Sea level projected to rise a foot on US coasts by 2050

Sea levels along U.S. coasts are projected to rise up to a foot between now and 2050, an increase equivalent to the rise seen in the past century, according to a report released Tuesday by the National Oceanic and Atmospheric Administration (NOAA).

The NOAA projected sea levels will increase 10 to 12 inches, with regional variations, over the next three decades. The increase is projected to be highest along the Gulf Coast, where the report expects an increase of 14-18 inches, followed by 10-14 inches along the East Coast. On the West Coast, NOAA projected an increase of 4-8 inches, while the Caribbean is projected to see a rise of 8-10 inches.

During the 30-year period described by the report, “moderate” flooding will become an average of 10 times as commonplace as it is now. NOAA defines “moderate” flooding as more severe than “minor” flooding, typically entailing actual damage rather than nuisance. Under the NOAA projection, moderate flooding events will occur up to four times on average annually by 2050, compared to minor events, at three events a year.

Major flooding events, meanwhile, will occur at an average of 0.2 events annually, a five-fold increase from the current average.

Based on current greenhouse gas emissions levels, NOAA describes it as “increasingly likely” that sea levels along the coast will rise up 2 feet by the end of this century. Lack of action on future emissions increases could mean an additional five-foot increase in sea levels, according to the report.

Keeping temperature increases to the Paris Climate Agreement’s goal of 2 degrees would mean a 50-50 chance of sea levels rising more than 2 feet by the year 2100, according to NOAA. However, if the temperature increase goes as high as 3-5 degrees, the sea-level rise could be as high as three feet, according to the administration.

“This new data on sea rise is the latest reconfirmation that our climate crisis ⁠— as the President has said ⁠— is blinking ‘code red,’” White House climate adviser Gina McCarthy said in a statement. “We must redouble our efforts to cut the greenhouse gases that cause climate change while, at the same time, help our coastal communities become more resilient in the face of rising seas.”