Hurricane Sandy and Sea Level Rise in New York and New Jersey

First, my sympathies to the folks in the Northeast who are suffering from the after-effects of Hurricane Sandy. Watching CNN's breathless coverage of the flooding in New York and New Jersey, I got intrigued by the question of sea level rise in those regions. After all, one of the concerns about man-made global warming is that there will be a significant increase in sea level over the course of this century. The National Oceanic and Atmospheric Agency actually offers this data online. Below are the charts for the gauges at Battery Park in Manhattan and Atlantic City in New Jersey.

The mean sea level trend is 2.77 millimeters/year with a 95% confidence interval of +/- 0.09 mm/yr based on monthly mean sea level data from 1856 to 2006 which is equivalent to a change of 0.91 feet in 100 years.

The mean sea level trend is 3.99 millimeters/year with a 95% confidence interval of +/- 0.18 mm/yr based on monthly mean sea level data from 1911 to 2006 which is equivalent to a change of 1.31 feet in 100 years.

Even as sea levels around New York City have been rising, the actual land area has been expanding due to landfilled areas. The 1865 Viele Water Map below shows the areas that had been filled in by that time.

And below is a map of the area that the city government of New York ordered to be evacuated - orange and yellow mark the areas evacuated.

A closer look at the lower Manhattan evacuation zones is below.

Some interesting correlations, yes? Instead of retreating from the rising sea, people in New York City built up more land. Since sea level rise is ongoing, and may be exacerbated by man-made global warming, more and better defenses like a sea barrier at the Verrazano Narrows and the East River will need to be developed. One thing for sure, the federal government should stop subsidizing flood insurance. Go here for a fascinating set of intereactive maps that show how the shoreline of lower Manhattan has expanded since 1660.

Comments

[R C Dean]

What those charts show me is a steady increase since, what, 1850?

How that correlates to global temperatures and industrial CO2 is a mystery to me. But I suspect it doesn't. At all.

[Jersey Patriot]

The global average temperature has risen about 1.5F since 1870. Since 1950, it's risen about a degree. The rise is almost certainly due to GHG emissions. The Sun is not brighter than 1950; it's actually a bit dimmer. Moreover, GHG warming follows a specific pattern: it's not just a generic "warming", but a kind of warming whose pattern can be studied.

Not surprisingly, a warmer Earth tends to have less ice, which means more ocean. Hence, the sea level rises.

Local factors can change how much the sea level rises, of course. Scandinavia is not seeing a real rise, because the land is still "bouncing back" from the weight of the glaciers in the Ice Age. By contrast, the US East Coast is rising more quickly than most other places (though rising sea level wasn't really the problem with Sandy).

[OldMexican]

Re: Jersey Patriot,

Not surprisingly, a warmer Earth tends to have less ice, which means more ocean. Hence, the sea level rises.

The Antartic ice is increasing.

Local factors can change how much the sea level rises, of course.

It is MUCH easier that the local sea level rises due to the restriction in the flow of an important river than because of "ice melts."

Besides this, Sandy wasn't particularly potent, Cat 1 hurricate at most. What happened was that the moisture-carrying cold front from the north coincided with Sandy to deposit more water than what the storm brought.

But "weather" is not "climate" - right, JP??? Or only when it suits the AGW millenarists?

[Death Rock and Skull]

Sea level measurements can be done geodetically, which means changes in land level would have nothing to do with actual change in sea level. So Scandinavia is doing it wrong.

[BoscoH]

This is where I see the dishonesty of pinning the disaster on "global warming". Sea level rise in past century probably accounts for 20% of the damage, at most. The other 80% is people putting themselves in more danger.

On the other coast... South of Los Angeles. There was a time when new beach homes in Corona del Mar almost couldn't be given away. My grandfather was a roofer in SoCal, and did a whole bunch of new homes there in the 60s. He had a chance to buy a couple with full ocean views dirt cheap and couldn't imagine that he'd want to live there or that they'd be a good year round investment. Sure, they might rent out in the summer months. Fast forward to 1991. A friend bought one of those homes for $1.6M. Fast forward to 2007. He tore it down, built a friggin concrete mansion that has a 5-floor elevator at one spot, and sold for $10M.

These areas of interface between land and sea are inherently dangerous on occasion, and yet our value of them and desire to be near them has skyrocketed in the past few decades. That's the bigger problem here, and one that people who value being near the coast will deny more fervently than the ant-warming crowd.

[Ken Shultz]

And yet people adapt.

It's often that they try to build the house in their head instead of the house they should--given whatever dangers are lurking out there.

People in Belize build their houses on stilts, so when the hurricanes come through--and the inevitable flooding comes in--they'll be high and dry on what amounts to a pier.

People who live South of Palos Verdes, on Portuguese Bend, build their homes on stilts that absorb the shock of practically non-stop seismic activity...

Homeowners can and do adapt. Sometimes it's the local zoning ordinances that are getting in the way. If you tried to build a house on pier like stilts on the New Jersey shore, it wouldn't surprise me if the local city wouldn't let you for aesthetic reasons.

[BoscoH]

Exactly. And I'm certainly not saying that we should not live near coasts and we should change what we like in order to cut down on effects of these kinds of disasters. I think we need to get the mental accounting right. High costs of doing wonderful are just fine if we assign them right.

[Tulpa (LAOL-PA)]

People in Belize build their houses on stilts, so when the hurricanes come through--and the inevitable flooding comes in--they'll be high and dry on what amounts to a pier.

People used to do the same in Florida in the pre-FEMA days. Now they're building the same kind of house you'd build in Minnesota.

[Ken Shultz]

Exactly.

That's moral hazard at work.

[Almanian's Evil Twin]

Gummint flood insurance, FTW, bitches!

[Brett L]

Uh. No. That's not true. After Andrew, the building codes are pretty strict on houses within a certain distance from the shore. See here. Since instituting a statewide building code system in 2001, all new construction also requires hurricane straps and other things designed specifically to minimize the likelihood of major damage in hurricanes.

[Brett L]

Whoops. Lost a sentence before the link: All new habitable building construction seaward of a certain point along the coast is required to be elevated above the 100 year storm surge level.

[Isaac Bartram]

Actually Monroe County (The Keys) required that for years.

It actually didn't require raising the building up to the height that most people do. In fact some people just do it with about six feet of fill.

The reason so many Keys houses are on high stilts like they are is that people like to use the space underneath and it doesn't cost all that much more to add a few more feet when you're already going to the expense of pouring reinforced concrete columns.

[Jersey Patriot]

The real contribution of AGW wasn't sea level rise. Instead:

1. A warmer ocean has more energy, so Sandy picked up extra energy in the Atlantic that it wouldn't have otherwise had.

2. Sandy was pushed to the US mainland by a spectacularly powerful high pressure system near Greenland, a very low chance event for late October. The strength of the high pressure system is probably related to Arctic sea ice loss.

[OldMexican]

Re: Jersey Patriot,

1. A warmer ocean has more energy, so Sandy picked up extra energy in the Atlantic that it wouldn't have otherwise had.

Right. And when it is pointed out to the AGW millenarists that certain years the hurricane seasons were much milder, the standard response is "Weather is not climate!"

Except when it is. Right, JP???

[Ken Shultz]

I keep trying to dig up a post that (I think Mr. Bailey may have put up years ago?) about how Tokyo has been effectively dealing with rising sea levels--"effectively" because Tokyo's elevation has continuously dropped due to seismic activity over the years.

[Ron Bailey]

KS: What a memory! Due to subsidence, Tokyo has coped with the equivalent of a 15 foot sea level rise.

[Ken Shultz]

Thanks for that link!

Even with the new and improved archives, it's sometimes hard to find what I'm looking for.

[The Late P Brooks]

Instead of retreating from the rising sea, people in New York City built up more land.

That was in the Dark Ages, before we learned to live in harmony with nature. Won't somebody think of the slugs?

[Killazontherun]

You mean the slugs on the back of the necks of environmentalist? Yes, but their hosts are too far gone to be saved.

[Tim]

DO what you want. just don't ask me to pay for it.

[Rasilio]

Off topic but don't these maps basically disprove the central tennant of Georgist economic theory, that land can be neither created or destroyed?

Seems to me that they have created quite a bit of land in New York.

[The Late P Brooks]

don't these maps basically disprove the central tennant of Georgist economic theory, that land can be neither created or destroyed?

Don't high rise buildings pretty much do the same thing?

[Rasilio]

Not really, they would just allow more efficient use of the plot of land under them.

This however is creating new land where the previously was none. Another way to do this would be to build any sort of ship and in the future any sort of space habitat.

[Archduke Pantsfan]

So when you refer to "subsidizing flood insurance' does that refer to the government paying part of the monthly premiums, giving money to the insurance companies to help cover the cost of claims, or supplementing property owners with additional money on top what they receive in claims compensation?

[The Hammer]

Yes.

[Isaac Bartram]

Flod insurance in the US is sold by an agency of the US government. There is fo all practical purposes no private flood insurance.

The fact that premiums for private flood insurance would be prohibitively high is seen by Toady and his ilk to be an example of "market failure." Of course, it is not. It's acually an almost perfect example of the market working exactly the way it should.

The premiums for federal flood insurance are far below what they should be for the risk.

So, in a way, the answer is "all of the above."

[Death Rock and Skull]

If they are going to fill in along the shore, they should probably pile up the material slightly higher.