What’s Ahead for NJ — More Tidal Flooding, More Battering from Hurricanes?

Tom Johnson | October 29, 2019 | Energy & Environment
Global warming, sea-level rise could mean devastating one-two punch for the state, with damage from wind and water costing billions of dollars

In the past four decades, the risk of tidal flooding doubled in New Jersey. Wind damage from hurricanes is no longer confined to coastal communities. By 2050, damage from flooding and wind will likely soar by $1.3 billion — possibly as much as $3.1 billion.

In a bleak assessment of New Jersey’s rising coastal risks, a new study by the Rhodium Group projects how rising sea levels and exposure to hurricane winds are increasing,  thus expanding areas within the state facing higher economic losses from those events.

The study, released on the seventh anniversary of superstorm Sandy, suggests much of the state is more vulnerable to climate change today than it was in 2012, and exposure is expected to grow in the future — even in counties as far north as Hudson and Bergen.

Gov. Phil Murphy will be holding an event today at which he’ll talk about coastal resiliency in the wake of superstorm Sandy.

By midcentury, an additional 33,000 to 58,000 buildings in the state will flood frequently, caused by so-called sunny-day flooding, or the temporary flooding of low-lying areas near the coast at least 10 days a year during full or new moons.

Increased risk of floodingCredit: Rhodium Group
The number of properties at risk of flooding during the highest annual tide has more than doubled between 1980 and today.

“What this report has done is bring things together we already know with economic models about risks,’’ said Robert Kopp, a co-author of the study and director of the Rutgers Institute of Earth, Ocean & Atmospheric Sciences.

Sea-level rise is recognized as a major issue in a state with a long coastline. Sea level is rising twice as fast in New Jersey as the global average, partly because the land also is sinking.

Since 1980, the number of homes at risk of sunny-day flooding increased about 110% affecting approximately 23,000 more buildings than if sea levels had not risen so dramatically, according to the study. Another 27,000 structures are now likely to flood at least once a year. Those counties most at risk from flooding are Ocean, Cape May, Atlantic and Monmouth, according to the study.

Increasing threats from hurricanes

More flooding risks also stem from growing evidence that the recent rise in temperatures globally not only warms oceans, but also changes the intensity, speed, total moisture and tracks of hurricanes and other major storms. It means noncoastal communities have a greater likelihood of experiencing wind damage from hurricanes than in the past.

Four decades ago, the chance that an average New Jersey home in a noncoastal part of the state would experience hurricane force winds was less than 1-in-200, or once every 200 years. Those chances have spiked to 1-in-30 and 1-100, as climate change makes hurricanes more damaging, as well as more frequent.

In addition, risk to structures from hurricane flooding is even greater. The study estimates between 62,000 and 86,000 more homes and commercial properties with a combined value of $60 billion now sit in areas with a 1-in-30 chance of hurricane flooding.

All of these factors have changed the economics of coastal risk from climate change, already having a significant impact on property values. Research by First Street Foundation suggests that tidal flooding driven by sea-level rise has already reduced home values in New Jersey by $4.5 billion.

In this case, Hudson and Bergen counties face the greatest risk of an increase in projected annual economic losses when compared with the climate of the 1980s. Hudson County could suffer up to $660 million in yearly losses from higher sea levels and changes in hurricane activity. Bergen County’s annual losses could be as high as $254 million.

“The economic losses depend upon how much economic activity is there,’’ Kopp explained. Measured as a share of economic activity, Cape May County is the most exposed, with as much as 2.6% of overall economic output affected.