Climate-change-induced sea level rise is happening faster along the U.S. East Coast than elsewhere in the world, with New York and Boston straight in the water’s pathway, the U.S. Geological Survey (USGS) says in a new study.
Scientists analyzed data on tide levels from throughout North America and found, to their surprise, that sea levels along the 600 miles from Cape Hatteras, North Carolina, to Boston rose an average of two to 3.8 millimeters annually from 1950 to 2009, National Geographic reported.
The study was published June 24 in the journal Nature Climate Change. Although the signs were not necessarily attributed to global warming, it does not help when added to the increases already expected from climate change, National Geographic said.
In New York City, for instance, the team extrapolated that sea levels could rise by 7.8 to 11.4 inches by 2100 in addition to the three feet it is already expected to rise globally by that time due to climate change, the magazine said. In contrast, the world’s oceans rose between 0.6 to one millimeter annually over the same period, the magazine reported.
“The first thing people will see from this is an increase over the next few decades in the low-level coastal flooding that occurs now with wintertime storms,” said Peter Howd, an oceanographer contracted with the USGS and one of the study’s lead co-authors, to National Geographic. “Eventually you’ll see coastal flooding events three to four times a year instead of once every three to four years.”
The researchers couldn’t tell what made the U.S.’s East Coast more vulnerable, National Geographic said, and it’s not clear what if any role human activity plays. “This could be part of a natural cycle maybe 100 to 200 years long. Or not,” said Howd. “We need more data over years to help build climate models and greater understanding.”
The team is also looking at other potential sea-level-rise hot spots, USGS study co-author Kara Doran told National Geographic. For instance, reported the website PopSci, San Francisco International airport could flood within the decade. This was based on a study soon to be released by the National Academies Press, Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future. Here the author of that study, Gary Griggs, explains the mechanics behind the west coast rise and sea-level rises in general.