Daily High-Tide Flooding Possible By End of Century


The East Coast and areas near the Gulf of Mexico could experience daily high-tide flooding by 2100, according to a recent federal report.
Even if greenhouse gas emissions are reduced, flooding is still expected at least every other day under an “intermediate low scenario,” as reported by The Washington Post. Greenhouse gas emissions help warm the climate and increase the rise of the sea level.

William Sweet, an oceanographer at the NOAA, said changes will come quickly.
“… By the time you realize there is a flooding issue, impacts will become chronic rather quickly,” he said in the Post article.
The National Oceanic and Atmospheric Administration (NOAA) report calculated the incidence of Mid-Atlantic high-tide flooding in the past 15 years. In 2000, high-tide flooding occurred three days per year on average, while the same flooding occurred six days per year five years later, in 2015.

According to the Post, similar accelerations in coastal flooding have been observed in other East Coast locations—Florida, the Carolinas, and the Northeast. In fact, the highest tides in Boston’s recorded history occurred this past winter.

Options are limited and, in the case of retreat and seawalls, costly. There’s also been talk of halting development along some coastal cities, according to a National Geographic report. Overall, hundreds of U.S. cities are expected to experience flooding due to a rise in sea level. At the time of the 2017 report, more than 90 coastal communities were already battling severe flooding, causing residents to move to other cities.


This isn’t the first time officials have feared the impacts of aggressive tidal flooding.
In 2014, The Union of Concerned Scientists released a report that predicted every-other-day flooding by 2045 in and near Norfolk, an area already plagued by near monthly flooding. The report, detailed by The Virginian Pilot, reviewed data from federal tide gauges along both the Gulf and East coasts. Most coastal towns analyzed for the report will see a tripling in high-tide flooding within 15 years and a tenfold increase within 30 years.

The Climate Science Special Report (CSSR) also paints a grim picture. The global mean sea level has risen about 7 to 8 inches since 1990, with about 3 of those inches coming since 1993, according to the report. Furthermore, nuisance flooding along many coastal areas is already 300 percent to more than 900 percent more frequent now than it was just 50 years ago, the report states.

Today’s flood will become tomorrow’s high tide,” said the late Margaret Davidson of the NOAA. Recent reports confirm her prediction.
Astrid Caldas, a senior climate scientist at the Union of Concerned Scientists, told the Post that global action and local measures to lower greenhouse gas emissions are necessary to lower the risk of increased high-tide flooding.