These Mass. sites could be underwater by 2100 as sea levels rise, NOAA map says (2024)

With rising sea levels becoming a reality for many parts of the globe, an interactive map from the National Oceanic and Atmospheric Administration gives residents in coastal communities and further inland a sense of whether or not the land they live on will one day be underwater.

Called the Sea Level Rise Viewer, this map offers a chance to see what locations could be partially underwater in the future, as well as which communities further inland are at risk of one day being met with seawater.

By using the map, a dial on the left-hand side can be raised based on how much higher water levels can reach. Moving the dial to the top does not mean areas will be under 10 feet of water, and instead indicates the Mean Higher High Water, or MHHW, which is the average level of the highest tide.

In the first sidebar tab, labeled “Sea Level Rise,” the map shows what prominent sites could be partially underwater. If one selects Harvard University and slides the bar up and down, the viewer can see how much flooding the campus could see. This applies too with the New England Aquarium, Liberty Wharf Seaport Boston, Gloucester Football Stadium, Bas Relief Park and Plymouth Site.

Areas that are connected to the ocean are shown in different shades of blue, with darker blue indicating a greater depth, for example, according to the map.

“Low-lying areas, displayed in green, are hydrologically ‘unconnected’ areas that may also flood,” according to the map description. “They are determined solely by how well the elevation data captures the area’s drainage characteristics. The mapping may not accurately capture detailed hydrologic/hydraulic features such as canals, ditches, and stormwater infrastructure. A more detailed analysis, may be required to determine the area’s actual susceptibility to flooding.”

The next map features a similar dial on the right that indicates which years in which parts of eastern Massachusetts could start to see sea levels rise over a certain number of feet. By 2030, sea levels should remain at less than 1 foot over the current MHHW. These increases should see a jump by 2080, with the high expected to be at 4.1 feet.

By 2100, the high should reach 6.3 feet, according to the map.

By overlaying social and economic data on a map that depicts sea level rise, a community can see the potential impact that sea level rise can have on vulnerable people and businesses.

For the next map, NOAA overlayed social and economic data for communities that could see a likely impact by sea level rise and what it could have on vulnerable people and businesses. Population data relies on the 2010 census.

“By looking at the intersection of potential sea level rise and vulnerable Census tracts, one can get an idea of how vulnerable populations might be affected by sea level rise,” according to NOAA. “Dark red indicates tracts having a high vulnerability, and the lighter reds indicate decreasing vulnerability.”

Finally, the last type of map shows what NOAA called “recurrent or nuisance flooding.” Researchers had in mind that “today’s flood will become tomorrow’s high tide, as sea level rise will cause flooding to occur more frequently and last for longer durations of time.”

The maps use flood thresholds derived from a NOAA report on projected high-tide flooding along the U.S. coastline and are intended to provide “a national definition of coastal flooding and impacts for quantifying and communicating risk,” according to NOAA.

In a new report from the European Union’s Copernicus Climate Change Service, the last 11 months in a row have all seen global average temperatures reach above the 1.5 degrees Celsius threshold. This threshold could mean “ice-less” summers in the Arctic Ocean and a sea-level rise along coastal communities, possibly impacting six million people, according to the United Nations.

“Failing to curb future emissions could cause an additional 1.5 to 5 feet,” according to a 2022 NOAA report about sea levels rising, citing human-caused climate change.

To see if your neighborhood or favorite Massachusetts locations could be affected by rising sea levels, use the map by visiting NOAA’s website here.