New York Under Water: Sea Level Change This Century

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At the end of September 2009, renowned climatologist Stefan Rahmstorf spoke to an international climate change conference in Oxford, England. Rahmstorf is a respected authority specializing in analysis of ice melt and sea level changes. He and other climate scientists made this startling announcement:

A rise of at least 2 meters (~6 foot) in the world’s sea levels is now virtually unstoppable.

Sit with that for a moment.


No matter what we do now to rein in greenhouse gases, the processes that initiate significant sea level change are already underway. A tipping point in the ice melt processes has been reached. The best outcome, said Rahmstorf, would be that after temperatures stabilized, sea levels would only rise at a steady rate “for centuries to come,” and not accelerate. This assumes we can halt global warming after about 1.5 degree C increase.

Realistically speaking, though, given political issues and climate change denial resistance from the various ostriches on the scene – the much more likely scenario is that humans collectively will not be able achieve the 1.5 degree C limit, in which case the rise in sea level will be much more rapid.

Rahmstorf’s best guess is a one meter rise this century, assuming three degrees warming, and up to five meters over the next 300 years. This and other estimates are also affected by unknown variables such as what will transpire with large sheet ice at the poles, and transient sea rises, which are different from long-term global sea levels. Should the climate heat up more than that, or sheet ice or transient events occur, it is easily possible to see a 2 meter rise this century, and possibly much more. (For considerable discussion on this and related points, see the excellent content at Real Climate: Climate Science from Climate Scientists.)

But the tipping point is already here, and passed. That means global processes are underway with their own inexorable march towards ever more melting ice and rising seas. This will proceed at its own pace, as inevitable and unstoppable as the rising tide.

This is not a distant eventuality, but a sea change (literally) whose effects we will see within our lifetimes. By 2050 certain populated coastal areas will be significantly impacted by this impending change in sea level. It is no exaggeration to say entire cities will be flooded or submerged: a 2-meter sea rise will, for example, obliterate built-up urban areas in the southern San Francisco Bay, including parts of San Jose. It will submerge chunks of the Port of Los Angeles, threaten Washington D.C., and drown portions of the densely built Jersey shore and industrial New York waterfronts. Low-lying coastal islands off the Carolinas, Florida, and along the Gulf Coast will simply vanish.

Most people have not even begun to contemplate (much less plan for) the real-world consequences of such a fantastic change in the world as we have known it.

Submerged New York: scene from A.I. (2001)

Part 2 in this series:  What Does a 2-Meter Sea Rise Look Like?

Part 3 in this series:  Global Warming in Science Fiction


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Yeah, it’s definitely sobering. It’s very hard to get people to understand that the lag time between change and climate effect is ~50 years, so even if we stop emitting any CO2 into the atmosphere right now, it’ll be 50 years before that produces a measurable change in the rate of warming.

On the bright side, my home on a peninsula in Maryland is 61 feet above sea level. If my granddaughter keeps the house she may have a nice waterfront property. (The water is currently about half a mile away.)

Rahmstorf says (in a very science-fictional observation) that we don’t have the technology or know-how needed to remove enough carbon from the atmosphere to seriously slow the ice melt. Looks like we’re stuck on Mr. Toad’s Wild Ride for a while.

Your place in MD sounds delightful. Good thing it’s in a lofty place. Be sure to check out the flood map link in my next post in this series (it will be online 10/30 by noon), and you can see how various degrees of sea level rise will affect your property, or the nearby shore-line.

[…] This post was Twitted by felecin9v […]

well i heard that there is more then a 50 percent chace that global warming does NOT excist. this is just something i have to do in class

I don't plan to debate climate science in this blog. There are plenty of other places on the web for that. But it is worth noting that the vast majority of reputable climate scientists have a consensus that global warming is occuring and anthropogenic causes are accelerating it. See… for a summary of relevant data.

[…] Deborah Teramis Christian describes what exactly that will (not might) look like: This is not a distant eventuality, but a sea change […]

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