Rising sea levels could submerge 316 towns and cities

News and analysis by Dan Telvock, Investigative Post's environmental reporter

There’s enough greenhouse gas emissions in the atmosphere to raise the sea level in North America by more than 4 feet and flood hundreds of coastal cities and towns at high tide.

When the submersions could happen is unclear but that’s the conclusion of Ben Strauss, a scientist with Climate Central, a nonprofit group of scientists and journalists who report on the world’s changing climate. Strauss predicted the sea level rise using a study from Anders Levermann, of the Potsdam Institute for Climate Impact Research, who found that every degree of global warming caused by carbon pollution equals 4.2 feet of sea level rise in the long run.

The dismal interactive map above shows how much the risk grows for the country if the current trend of increasing carbon pollution continues.

Here’s where my jaw dropped:

By the end of this century, if global climate emissions continue to increase, that may lock in 23 feet of sea level rise, and threaten 1,429 municipalities that would be mostly submerged at high tide. Those cities have a total population of 18 million.

Stephen Vermette, a climatologist and professor of geography at Buffalo State College, reviewed the information and said his initial thoughts are that the water level projections are somewhat dramatic.

“I think that is their purpose, to shock people to a realization that sea levels will continue to rise, even if CO2 levels are capped,” he said. “I think what the authors are trying to do is warn people that higher sea levels can happen and maybe we should start planning for it.”

Florida is most at risk, followed by North Carolina, Louisiana and New Jersey.

Under current trends, by 2030 there could be 38 cities and towns in New York threatened by locked in sea level rise. Those communities, which include Bellmore, Freeport, Long Beach and Oceanside, are home to some 336,000 people.

By 2100, at least 121 cities and towns in New York are threatened under current trends, according to Strauss.

With deep emissions cuts and carbon removal from the atmosphere, he said, the sea level rise could be limited to about 7.5 feet. This would reduce the number of threatened coastal towns and cities by several hundred.

Strauss says:

“The coastal resilience measures that global cities are beginning to weigh and implement cannot be seen as solutions to a fixed problem, but rather as first steps in a long journey. The current trend in carbon emissions likely implies the eventual crippling or loss of most coastal cities in the world. However, within a rapidly closing window, deep and rapid cuts in carbon pollution may have the potential to avert this fate.”

Vermette, who also coordinates the Meteorology and Climatology program at Buffalo State, said temperatures today are about 1.5 degrees above preindustrial temperatures, resulting in roughly 8 inches of sea level rise.

“The big question is whether the rate of sea level rise will increase over time. Will that increase always be a linear increase?” Vermette said.

“The numbers given by the article and shown on the map are certainly at the upper end of projections, but even the slower increase will have impacts, especially when linked to storms and high tides.”