Climate scientists and real-estate experts have revised up their estimate for the number of recently built homes along the Jersey Shore that would be flooded by future sea-level rise and storm surge.
Climate Central, a Princeton-based research group, and the national real-estate company Zillow now estimate that 3,087 homes built between 2009 and 2017 — together worth more than $3 billion — are in a “risk zone” for the kind of flooding that is estimated to occur once a year by 2050.
That compares with 2,682 homes with an estimated value of $2.6 billion projected in an earlier version of the report only last November.
The upward revision reflects more accurate data that pinpoints the location of individual homes and their position in relation to the expected flooding — not a change in the predicted severity of global warming itself.
“What is different is the geocoding,” said Don Bain, a senior adviser to Climate Central. “The precise location of buildings has improved since last year. There’s a small change from last year’s annual flood to this year’s annual flood by virtue of having better location data.”
Building in areas that will feel the brunt
Like many other coastal states, New Jersey is continuing to develop areas that are expected to be increasingly vulnerable to higher seas and bigger storms in years to come, the report said. The state is one of four that has built homes in so-called risk zones at twice the rate of construction in its safer areas, and is one of three states that together have built some 9,000 homes in the zones since 2010.
The construction in areas threatened by climate change has come despite the devastation caused by Hurricane Sandy in 2012 and increasing public interest in sea-level rise, the report notes.
“Across the United States, coastal communities have recently built tens of thousands of houses in areas at risk of future flooding driven by sea-level rise from climate change,” it said. “That has put homeowners, renters and investors in danger of steep personal and financial losses in the years ahead.”
New Jersey provides an especially vivid illustration of the trend, according to the report. It said some 4,500 homes have been built in the zone since 2009, most likely driven by reconstruction after Sandy.
The new report, titled “Ocean at the Door: New Homes and the Rising Sea,” also predicts far greater damage from a so-called 10-year flood — one of a severity that’s expected only once every 10 years.
Under the 10-year scenario, there would be 4,524 New Jersey homes worth a total of $4.61 billion in the risk zone, the highest number among the 10 states with elevated exposure, the report said.
The Garden State also holds the two top spots in a national ranking of counties with the most houses in risk zones — Ocean and Cape May. And the two cities with the biggest housing exposure in the country are Ocean City and Beach Haven West, with 502 and 447 houses, respectively, in the 10-year risk zone, according to the report.
Possible cuts in emissions factored in
The projections are based on moderate global cuts in carbon emissions under a scenario known as RCP 4.5, as pledged but not necessarily implemented by 197 nations including the United States — at the Paris climate accord of 2016. The U.S. has announced its intent to withdraw from the pact but is not legally able to do so until the start of the next presidential term.
By 2050, it won’t make much difference to the number of vulnerable homes whether the world makes deep cuts or no cuts to carbon emissions, the report said. But by the end of the century, there’s a difference of more than 30,000 in projections nationally for risk-zone houses depending on which emissions scenario the world follows.
New Jersey can expect to lose 6,985 new homes to coastal flooding by 2100 if carbon emissions go unchecked, a number that rises to more than 280,000 if all kinds of homes are taken into account.
To curb development in the risk zones, the state should revoke Christie-era regulations based on the Coastal Zone Management Program that allowed more development in coastal flood plains, said Doug O’Malley, director of Environment New Jersey.
“Climate science has only got more alarming for our coastal communities,” O’Malley said. “It is imperative that the DEP revisit and revoke these Christie-era rules that make it easier to build and redevelop in flood plains.”
If DEP incorporated climate and flooding data into development decisions, it would be a “step forward,” O’Malley said.
Thinking in the long term
But even if officials curb new development in flood zones, the state will still be left with existing buildings that are in harm’s way, and those residents will face “uncomfortable” questions about whether their communities are viable in the long term, he said.
“It’s hard to live in communities if insurance rates truly reflect the risk that climate change is bringing to our state,” he said. “Those are uncomfortable questions to which there is really no good answer, but we can’t stick our head in the sand and pretend that climate change and sea level rise is not going to happen.”
Jeff Tittel, director of the New Jersey Sierra Club, said the state isn’t doing enough to control coastal development even though it has been buying up the most vulnerable properties through its Blue Acres program.
“We have a building boom that’s happening along the shore, and along our bays and harbors and they are all in areas that are subject to massive flooding,” Tittel said. “We are allowing all this to be built in areas that will be underwater at some point or will be subject to massive storm surge.”
The DEP did not respond to a request for comment.