Another Stephan Rahmstorf sea level scare

From the Potsdam Institute for Climate Impact Research (PIK)  another Stephan Rahmstorf scare projection, so important they couldn’t even wait for it to be put on the NCC website before sending off this press release to Eurekalert (see weblink at end of story which is DOA as of 10PM PST 6/24).

Significant sea-level rise in a 2-degree warming world

Sea levels around the world can be expected to rise by several meters in coming centuries, if global warming carries on

The study is the first to give a comprehensive projection for this long perspective, based on observed sea-level rise over the past millennium, as well as on scenarios for future greenhouse-gas emissions.

“Sea-level rise is a hard to quantify, yet critical risk of climate change,” says Michiel Schaeffer of Climate Analytics and Wageningen University, lead author of the study. “Due to the long time it takes for the world’s ice and water masses to react to global warming, our emissions today determine sea levels for centuries to come.”

Limiting global warming could considerably reduce sea-level rise

While the findings suggest that even at relatively low levels of global warming the world will have to face significant sea-level rise, the study also demonstrates the benefits of reducing greenhouse-gas emissions. Limiting global warming to below 1.5 degrees Celsius and subsequent temperature reductions could halve sea-level rise by 2300, compared to a 2-degree scenario. If temperatures are allowed to rise by 3 degrees, the expected sea-level rise could range between 2 and 5 metres, with the best estimate being at 3.5 metres.

The potential impacts are significant. “As an example, for New York City it has been shown that one metre of sea level rise could raise the frequency of severe flooding from once per century to once every three years,” says Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research, co-author of the study. Also, low lying deltaic countries like Bangladesh and many small island states are likely to be severely affected.

Sea-level rise rate defines the time for adaptation

The scientists further assessed the rate of sea-level rise. The warmer the climate gets, the faster the sea level climbs. “Coastal communities have less time to adapt if sea-levels rise faster,” Rahmstorf says.

“In our projections, a constant level of 2-degree warming will sustain rates of sea-level rise twice as high as observed today, until well after 2300,” adds Schaeffer, “but much deeper emission reductions seem able to achieve a strong slow-down, or even a stabilization of sea level over that time frame.”

Building on data from the past

Previous multi-century projections of sea-level rise reviewed by the Intergovernmental Panel on Climate Change (IPCC) were limited to the rise caused by thermal expansion of the ocean water as it heats up, which the IPCC found could reach up to a metre by 2300. However, this estimate did not include the potentially larger effect of melting ice, and research exploring this effect has considerably advanced in the last few years. The new study is using a complementary approach, called semi-empirical, that is based on using the connection between observed temperature and sea level during past centuries in order to estimate sea-level rise for scenarios of future global warming.

“Of course it remains open how far the close link between temperature and global sea level found for the past will carry on into the future,” says Rahmstorf. “Despite the uncertainty we still have about future sea level, from a risk perspective our approach provides at least plausible, and relevant, estimates.”

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Article: Schaeffer, M., Hare, W., Rahmstorf, S., Vermeer, M. (2012): Long-term sea-level rise implied by 1.5° C and 2° C warming levels. Nature Climate Change [doi:10.1038/NCLIMATE158] (Advance Online Publication)

Weblink to the article when it is published on June 24th: http://dx.doi.org/10.1038/NCLIMATE158

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UPDATE: The link above is as published at Eurekalert. The bolding of “when” is mine. Harold W points out in comments:

Correct link to the article is http://dx.doi.org/10.1038/NCLIMATE1584 [Published link lacked the final digit], or alternatively http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1584.html

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Andrew30
June 24, 2012 10:31 pm

“Significant sea-level rise in a 2-degree warming world”
So, where do we find this 2-degree warming world?
Is it one of those newly discovered distant planets?
Does it have a name, is there an image?
Is it the one with the unicorns of the one between the double-star?
Inquiring minds would like to know.

R Raymond
June 24, 2012 10:33 pm

Holy Molley. Worst case, the sea level COULD rise up to 10 feet in the next two or three hundred years. Run for the hills, it;s a disaster.
Or, maybe not.
What should I do?
Have a beer, kick back, go to work in the morning, raise my family. That’s my choice.

cartoonasaur
June 24, 2012 10:36 pm

The modern witch hunt: invent a future witch that is going to burn THE FUTURE WORLD – then save the world by burning the present economy… Weird, huh?

June 24, 2012 10:40 pm

…”semi-empirical” or quasimodo?

M
June 24, 2012 10:44 pm

Still, there appear to be some who are not embarrassed by co-authoring with Rahmstorf.
And that’s the memo.

Eric.H.
June 24, 2012 10:47 pm

” If temperatures are allowed to rise by 3 degrees, the expected sea-level rise could range between 2 and 5 metres, with the best estimate being at 3.5 metres.”
How are we going to get from 1.5mm per year to 3.5 meters in 288 years?

Geoff Sherrington
June 24, 2012 10:47 pm

Can anyone please reconcile these two apparent statements in conflict:
“One important change in these releases is that we are now adding a correction of 0.3 mm/year due to Glacial Isostatic Adjustment (GIA), so you may notice that the rate of sea level rise is now 0.3 mm/year higher than earlier releases. ” http://sealevel.colorado.edu/
“Xiaoping Wu of NASA’s Jet Propulsion Laboratory, Pasadena, California, led an international group of scientists that applied a new data calculation technique and subsequently determined that the average change in Earth’s radius is 0.004 inches (0.1 millimeters) per year, or about the thickness of a human hair, a rate considered statistically insignificant.” http://earthsky.org/earth/nasa-confirms-earth-isnt-expanding
Is it not blindly obvious that one is wrong?

June 24, 2012 10:47 pm

“Due to the long time it takes for the world’s ice and water masses to react to global warming, our emissions today determine sea levels for centuries to come.”
Everybody take a deep breath and exhale, then — my investment in beachfront property in Phoenix is looking a little shaky right now…

cartoonasaur
June 24, 2012 11:05 pm

Definition of HUBRIS: “Allowed to rise…”

June 24, 2012 11:22 pm

Climate bollocks.

James Sexton
June 24, 2012 11:22 pm

“The new study is using a complementary approach, called semi-empirical, that is based on using the connection between observed temperature and sea level during past centuries in order to estimate sea-level rise for scenarios of future global warming.”
=======================================================
What a fantastic claim! They used the plural? As in we have empirical knowledge of global temps and sea level for more than one century? No we don’t. We don’t even have empirical knowledge of our last century’s temps and we certainly don’t for our sea levels. Semi-empirical? More like more of the delusional fantasies of a dying occupation of sooth-saying.
We can’t even use our satellite date for such calculations because they keep moving the numbers around. Forget what they did with Envisat. That was just the warmup. Here’s my latest look at Jason II. It includes the last 4 screen captures I did with Aviso. http://suyts.wordpress.com/2012/06/17/jason-ii-the-changeling/ They keep moving the numbers!
How doesn’t one calculate anything when the numbers they’re using are dynamic? I’d be most interested in seeing what they used for calculating temps, and sea levels.
.

James Sexton
June 24, 2012 11:30 pm

Geoff Sherrington says:
June 24, 2012 at 10:47 pm
Can anyone please reconcile these two apparent statements in conflict:
“One important change in these releases is that we are now adding a correction of 0.3 mm/year due to Glacial Isostatic Adjustment (GIA), so you may notice that the rate of sea level rise is now 0.3 mm/year higher than earlier releases. ” http://sealevel.colorado.edu/
============================================
Lol, no, we’re not expanding!!! We’re just getting taller!! Soon, instead of being a spheroid, the earth will assume some sort of canister shape…….. because of the GIA. 😐 But, I prefer to think of it as the bottom of the oceans are getting deeper! 🙂 Others still, simply prefer to point and laugh at Colorado U.

Peter Miller
June 24, 2012 11:37 pm

I have got to start writing stuff like this, I hear they pay you very well for this type of fiction.

Ray Boorman
June 24, 2012 11:44 pm

The press releases from organisations wedded to the AGW gravy train become more sensational over time. The money must be good, because they seem to have no idea how ridiculous they appear to thinking members of the community. Fire them all & give them jobs as stable cleaners – with apologies to any muck-rakers who see this.

Neville
June 24, 2012 11:51 pm

I’ll ask again, where is that dangerous SLR coming from? Check out the graphs of “all the models” for Greenland positive and Antarctica negative for the next 300 years.
http://rsta.royalsocietypublishing.org/content/364/1844/1709/F4.expansion.html
We’ve covered 99% of the planet’s ice and 89% ( antarctica) will be gaining ice until the year 2300.
So where’s that SLR to come from again?

Rob Schneider
June 24, 2012 11:56 pm

“Due to the long time it takes for the world’s ice and water masses to react to global warming, our emissions today determine sea levels for centuries to come.”
Humm. Remind me please of the physics behind this lag? Isn’t the reaction basically instantaneous to temperature (melting ice, increase in water volume)? What causes the “long time”?

Dagfinn
June 25, 2012 12:22 am

It seems to me the sea level rise projections keep moving further into the future. Whatever happened to 2100? What an anti-climax.

Adam Gallon
June 25, 2012 12:28 am

“from a risk perspective our approach provides at least plausible, and relevant, estimates.”
Let me correct that typographical error for you Doc!
“from a risk perspective our approach provides the least plausible, and relevant, estimates.”
There, much better (Better still if I could do bold in this html thingy)

UK Sceptic
June 25, 2012 12:49 am

Potsdam? Potsdum more like. Sigh…

Paul Nottingham
June 25, 2012 1:07 am

I’m absolutely no expert but surely the seasonal variation in sea ice shows that its extent and volume can change very rapidly so that a small decline in global temperatures would lead to a fall in sea levels invalidating the statement that:
“Due to the long time it takes for the world’s ice and water masses to react to global warming, our emissions today determine sea levels for centuries to come.”
I think I trust Mark Twain more:
“In the space of one hundred and seventy-six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over one mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oolitic Silurian Period, just a million years ago next November, the Lower Mississippi River was upwards of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing-rod. And by the same token any person can see that seven hundred and forty-two years from now the Lower Mississippi will be only a mile and three-quarters long, and Cairo and New Orleans will have joined their streets together, and be plodding comfortably along under a single mayor and a mutual board of aldermen. There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.
– Life on the Mississippi”

Ian
June 25, 2012 1:11 am

Ray, did you mean UNstable cleaners?

tonyb
June 25, 2012 1:17 am

A few months ago I wrote Part 1 of ‘Historic variations in sea levels-from the Holocene to the Romans.’ It is here
http://judithcurry.com/2011/07/12/historic-variations-in-sea-levels-part-1-from-the-holocene-to-romans/
A much more comprehensive version is here.
http://curryja.files.wordpress.com/2011/07/document.pdf
It is clear that there are considerable variations in levels which may coincide roughly with warm/cool periods. We are currently around 20cm or more BELOW the levels that occurred during the Roman optimum. There are a couple of useful graphs in the article towards the end that show this. As our current temperatures are somewhat below that period it seems unlikely we will reach it (unless temperatures continue to rise strongly) although there is the considerable wild card of the pumping of water from underground sources which may affect levels in a manner that hasn’t happened in previous sea level changes
tonyb

Geoff Sherrington
June 25, 2012 1:47 am

“Limiting global warming to below 1.5 degrees Celsius and subsequent temperature reductions could halve sea-level rise by 2300, compared to a 2-degree scenario. If temperatures are allowed to rise by 3 degrees, the expected sea-level rise could range between 2 and 5 metres, with the best estimate being at 3.5 metres.”
That is the speculation.
………………………………………
The reality is that to measure thermal effects on ocean volume, one has to know the water temperature all all watery places to a fairly tight 3D grid, far tighter than anything reliably existing now for the deep oceans.
You can’t do the sums unless you know the deep ocean parameters.

KenB
June 25, 2012 1:49 am

Yawn – all depends on the BIG “IF” and THAT post normal meme now only rings a bell with “believers”

June 25, 2012 2:00 am

Eric.H. says:
June 24, 2012 at 10:47 pm
” If temperatures are allowed to rise by 3 degrees, the expected sea-level rise could range between 2 and 5 metres, with the best estimate being at 3.5 metres.”
How are we going to get from 1.5mm per year to 3.5 meters in 288 years?

With adjustments, of course.

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