“This new sea rise data is the latest reconfirmation that our climate crisis – as the president put it – is flashing ‘code red,'” said Gina McCarthy, President Biden’s national climate adviser, in a press release. “We must redouble our efforts to reduce the greenhouse gases that cause climate change while helping our coastal communities become more resilient.
The National Oceanic and Atmospheric Administration report is the first time the U.S. government has made specific predictions of sea level rise by 2050. Based on tide gauges, satellite observations, and computer models , it predicts that, on average, the coastal waters of the United States will rise between 10 and 12 inches by 2050.
It is getting even darker in recent years as the seas are likely to rise at an accelerated rate.
By 2100, scientists estimate that coastal waters to the northeast could rise between 2 feet and 7 feet, and continue up to 12 feet by 2150.
These later estimates depend much more on how much fossil fuel continues to be used and how quickly the ice sheets covering Antarctica and Greenland are melting. Little can be done to change the amount of tides that will rise over the next three decades, according to the report, given the large amount of greenhouse gases that have already been pumped into the atmosphere. .
“Obviously, we need to start planning for the challenges this will pose for Boston now,” said Rob DeConto, a climatologist at the University of Massachusetts Amherst who studies sea level rise. “After 2050, our greenhouse gas emissions will make all the difference in the world.”
Without rapid emissions reductions, DeConto noted, the planet will likely look very different over the next century.
After 2100, the seas could begin to rise an inch a year, compared to about one every eight years now, he says.
“That kind of rate of sea level rise would be beyond our ability to protect parts of the city, and parts of Boston and the Massachusetts coast would have to be abandoned,” DeConto said.
The report also revealed that rising seas over the next few years will increase the frequency of coastal flooding, even in the absence of storms or heavy rains.
Nationally, such flooding on sunny days in 2050 will likely occur more than 10 times more often than today, NOAA said.
“These numbers mean a change of just one [flooding] event every 2-5 years to multiple events each year, at select locations,” said Nicole LeBoeuf, director of NOAA’s national ocean service.
In Boston, the floods are likely to be much worse than elsewhere. A previous NOAA report found that the city experienced more high tide flooding than almost any other coastal community in the country.
In 2020, Boston experienced 11 days of such flooding, more than double the number in 2000. Within a decade, NOAA scientists predicted there could be up to 35 days of flooding from this type, and up to 95 days per year by 2050.
Boston officials said they recognize the threat and are developing plans to protect city neighborhoods from sea level rise of up to 40 inches.
Last year, after pressure from conservationists, city officials for the first time began requiring developers in designated flood-prone areas, such as the seaport, to build properties capable of withstanding such sea level rise.
“Each new report reiterates what we already know: climate change is here and requires urgent action,” said Reverend Mariama White-Hammond, the city’s chief environmental officer. “Right now, we have an opportunity to address the threats posed by climate change, while simultaneously creating a fairer and more just society.”
The NOAA report adds to a body of data showing the effects of sea level rise on the northeast. Its data is similar to the most recent report on the subject produced by the United Nations Intergovernmental Panel on Climate Change, which estimated that coastal waters in the region will rise between 12 and 15 inches by 2050. .
In 2016, DeConto’s team at UMass-Amherst found that accelerating Antarctic ice melt would disproportionately affect cities on the East Coast.
As the ice melts at the South Pole, the resulting gravitational pull on the ocean, along with gradual land subsidence in the northeast, means that Boston and the surrounding region will likely experience sea level rise. the sea about 25% higher than in other parts of the planet.
Around the same time, the Boston Green Ribbon Commission estimated that the city would experience between 7 inches and 18 inches of sea level rise by 2050.
“NOAA’s report is an opportunity to refresh the urgency of what we already know and ask ourselves if we are moving fast enough to address the threat to Boston’s people, neighborhoods and economy. “said Amy Longsworth, executive director of the Green Ribbon Commission.
The threat of flooding from major storms and rising sea levels already poses a serious threat to Massachusetts.
Already at current sea level, the state has approximately 162,798 residential properties, 12,918 miles of roads, 14,644 commercial properties and nearly 2,500 other critical buildings, such as hospitals, power plants and government offices. , which are in danger of being flooded. and become unusable, according to a report last year from the First Street Foundation, a New York City nonprofit research group specializing in flood risk.
By 2051, an additional 27,714 residential properties, 1,181 miles of roads, 2,119 commercial properties and more than 450 critical buildings will face similar risks, according to this report.
NOAA’s latest findings worry some because they portend more austere reporting in the future, as computer models become more advanced and the government launches more sophisticated satellites to monitor climate change.
“What today’s report reinforces is that what looked like a worst-case scenario before is now more likely to happen, and the conservative estimates may have been too low,” said Alice Brown, chief planning and policy at Boston Harbor Now. “Changing projections mean higher standards will be needed.”