Ah, once again in response to a fearmongering press release, we see the obligatory “NYC is flooded” photoshop trick.
But guess what? I’ve already debunked that photo as impossible for the time frame. More on that later after we do the math on the press release that prompted this.
First the press release, from the University of Copenhagen
Sea levels will continue to rise for 500 years
Rising sea levels in the coming centuries is perhaps one of the most catastrophic consequences of rising temperatures. Massive economic costs, social consequences and forced migrations could result from global warming. But how frightening of times are we facing? Researchers from the Niels Bohr Institute are part of a team that has calculated the long-term outlook for rising sea levels in relation to the emission of greenhouse gases and pollution of the atmosphere using climate models. The results have been published in the scientific journal Global and Planetary Change.
“Based on the current situation we have projected changes in sea level 500 years into the future. We are not looking at what is happening with the climate, but are focusing exclusively on sea levels”, explains Aslak Grinsted, a researcher at the Centre for Ice and Climate, the Niels Bohr Institute at the University of Copenhagen.
Model based on actual measurements
He has developed a model in collaboration with researchers from England and China that is based on what happens with the emission of greenhouse gases and aerosols and the pollution of the atmosphere. Their model has been adjusted backwards to the actual measurements and was then used to predict the outlook for rising sea levels.
The research group has made calculations for four scenarios:
A pessimistic one, where the emissions continue to increase. This will mean that sea levels will rise 1.1 meters by the year 2100 and will have risen 5.5 meters by the year 2500.
Even in the most optimistic scenario, which requires extremely dramatic climate change goals, major technological advances and strong international cooperation to stop emitting greenhouse gases and polluting the atmosphere, the sea would continue to rise. By the year 2100 it will have risen by 60 cm and by the year 2500 the rise in sea level will be 1.8 meters.
For the two more realistic scenarios, calculated based on the emissions and pollution stabilizing, the results show that there will be a sea level rise of about 75 cm and that by the year 2500 the sea will have risen by 2 meters.
Rising sea levels for centuries
“In the 20th century sea has risen by an average of 2mm per year, but it is accelerating and over the last decades the rise in sea level has gone approximately 70% faster. Even if we stabilize the concentrations in the atmosphere and stop emitting greenhouse gases into the atmosphere, we can see that the rise in sea level will continue to accelerate for several centuries because of the sea and ice caps long reaction time. So it would be 2-400 years before we returned to the 20th century level of a 2 mm rise per year”, says Aslak Grinsted.
He points out that even though long-term calculations are subject to uncertainties, the sea will continue to rise in the coming centuries and it will most likely rise by 75 cm by the year 2100 and by the year 2500 the sea will have risen by 2 meters.
http://dx.doi.org/10.1016/j.gloplacha.2011.09.006
Contact:
Aslak Grinsted, PhD glaciologist, Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen. +45 3532-5893, aslak@gfy.ku.dk
================================================================
First, there has been no evidence of accelerating sea level rise. Willis writes in a previous entry:
Does increased CO2 cause increased sea level rise?
Short answer, data to date says no. There has been no acceleration the rate of sea level rise. Sea level has been rising for centuries. But the rate of the rise has not changed a whole lot. Both tidal stations and satellites show no increase in the historic rate of sea level rise, in either the short or long term. Fig. 1 shows the most recent satellite data.
Figure 1. Change of sea level over time. Radar data from the TOPEX satellite. The light blue line is sea level with monthly anomalies removed. The interval between data points is usually ten days. The gray line is the 1993-2004 linear trend projected to the end of the timeline. Gaussian average using a 71-point filter. Photo taken at Taunovo Bay Resort, Fiji.
Up until about the end of 2004, there was little change in the rate of sea level rise. Since then the rise has slowed down. The average (dark blue line) does not stray far from the trend (black line) up until 1994. Since then, it is well below the projected trend (gray line). We were supposed to be seeing some kind of big acceleration in the sea level rise caused by increased CO2. Instead, we are seeing a decrease in the rate of sea level rise. So the first claim, that increasing CO2 will cause increased rates of sea level rise, is not supported by the evidence.
Note that I am not saying anything about the future. The rate of sea level rise might go up again. What we can say, however, is that there is no hint of acceleration in the record, only deceleration. The claim of CO2 induced sea level rise is false to date.
=================
Second, these guys can’t even show math that matches the claims. Since there appears to be no acceleration in the record, and the average rate is 3mm per year we get this for they year 2100, 89 years from now:
89 years x 3 mm/year = 267 mm or 26.7 cm by the year 2100
Compare that to:
Even in the most optimistic scenario, which requires extremely dramatic climate change goals, major technological advances and strong international cooperation to stop emitting greenhouse gases and polluting the atmosphere, the sea would continue to rise. By the year 2100 it will have risen by 60 cm…
Even if nature doubled the rate of sea level rise to 6 mm/year we still wouldn’t make it:
89 years x 6 mm/year = 534 mm or 53.4 cm by the year 2100
60cm by 2100? FAIL
=====================
Third let’s have a look at that photo of NYC again, since I’ve covered it before:
Below is a repost of an analysis I did on Nov 28th, 2010 on a photo from this “NYC is flooded” photoshop trick set. Guess how long it takes to get the results shown in that photo?
Freaking out about NYC sea level rise is easy to do when you don’t pay attention to history
One of the more common visual tactics used by AGW proponents to scare people into thinking that AGW induced sea level rise is a big threat is to show altered photographs and GIS models of a city near the ocean (take your pick, New York, London, San Francisco etc.). These futuristic images demonstrate what the city might look like once global warming kicks in and kicks our butt, apparently without anyone noticing the advance of the sea. Take for example, lower Manhattan, one of the more common targets. The top image is a future shock rendition from the History Channel “Armageddon Week” and the bottom image is a photo of present day reality from Wikimedia.
Scary huh? And it’s not just photos, now that most anyone with a PC can run Google Earth, there’s a veritable cottage industry of people who make sea level inundation KML files using the 3D buildings feature for major cities. It works very well to get people’s attention. But how much of a looming threat is it when compared to the reality of measured sea level rise? Let’s find out.
New York City under a 3-5 meter rise in sea-level due to global warming. Source: Inhabitat.comWill Manhattan really look like that in the future? You can even interactively freak yourself out here, at Climate Atlas, and see what it looks like in NYC when the entire Greenland Ice Sheet melts:
Gosh.
Well, I can see how people must be terrified. Just look at this plot of sea level rise at the Battery Park tide gauge from NOAA:
Yeah, it’s headed up, wayyyy up. 2.77 millimeters per year. So, to get the levels in the photo and 3D GE model shown above, we’d need to do some simple calcs.
The Google Earth 3D model is easy. It specifies a 3-5 meter sea level rise, so we’ll call it 4 meters.
For calculation purposes, we’ll assume sea level rise to be linear, and round up the Battery Park tide gauge rate to 3.0 mm per year, which puts it closer to the 3.1 mm per year measured by satellite and published at Colorado State University’s Global Sea Level Page.
4 meters = 4000 millimeters
4000 millimeters /3.0 millimeters per year = 1333 years
Now, how about the doctored image from the History Channel? There’s no reference given on the height of sea level rise on the web page, but fortunately, we have built-in yardsticks in the image. The story height of buildings in the photo can easily be estimated from the before and after photos shown at the top of this post.
I’ve selected the white building on the northeast side of Battery Park, along South St. I counted 18 stories of that building as being underwater using the hi-res image here , and I’ll estimate from other objects in the photo (like the water to pier to street height) that it is an additional 2 stories from street level there to the present day sea level (PDSL).
So what is the height of a story? The Council on Tall Buildings and Urban Habitat gives a handy guide on story height for office buildings like that one. They say that an office building like that one has a story height of 3.9 meters , so we’ll use that.
History Channel photo submersion = 20 stories
Story height = 3.9 meters
Sea Level Rise in the photo 20 x 3.9 meters = 78 meters
78 meters = 78,000 millimeters
78,000 millimeters / 3 millimeters per year = 26,000 years
26,000 years to get that? Would those buildings still be standing then? And even more important, wouldn’t we be in a new ice age by then? If we did enter another ice age, sea level would be lower, as demonstrated in this graph below. Note the level 24,000 years ago.
Image: Global Warming Art – clickThis demonstrates the folly of assuming that climate change, and hence sea level rise, is linear. As we all know, it isn’t, yet that doesn’t stop many AGW proponents from using present day measurements to project linearly into the future and then generate scary scenarios and visuals from it.
Even on the short-term, such predictions fail miserably. Take for example Dr. James Hansen of NASA GISS. Read his prediction 20 years ago about sea level rise in New York City, which I previously covered on WUWT in A little known 20 year old climate change prediction by Dr. James Hansen – that failed badly.
He said that [in 20 years]:
“The West Side Highway [which runs along the Hudson River] will be under water.(which has been “updated” now, even with the update it still fails)
Problem is, here it is 20 years later, and people still drive that highway today without the use of Jet-Skis.
West Side Highway in 2007. Image: WikimediaWhat got me started on this post was a comment left on WUWT by “Rascal”
Submitted on 2010/11/26 at 7:46 pmCopy the following address in to your browser, and observe the expansion of lower Manhattan since 1660.
http://www.racontours.com/archive/coastline_anim.php
Note that the West Side Highway (West Street) over half of the World Trade Center site, and the South Street Seaport were “under water” in 1660!
He’s right. And one thing many AGW proponents don’t consider (in addition to the non-linearity of climate) is the adaptability of humans. For readers here, I’ve taken that Flash animation at Racontours.com and made it into an animated GIF below:
Flipbook of lower Manhattan harbor and city adaptation from 1660-2004. Images from Racontours.comThey write about this historical account of lower Manhattan:
Based on our study of historical maps of Manhattan, Racontours has been able to create this simulation of the expansion of the island’s coastline. This topic is covered in both our South St. Seaport and Lower Manhattan tours, and most people are amazed at the transformation that’s taken place. Pearl St, named for the seashells that washed up there, once ran along the river. (Click here for a view of Captain Kidd’s house at the corner of Pearl & Wall Streets)
The first land reclamation was undertaken by Peter Stuyvesant upon taking over as the colony’s governor in 1646. Hoping to facilitate waste disposal and transportation, he organized the excavation of the canal along what is now Broad St. Back then, this was still called New Amsterdam, and the Dutch were great believers in canals.
By the American Revolution, the city’s population had grown to 30,000, and land had become scarce and cramped in the city center. That’s when the city began to sell ‘water lots’, wherein entrepreneurs would seek to use landfill to create additional lots for use.
The most recent landfilled area led to the creation of Battery Park City, built in the 70′s on the earth excavated from the World Trade Center’s foundation.
Based on the 2.77 millimeters per year (call it 3 mm) of current sea level rise as shown by that Battery Tide gauge, in the 344 years (1660-2004) the sea level would have risen by:
344 years x 3 millimeters/year = 1032 millimeters or 1.032 meters.
Clearly, New Yorkers have been able to stay well ahead of that 1 meter rise since the city was founded.
The next time your friends get freaked out about sea level rise, or “high water”, show them this.
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BrianH: The point of the link was to point out that these things happen over time for a variety of reasons . . .
I, personally, do not think that there is any evidence that there was ever ever, any population great enough to “suck dry” a lake in the ancient past . . . somehow altitude must have changed as all water runs down hill . . . and I could go on and on about natural variations that may have caused this . . . . Many think that the Sahara Forrest as decimated by some man made action also . . .
This is as foolish as thinking that if you try hard enough & believe hard enough or be obedient enough to “God” you can change a natural event of nature . . . this seems to be the never ending Mantra of the AGW crowd . . . .
But, it does not mitigate the fact that there are . . . catastrophic weather events, earth events, IE . . . earthquakes, volcanoes, storms, fires, floods and other events . . . that occur naturally over time . . .
Just insert the Serenity Prayer here . . . .
Hmmm, must be a UN Climate Change conference coming up.
I think Elma FUDD is onwee about sewenty yeawas old, you tweachuas twixta.
hahahahahahahahahaha……
Laurie;
population? sucked dry? You are confusing me with someone who mentioned such things. I was referring to the non-correlation of global warming with desertification.
Richard Barnes invited me here to wassup. So before I start I’d like to highlight the little common ground we have, since that is always a good place to start. So it seems that the majority of us can agree that over the 20th century:
* the world is warming
* sea level is rising
* CO2 is increasing.
I am happy that we won’t have to discuss these measured facts.
Here is the causal chain of events as I see them, and then I would be happy if you would clarify exactly which of these steps you dispute.
1. CO2 leads to radiative forcing
2. Radiative forcing leads to warming
3. Heat shrinks land based ice and expands oceans
lukewarm do not dispute any of these, but question the climate sensitivity , which is how much warming you get for a given increase in Radiative forcing. if you are a lukewarm then you should be pleased to learn that our sea level projections are completely independent of this climate sensitivity.
aslak grinsted – many thanks for providing your comment here. It is difficult for me to comment in any detail on your paper because it is paywalled. I have to base my comment on your paper’s abstract and how it is reported here.
Firstly, your paper is reported as saying that “In the 20th century sea has risen by an average of 2mm per year, but it is accelerating and over the last decades the rise in sea level has gone approximately 70% faster“. I have downloaded the sea level data from http://sealevel.colorado.edu/files/2011_rel3/sl_ns_global.txt, and the average rise in sea level over the full period (late 1992 to mid 2011, unadjusted) is 2.86mm pa [MS Excel LINEST() function]. This is only about 40% above the 2mm pa you cite for 20thC, not 70%. This alone I suspect would be enough to significantly reduce your model’s predictions.
On top of that is the fact that the rate of sea level rise has slowed significantly in recent years, not accelerated, so there would appear to be grounds to suppose that the eventual rise could be somewhat lower. Over the last 10 years the rise rate is 2mm pa [same function]. Over the last 5 years it is just under 1.5mm pa.
You claim that “our sea level projections are completely independent of this climate sensitivity“, but I think this cannot be true. Your model is forced with four different radiative forcing scenarios, which do take into account different possible CO2 emission scenarios {eg. your graph caption says “The red line can be considered to represent business as usual where greenhouse gas emissions are increasing over time.“). The CO2 concentration and forcing figures you are using are also used in climate sensitivity calculations, so even if you are not actually using climate sensitivity, you cannot be “completely independent” of it.
The important fact is that all your predictions are from a model built on assumptions about how the sea level will continue to move. To put it simply, the GIGO principle applies. Until we know what your assumptions are, it is impossible to have any confidence in your model’s predictions. Let’s face it, it isn’t real science, it’s only a model.
But there are other ways of assessing the predictions, which you describe in these terms “Sea level rise over the coming centuries is perhaps the most damaging side of rising temperature (Anthoff et al, 2009). The economic costs and social consequences of coastal flooding and forced migration will probably be one of the dominant impacts of global warming (Sugiyama et al, 2008)“. Also presented above as “Rising sea levels in the coming centuries is perhaps one of the most catastrophic consequences of rising temperatures. Massive economic costs, social consequences and forced migrations could result from global warming.” but I don’t know if those are your own words.
Well, to put the predictions into context, the sea level has risen about 120m over the last 21,000 years (IPCC report AR4 FAQ 5.1). That’s an average of 5.7mm pa, from entirely natural causes. Against this actual historical rate, your predicted sea level rise rates look very small. To use them to spread fear is frankly ridiculous, especially when taking into account that, on your figures, it is something like 500 years before the rise becomes truly significant. That means that the world’s civilisations have a period of 500 years over which to adapt to the change. When you think just how much the civilised world has changed over the last 500 years (that’s from around Columbus’ time and before Galileo, for example), I would suggest that it will be a piece of cake. The world will surely face far far more severe problems than that. Look at it this way: the average age of a house in the USA is 32 years (http://www.homeownernet.com/decorating/remodeling_classic_styles.html) – there isn’t much that won’t be rebuilt many times over 500 years.
Finally, I come back to your initial statement: “the majority of us can agree that over the 20th century:
* the world is warming
* sea level is rising
* CO2 is increasing.
I am happy that we won’t have to discuss these measured facts.“.
I would put it this way: over the 20th century, the world did warm, the sea level did rise, and CO2 did increase. But the world has warmed and cooled before, the sea level has risen and fallen before, and CO2 has increased and decreased before. All of them have changed by much larger amounts in the past, and none of them have behaved exceptionally in the 20th century. There is every possibility that the natural cycles will continue as before, so the 21st century (and later centuries) cannot be predicted by linear extrapolation from the 20th century or by any computer model which ignores the natural cycles.
BrianH: If I misinterpreted the intent of your statement, I hope you will understand . . . . I suppose that is what dialog is for . .
aslak grinsted says:
> …It seems that the majority of us can agree that over the 20th century:
> * the world is warming
Well, it warmed in the 1920s, 1930s, 1980s and 1990s, and the world was warmer at the end of the 20th century than at the beginning. So, yes, though it doesn’t seem to be warming at the moment.
> * sea level is rising
Yes, but it is rising no faster now, at ~400 ppm CO2, than it was 2/3 century ago, at ~300 ppm CO2.
> * CO2 is increasing.
Yes. More importantly, it has been rising for well over 1/2 century, with no measurable effect on rate of sea level rise. In fact, most measurements indicate there has been no acceleration in rate of sea level rise since 1900, and significant deceleration in rate of SLR over the last 70-80 years — i.e., over the period of time when the bulk of anthropogenic CO2 was added to the atmosphere.
> Here is the causal chain of events as I see them, and then I would be happy if you would
> clarify exactly which of these steps you dispute.
>
> 1. CO2 leads to radiative forcing
Yes, though to a diminishing extent. MODTRAN calculates that about half of all the warming attributable to CO2 was achieved with the first ~18 ppm of CO2 in the atmosphere. We’re now at ~400 ppm.
> 2. Radiative forcing leads to warming
Of course, but the sum total direct warming effect of the last 100 ppm of CO2 (i.e., the presumably anthropogenic part) is calculated as less than 0.3 degree. It is not at all clear that such a slight warming should be expected to measurably increase the rate of sea level rise.
> 3. Heat shrinks land based ice and expands oceans
It depends on where the heat is, but, in theory, yes.
However, the sea level measurement record at coastal tide stations indicates that the rate of sea level rise has not increased in response to 20th century CO2 and temperature increases. Models which say that the rate of SLR should have increased have thus been falsified.
Moreover, warming of the surface layer of the ocean has no effect on coastal sea levels, for the same reason that freezing and melting of floating ice has no effect: as long as the density of surface water (whether liquid, solid, or slush) is lower than the density of the deep ocean, the surface water’s displacement is unaffected by its density. Only if and when the surface warming significantly affects deeper ocean temperatures can warming of the ocean measurably affect coastal sea levels. That takes hundreds of years, so it cannot have been significantly affected by anthropogenic CO2, yet.
> lukewarm do not dispute any of these, but question the climate sensitivity , which is how
> much warming you get for a given increase in Radiative forcing. if you are a lukewarm
> then you should be pleased to learn that our sea level projections are completely
> independent of this climate sensitivity.
That is a surprising claim. If you theorize that warming causes sea level rise, then how can it possibly be true that the amount of warming doesn’t affect the amount of SLR?
Laurie Bowen the Troll wrote:
> Where’s the water? Signs of ancient lakes in China’s parched desert
> http://news.medill.northwestern.edu/chicago/news.aspx?id=190203
The video is interesting, Laurie, but how old are those trees? It seems odd that neither the story nor the video mentioned that. Surely they’ve been radiocarbon dated. So was that desert wet during a warm period or a cold one?
Durn good guestions daveburton . . . . I wouldn’t mind the answers to those myself . . .
No problem, but I’m still curious about the terms; were they yours, or did you actually read them somewhere here?
I dun know . . . I mean all the terms I use are from the English language . . . everything I know (almost) come from somewhere . . . . and I don’t think any one has a monopoly or rational (or irrational) argument . . . some assert that ‘there is nothing new under the sun!’ Don’t mean to be vague . . . but it’s the best I can say! . . . at this time . . . “in my opinion . . . .”
Fair use provisions of the copyright law allow for limited copying or distribution of published works without the author’s permission in some cases. Examples of fair use of copyrighted materials include quotation of excerpts in a review or critique, or copying of a small part of a work by a teacher or student to illustrate a lesson.. . This is what a i found somewhere.. So can i upload short excerpts of copyrighted content there?.
I’m disappointed that Aslak Grinsted has not responded.
I couldn’t help myself a while back and sent Aslak an E-mail, (Alcohol might have had a small part in it)
Got an answer!
Hi Roy
On Tue, Oct 18, 2011 at 7:13 PM,
Seriously! Why do you AGW people keep publishing this fear mongering? I do understand that you get these “results” from your “models” BUT photo shopping like that to scare the public based on “could” is absolutely discusting.
I did not photoshop anything. I co-authored a scientific article, our university sent out a press release, and the newspapers write whatever they want. It is also the newspapers who choose whatever artwork they think is appropriate. If you have a beef with that then go complain to the people who is responsible rather than going around insulting people based only on a prejudice against “AGW people”.
While I think that it is important to try to do something to avoid the worst case scenarios, then what we are trying to do is actually just providing the best possible long term projections so that efficient adaptation strategies can be devised. our point is that even in the best case we still need alot of adaptation, and we might as well start making informed infrastructure decisions now. A 1m rise is practically certain. Why not start planning for protection against that level. It wont be wasted anyway since it will also protect against natural ocurring storm surges. Also, It is just stupid to expose yourself to additional risk by ignoring what is going to happen (especially now that you skeptics have successfully screwed up the chance of a best case scenario). So, I hope that people stop developing new city parts in vulnerable regions.
Finally we highlight that the very obvious fact that there is a considerable commitment to sea level rise beyond the year 2100. This is not news, but just needs to be said so that proper measures can be taken.
Best regards,
Aslak
—
Dr. Aslak Grinsted
Centre for Ice and Climate
Niels Bohr Institute
University of Copenhagen
Julianemariesvej 30
2100 Co
Laurie Bowen Here is part of the answer Taklamaken people.
Another part is here.
Grinsted: “A 1m rise [by 2100?] is practically certain.”
It is astonishing to see such blind faith, in the face of such overwhelming evidence to the contrary. The fact is that at least 2/3 century of rising CO2, from ~300 ppm to ~400 ppm, have produced absolutely no increase in rate of sea level rise. In fact, most measurements indicate that the rate of sea level rise has slowed slightly.