Rising sea levels are a measure of global warming and climate change. As the oceans warmer due to the increase in global global temperatures, seawater expands and causes water levels to rise, according to NOAA. Sea level also rises when land ice, such as glaciers and ice caps, melts, adding water to the ocean.
Coastal towns in Massachusetts are increasingly struggling with this problem. The number of flood days in the state is expected to increase, according to projections by the National Oceanic and Atmospheric Administration, as damaging flooding that only occurred during storms now occurs more regularly.
And sea level rise is already happening across the world and in Massachusetts. Sea level off the coast of Massachusetts is 8 inches higher than it was in 1950, and it has accelerated dramatically in recent years, now rising by about 1 inch every eight years, according to NOAA.
Ian Sue Wing, a professor in the Earth and Environment Department at Boston University, said the world would most likely reach a average sea level rise of about one and a half feet under a high emissions and high warming scenario by the 2060s to 2080s, and, citing a IPCC Report 2019, the situation could become even more dramatic for the North Atlantic coast in the following decades.
“More worryingly, models have long shown that while we can make decisions over periods of a century, nature operates at much longer scales,” Wing wrote in an email. “Warming, heat absorption by the oceans and sea level rise will continue for hundreds of years and will be associated with the loss of polar ice caps, further increasing volumes of ocean water and heights of the sea. I can’t speculate what Boston might look like so far in the future … but it is a source of concern.
How it could play out in Boston
In Boston, where about 17% of the city was built on landfills it was once mud flats, swamps or water – the area is incredibly vulnerable to flooding and sea level rise.
According to NOAA simulations, even a foot of sea level rise means flooding in dense areas of Boston, including the Back Bay area and particularly the area surrounding the Prudential Center. Parts of Mass. Pike in Back Bay could become a flood zone, disrupting traffic.
In the maps below, the areas connected to the ocean are shown in shades of blue. The darker the color, the greater the water depth in that area. Low areas, displayed in green, are hydrologically “unconnected” areas that can also be flooded. Flooding in these areas is determined by the elevation as well as the drainage of the area.
In an extreme worst case scenario, which NOAA describes as highly unlikely, global sea level could rise to 8.2 feet by 2100. As the map shows, such a rise in sea level would inundate entire swathes of the center. city of Boston at high tide, including Back Bay, Fenway, the South End, the Seaport District, much of East Boston, and parts of Dorchester.
Parts of the city, including Faneuil Hall and TD Garden, are said to be completely inundated.
In Boston, sea level is expected to rise to nearly 16 inches by 2050, according to NOAA. Experts estimate that if immediate action was taken to tackle climate change, global sea level would likely rise another 1 foot or more by 2100.
North of the city
In addition to Boston, coastal communities like Revere and Quincy are threatened by rising sea levels, including flooding, erosion, and storm hazards.
Rising sea levels also impact coastal communities like Revere as it erodes wetlands and beaches. Wetlands, such as those found in the Rumney de Revere Marsh Reserve, are vulnerable due to their low elevation. They provide habitat for birds and fish, and the loss of coastal wetlands would harm ecosystems and remove an important line of defense against coastal flooding.
According to the Environmental Protection Agency, about a third of New England’s coastal wetlands have been destroyed as a result of human activity.
Some low-lying areas of Revere are currently vulnerable to flooding, according to NOAA’s water depth measurement, particularly near Wonderland Greyhound Park, Diamond Creek and Oak Island Park.
But as the sea level rises, water begins to encroach beyond Revere Beach and the town’s marshes would be inundated. According to the simulation, the water extends further inland, submerging some residential parts of the city.
South of town
According to NOAA projections, the low-lying areas of Quincy at risk of flooding become more extensive with the rise in sea level. The NOAA water height measurement shows that some areas of the city are already prone to flooding, especially in the Blacks Creek marshes. A stretch along Wollaston Beach, Faxon Field and parts of the Presidents Golf Course are also vulnerable.
As sea level rises, impacts are visible along the Neponset River from Quincy and in the areas surrounding Rock Island, Blacks Creek, and Wollaston Beach.
Rising sea levels are also having an impact on the infrastructure of coastal communities in Massachusetts.
A recent study found that rising sea levels pose a threat to the Massachusetts Bay Transportation Authority’s rail network for the next 50 years, with the potential to flood large portions of the system and sever critical ties. The report’s authors warned that the system must take drastic action to fortify its coastal infrastructure against the realities of a warming planet.
As sea levels rise and flooding increases, homes in Massachusetts will also face an increased risk of damage. A report found that in Boston, where more than 3,000 properties per year will face a substantial risk of flood damage, those losses are expected to exceed $ 62 million per year in 30 years, or 75% more than today.