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Dramatic Sea Level Rise Forecast for US Over Next 30 Years


FILE - The sea level in the San Francisco Bay area has risen over 20 centimeters (8 inches) in the last 100 years. (Photo by Flickr user Nick Amoscato via Creative Commons License)

The United States is expected to experience as much sea level rise by the year 2050 as the country has witnessed in the past century, according to a report led by the National Oceanic and Atmospheric Administration (NOAA) and released Tuesday.

"Sea levels continue to rise at a very alarming rate, and it's endangering communities around the world," Bill Nelson, administrator of the National Aeronautics and Space Administration (NASA), told reporters during an online briefing. "And that means it's past time to take action on this climate crisis."

Man-made carbon emissions, however, cannot be totally blamed for the inevitable rise, according to Richard Spinrad, NOAA administrator.

"Current and future emissions matter, but this will happen no matter what we do about emissions," Spinrad said. "If emissions continue at their current pace, it is likely we will see at least two feet (61 centimeters) of sea-level rise by the end of this century along the U.S. coastlines."

With the forecast of an average sea level rise of 10-12 inches (25.4 cm to 30.5 cm) by 2050, about 140,000 homes would be at risk of being flooded about every other week, according to the report.

Forty percent of the U.S. population lives within about 100 kilometers of a coastline.

The sea level rise will intensify high tides, storm surges, coastal erosion and loss of wetlands.

"Communities now dealing with nuisance flooding will be facing more damaging floods in just 30 years' time," said Nicole LeBoeuf, director of the NOAA National Ocean Service. "Another way to think about this is that a single flooding event, one that now happens every four to five years on average, in coastal communities in the southeast United States will occur four to five times per year."

The projections in the document are based on observations from coastal tide gauges and satellite imagery.

FILE - A storm drain bubbles over as a king tide rolls into the Battery in Charleston, S.C., Nov. 15, 2020.
FILE - A storm drain bubbles over as a king tide rolls into the Battery in Charleston, S.C., Nov. 15, 2020.

Nelson, a former U.S. senator, said the current administration is taking a whole-of-government approach to confront climate change.

"Different agencies, finally, are coming together to leverage their expertise to advance our understanding and planning for the future," Nelson said.

"This new data on sea rise is the latest reconfirmation that our climate crisis — as the president has said — is blinking 'code red,'" Gina McCarthy, the White House national climate adviser, 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."

In response to a question from VOA about what the best mitigation projects for the federal government and communities would be to undertake, William Sweet, an oceanographer at NOAA's National Ocean Service, said it is all about being on higher ground.

Storm water systems will need to be examined, he explained, and "when there's an opportunity to relocate major infrastructure — schools, fire departments, energy plants — elevation needs to be considered," said Sweet, the lead author of the 111-page report.

Among the worst-hit U.S. cities by midcentury: Galveston in Texas and St. Petersburg in Florida, which are forecast to see about a 60 centimeter rise in the sea level over the next four decades.

A study published in January in monthly journal Nature Climate Change predicted the cost of damage annually by flooding in the United States could increase 26% by the year 2050, totaling more than $40 billion, and it noted poor communities would be disproportionately affected.

Early in the next century, there will be even worse trouble ahead, according to Sweet. That is when the melting ice sheets in Antarctica and Greenland are likely to send even more sea water onto distant shores.