climate assessment, said David Easterling with the technical support unit. The idea is to home in on the evolving climate of each state, he said.
Virginia — as its residents are all too familiar — has a humid climate with very warm summers and moderately cold winters. More rain falls along the coastal, eastern portion of the state.
The 1930s and ‘50s were very warm, according to Virginia’s climate summary, but the number of hot days and warm nights has increased more consistently since the 1990s, while the number of cold nights has decreased.
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Overall rainfall has also been slowly increasing in the commonwealth, which is expected to continue.
“One of the big signals we’re seeing in the data is increased precipitation events,” Easterling said. “Virginia’s starting to see their share.”
That may seem like it would negate drought issues. But alongside increasing temperatures, droughts actually worsen. Soil loses moisture at a higher rate during more dry spells, he said.
As the atmosphere warms, it holds more moisture, and the cycle of more rain continues, Easterling said.
NOAA’s environmental information center keeps track of major disaster events across the U.S. that cost a billion dollars or more in total damage. Between 1980 and 2020, Virginia was affected by 82 of the 290 total — not the most out of all the states, Easterling said, but definitely in the upper range. The costliest of those was Superstorm Sandy in 2012, which caused severe coastal flooding from storm surge.
He said officials should work on reducing the impacts from climate change and adapting to the changes already set to continue.
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Katherine Hafner, 757-222-5208, katherine.hafner@pilotonline.com