A new study released by the nonprofit organization Climate Central warns that 3.7 million Americans are at risk from flooding in the coming decades due to rising sea levels. As part of that study, researchers have made an online tool available to simulate the effect of different levels of sea level rise on coastal populations. Vineyarders can assess their risk at sealevel.climatecentral.org/surgingseas/place/counties/MA/Dukes.

In 2007 the United Nations’ International Panel on Climate Change (IPCC) made a conservative estimate of 7 to 23 inches sea level rise by the end of the century. According to this online tool, a two foot rise would put some 766 homes and 293 Vineyard residents in jeopardy. Some studies have put the upper limit on sea level rise at over six feet by the end of the century, which, according to the Climate Central tool, would imperil 1,640 homes and 648 Vineyarders. And last week a study published in the journal Geology estimated that even limiting the world to a 2-degree Celsius rise in temperature by the end of this century, as the IPCC has recommended, would still result in a 40- to 70-foot rise in sea level, even if there were no temperature rise beyond that. But Rutgers University professor of earth and planetary sciences Kenneth G. Miller says it’s not quite time to head for the hills. “You don’t need to sell your beach real estate yet,” he said in a press release, “Because melting of these large ice sheets will take from centuries to a few thousand years.”