Sea-level rise, reality

In the aftermath of Sandy, the public attention has focused on recovery efforts, as well they should be.

But sooner or later, don't be suprrised to see a sea change in the Sandy response.

The incredible storm surges have raised new concerns about the very real hazards of rising sea levels and the vulnerabilities of coastal properties.

All scare stories aside - and the ongoing and often tedious discussions regarding global warming have been full of them -- sea-level rise is real.

So far, it has been incremental, but it is happening, and minor coastal flooding has become so common that the National Weather Service this month raised the bar for its advisory criteria.

"We were becoming concerned that by issuing so many advisories they were becoming less meaningful," said Dean Iovino, meteorologist at the National Weather Service, in Mount Holly.

He said the agency was worried about the potential for "warning fatigue." The weather service now holds off on issuing advisories until the water level is expected to exceed the "minor flooding threshold" by at least 3.6 inches, he said. 

Just how much is sea level rising?

Off the Jersey coast, the rise has been about 0.18 inches annually in the last 20 years, which is faster than the global pace, roughly 0.12 inches, according to Steve Gill, at the National Ocean Service.

A small part of the rise is due to the natural sinking of the coast.

The season have been coming up since the end of the last glacial epoch, 12,000 to 18,000 years ago, but recent uptick represents an increase from the earlier rate of around 0.08 inches annually.

Iovino says that at the Shore, coastal flooding unquestionably has increased in the last several years.

While he didn't have data for every event, he did have numbers for the months in the last 30 years for which at least one flooding event had occurred in Atlantic City.

In the last five years, on average at least one such event has occurred in nine different months. In the previous 25 years, the events were occurring in fewer than five months on average.

The explanation is a simple one, says Iovino: Rising sea level.