The 500 year FUD about sea levels

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

The graph shows how sea levels will change for four different pathways for human development and greenhouse gas pollution. The green, yellow and orange lines correspond to scenarios where it takes 10, 30, or 70 years before emissions are stabilized. The red line can be considered to represent business as usual where greenhouse gas emissions are increasing over time. Credit: Aslak Grinsted

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.com

Will 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 – click

This 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.

File:West Side Highway 008.jpgWest Side Highway in 2007. Image: Wikimedia

What got me started on this post was a comment left on WUWT by “Rascal”

Copy 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.com

They 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.

92 thoughts on “The 500 year FUD about sea levels

  1. Year 2100 is 89 years from now, no big deal about the results, but you might want to fix the typpo :)

    REPLY: It was fixed before your comment was completed, noticed it right after posting, but thanks – Anthony

  2. I like how they introdice the report by saying:
    “…We are not looking at what is happening with the climate, but are focusing exclusively on sea levels”

    Then the very first projection?

    “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.”

  3. According to measurements, the difference between the earth reference and the average sea level in NYC will be 28 cm more over the next 100 years… regardless of what humanity does.

    1) How much is the earth reference subsiding?
    2) How can this be any different than the planetary levels?
    3) What does this have to do with Human activity?

  4. We live in a dynamic world.

    Pleistocene climate was marked by repeated glacial cycles …
    Each glacial advance tied up huge volumes of water in continental ice sheets 1,500 to 3,000 metres (4,900–9,800 ft) thick, resulting in temporary sea level drops of 100 metres (300 ft) or more over the entire surface of the Earth. During interglacial times, such as at present, drowned coastlines were common, mitigated by isostatic or other emergent motion of some regions.

    http://en.wikipedia.org/wiki/Pleistocene

    The Bering land bridge was a land bridge roughly 1,000 miles (1,600 km) wide (north to south} at its greatest extent, which joined present-day Alaska and eastern Siberia at various times during the Pleistocene ice ages … The grassland steppe, including the land bridge, that stretched for several hundred miles into the continents on either side has been called Beringia. It is believed that a small human population of at most a few thousand survived the Last Glacial Maximum in Beringia.

    http://en.wikipedia.org/wiki/Beringia

  5. These geniuses do not imagine that small adjustments over 100s of years will be made, almost transparently, such that sea level change will be a non-issue.

    Just as Battery, NY saw 45 cm in 160 years, it is fine. Every time a pier, sea wall, or dock is rebuilt, which they will be many times over 500 years, small adjustments are made.

    It should be a crime to abuse science and misinform the public, particularly as there is a monetary gain to be had by panicking people into supporting bad policies which always seem to benefit somebody behind the scenes.

  6. This is the usual “Sea level rise porn of the week”.
    A simple look at Envisat measurements, the most precise to date altimetry satellite, the rate is barely 1.5mm/y.

    EOM

  7. I must be missing something. The Hansen article that you quote and link in the above article says 40 years not 20 years! The real problem is that the AGWs let something other than science control what they say. Dr. George Abell said that,” sometimes we take ourselves to seriously.” They allow what they want to see be what they believe.

  8. Some cities are sinking. Venice (-0.5 mm/y), New Orleans (-0.25 mm/y), and Amsterdam (-0.2 mm/y) have not been abandoned.

  9. But sea levels can not rise forever, there’s only so much water and clouds will be wanting their quota too.

  10. Do you not think that the sea level rise is more of a worry for the likes of place that receive a tidal surge during a cyclone, 60cm might make a large difference to places like Burma and Bengal.

    REPLY: So might tides which can be as large or larger. Shall we then modify the orbit of the moon to prevent high tides? It is about as plausible as the claims on CO2 emissions equating to sea level – Anthony

  11. blockquote>higley7 says:
    October 18, 2011 at 9:38 am
    These geniuses do not imagine that small adjustments over 100s of years will be made, almost transparently, such that sea level change will be a non-issue.

    Just as Battery, NY saw 45 cm in 160 years, it is fine. Every time a pier, sea wall, or dock is rebuilt, which they will be many times over 500 years, small adjustments are made.

    It should be a crime to abuse science and misinform the public, particularly as there is a monetary gain to be had by panicking people into supporting bad policies which always seem to benefit somebody behind the scenes.

    You mean we won’t just wake up one day and find NYC under 20 feet of water? The Peak Oil people think that’s what going to happen with oil — one day we won’t have any more oil but we won’t realize we’re running low until the last Hummer is filled from the last drop of gas from the last Texxon-Mobile-Shell-BP-Total-Chevron-Big-Oil convenience store.

    Instead, if sea levels rise as predicted, people will notice the gradual changes and adapt. Wow!

  12. If you go to the top of the Prudential Tower in Boston, they have a very nice narrated display that shows how the city has grown since 1630. The original tiny city on the Shawmut peninsula is now quite far from the Atlantic. The airport is on Governer’s island, which is island no more, and Deer Island, now home to a huge waste treatment plant, was once separated from the mainland by a channel big enough for naval battles during the Revolutionary War. Sea level rise just can’t keep up with those darned people.

  13. So, essentially, in the hippie reality, rising sea levels would just bring NYC back to 17th century normal level. Question then becomes, why don’t the crazy climate communist hippies want to go back to what was normal land levels for NYC?

  14. Sir…..I have seen studies in which Antartica and Greenland, when melted, increases sea
    level by five meters. And then from where comes the added water..?

  15. 26,000 years from now the earth will be sliding into its next ice age. Milankovich cycles and all that. Should cancel out the CO2 influence (if there is much).

  16. Zac makes a good point, if all the world’s glaciers and both ice caps did melt completely, it must be possible to calculate what the sea levels would be. With no more ice available, presumably that would be the upper limit. It is also relevant that if it really got warm enough to melt all this ice, Greenland, Antarctica and quite a lot of areas of Canada and Russia that are too cold at present would then become habitable. As this big melt is going to happen very gradually, surely people will just slowly migrate northwards.

    @Allan M
    Very good point, he was a very clever man.

  17. I recall seeing a fairly long term graph showing the peaks and troughs of the sea level. The height/depth at the various glacial maximums and minimums seemed fairly consistent. Currently we are near the top of such a peak and so I’d expect the sea level “rise” to taper off in short order and perhaps even reverse.

    I simply don’t think, barring massive climate change, much more water will be freed or up much more thermal expansion will take place in the coming centuries. The pattern simply doesn’t show it.

  18. What a brilliant, lucid, readable essay. For me, it encapsulates Anthony’s genius. It includes a “knock down” criticism of a pal-reviewed article that should never have been published by a reputable scientific journal and a nice healthy dose of natural history. Who knew that Pearl Street was that close to the river at one time?

    As for the publishers of the article, would you please find a good dictionary and look up that good old Scandinavian word ‘shame’? As for the authors, would you please find a math text from the second year of grammar school and study it thoroughly?

  19. Speed says:
    October 18, 2011 at 9:35 am
    “We live in a dynamic world.”

    According to Warmista, human evil caused the dynamism and must be reigned in through totalitarian government. Then we can return to The Golden Age. Just ask any communist.

  20. When I first started looking into this AGW business a few years ago, one of the first things I ran into was a pdf written by a California geologist. The pdf is long gone as are my notes (an old dead machine) but he pointed out, among other things, the high stands visible in CA from sea levels of times past. He said that before the next ice age the sea level should be a good 30-40 meters higher than it is today.

    So the alarmists are taking something that will happen no matter what we humans do or don’t do and turning it into a humongous scary story.

  21. 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.

    Wow! These guys presume to know what type of power supply we will have 500 years from now. Let’s ask Juan Ponce de Leon, who had not yet sailed from Spain to explore Florida, what our industry would look like.

  22. wanting their quota too.

    “SteveE says:
    October 18, 2011 at 10:23 am
    Do you not think that the sea level rise is more of a worry for the likes of place that receive a tidal surge during a cyclone, 60cm might make a large difference to places like Burma and Bengal.

    REPLY: So might tides which can be as large or larger. Shall we then modify the orbit of the moon to prevent high tides? It is about as plausible as the claims on CO2 emissions equating to sea level – Anthony”

    Anthony,

    Won’t need to change the Moon’s orbit as it is presently receding at about 23.6 miles per million years. As it does its tidal effect is reduced. Of course that recession is at the present rate which is also decreasing so it may take even longer to have any noticeable effect. Let’s see, gravity is reduced by the square of the distance……..Someone better at math than I will need to work out the tides. But all the same, CO2 is probably similar in its ability to have any effect upon our planet.

  23. re : 78m sea level rise

    A back-of-the-envelope calculation I did a few years ago indicated that even if every single last gram of ice on the planet melted there still wouldn’t be enough to raise the oceans by 78m. I seem to recall around 16m was the max. That calculation only considered current sea & ocean area and didn’t allow for sea area increasing due to encroachment onto low lying land.

    Don’t have those figures anyway but 16m fits in well with the 3-5 meter rise from melting the entire Greenland icesheet mentioned in the article.

    Mike (whose house is close to the New Jersey shore standing at 25m above sea level and who therefore stands to gain a lot in home value *if* a 16m rise is realized)

  24. Oh! The magic of photoshop . . . . and the imagination of GIGO artists!

    “It is very difficult for the honorable (hu) man to compete with a “crook” . . . unless of course you want to become one . . . ”

    I heard that somewhere but I don’t remember who!

    Now, back to looking for a job . . . . that does not entail being the “fall guy” for some scam artist!!!

  25. Won’t the added weight of water depress the thin crust of the ocean floor, squeezing mantle material under the continents, thus forcing the continents to bob up, deform and break apart? Seriously, global warming might cause the entire world to crack up.

  26. The fact is that as CO2 levels have gone steadily up, and surface temperatures have trended unsteadily up, the rate of sea level rise has not gone up at all. That is the single most important fact for anyone to know about sea level rise.

    We’ve done the experiment: After a 1/3 increase in atmospheric CO2, with atmospheric levels rising steadily over 2/3 of a century, the rate of sea level rise has not increased at all. The so-called climate scientists who predict catastrophic rates of sea level rise are expressing ideology, not science. The evidence is overwhelming: anthropogenic CO2 emissions do not lead to measurable increases in rate of sea level rise, and the climate models which predict otherwise have been falsified.

    The median rate of sea level rise at the 159 GLOSS-LTT tide stations (average record length 85 years) is nearly identical to the geographically-weighted average rate: 1.1 mm/year (3.85 inches over the next 89 years). The higher numbers you see claimed by alarmists everywhere result from model-derived adjustments to the data. For instance, the widely used GIA adjustments from Peltier add 0.3 mm/year to account for a theorized sinking of the ocean floor. But even if the number is correct (which would be surprising, considering the lack of agreement between the model-predicted GIA numbers and GPS-derived measurements) that’s not actual sea level rise anywhere except the mid-ocean. It’s some sort of water balance accounting, not real sea level rise. By that sort of accounting, if there were zero global sea level rise, then a coastal tide station where there was neither uplift no subsidence going on would measure a 0.3 mm/year decline in sea level.

  27. Grand claims of doom without even rubbish maths to back them up..a sure sign of pure BS
    So its hardly surprising to find the facts don’t back them up.

    ‘He has developed a model in collaboration with researchers from England’ in other words CRU which tells you almost all you need to know .

    ‘Their model has been adjusted backwards to the actual measurements and was then used to predict the outlook for rising sea levels.’ Well that good I like to know that these were 150 years ago or even 100 , any got the data or are we talking rather less time so that the data is actual rather meaningless over over geographical time scales ?

  28. Probably already mentioned on WUWT but govt’s at all levels are planning for and counting on a rise in sea level, likely as a convenient excuse to grab more power. I heard on the radio a few days ago that there is a San Francisco bay area agency called ABAG i believe(unelected) that has deemed it has the power to regulate/deny any building construction within 100 yards of the bay because by its thinking this land will be under water by 2050 iirc.

  29. Is there any way we can speed up this global warming thing to get the sea level to rise faster? All those flooded buildings will make great “structure” for fish and the fishing should be great.

  30. Your article leaves out the important fact that, on average, the human race has grown taller over the last several hundred years.

    Now, that is clear evidence of evolutionary change in response to a survival threat challenge.

    “Gullible’s Travels” rides again.

  31. The whole CAGW and modelling Krew seem to have a revulsion towards the “adaptation” option. All their scenarios really aim for an ideal “scenario” where a completely passive response to weather/climate change is all that happens. But since 70,000 ya when the last/first cohort of modern humans clung to the east coast of southern Africa, to the migrations across the Bering Bridge, to the coastal hopscotch around the margins of all the continents, to the diking of the Netherlands, the entire history of homo sap has been non-stop adaptation.

    Stasis is unavailable.

  32. I have sent this email to Dr. Grinsted:

    Dear Dr Grinsted,

    I wonder if you have seen the discussion of your recent paper on

    http://wattsupwiththat.com/2011/10/18/the-500-year-fud-about-sea-levels/#more-49429 ?

    I would be very interested in your comments. In fact, I think it would be valuable if you were to make a response on the site.

    Best regards,
    Richard Barnes

    I think that, when an email address is provided, the best policy is to invite the person to take part in the debate.

    PS. What does FUD stand for?

  33. nutso fasst says (October 18, 2011 at 12:05 pm): “Seriously, global warming might cause the entire world to crack up.”

    I don’t know about the world, but CAGW scare stories crack me up all the time.

    So Anthony, was this the week’s “Friday Funny”, or do we get two this week?

  34. “FUD”: Fear, Uncertainty, and Doubt.
    A marketing strategy employed by IBM long ago, and likely by many other companies and organizations, when they realize that they are losing in a competitive situation and want to raise (often or usually unfounded, or false) concerns in the prospect or customer or “sucker’s” mind, usually about their competitor.

  35. Of course humans dumping solid matter into the seas to create new land will also increase the sea level as will all that sediment carried into the sea by rivers.
    But just what is sea level? It can’t be measured against land height as that is in a state of constant flux and satellite measurements can’t be that reliable as the basins that the sea sits in are also continuosly changing shape and volume.

  36. based on what happens with the emission of greenhouse gases and aerosols and the pollution of the atmosphere

    They should be embarassed that this unscientific twaddle comes out of an institute named after one of the greatest scientists who ever lived.

  37. “Stonyground says:
    October 18, 2011 at 11:03 am
    Zac makes a good point, if all the world’s glaciers and both ice caps did melt completely, it must be possible to calculate what the sea levels would be.”

    The figure normally given is about 70 meters sea level rise, but that is probably on the high side since a fair amount of water would stay in the currently ice-covered parts of Greenland and Antarctica as lakes and rivers. Note that this requires complete deglaciation of interior East Antarctica where the current annual mean temperature is below – 50 Celsius (- 60 Fahrenheit), .

  38. From Jolly farmer on October 18, 2011 at 1:31 pm:

    PS. What does FUD stand for?

    F***ed Up Deception

    Well actually, it might as well be that, but it”s really Fear, Uncertainty, and Doubt. For example:

    Experts say the Red Chicago Blagobama Virus can kill people (fear), experts are uncertain who and how many the virus will kill (uncertainty), yet Tea Party conservatives have stated that federally-funded research to investigate this emerging killer is not needed (doubt).

    Now that you are convinced that the Red Chicago Blagobama Virus is a real and imminent threat to humanity, please give generously using the “Donate” link on the right so that we may lobby on your behalf for federal funding to stop this dangerous killer before it slaughters you, your family, or someone else you know! Act NOW before it’s too late!

  39. The green curve on Grinsted’s graph (which, if I’m interpreting the caption correctly, is the “emissions stabilized in 10 yrs” scenario) shows sea level actually dropping after about 2300 AD.
    So stopping CO2 emissions will even reverse the sea level rise that’s been occurring “naturally” for millennia!
    Powerful stuff, that CO2.

  40. To check the “sea-level rise is accelerating” bit, I went to the Colorado Uni sea-level pages, and this caught my eye: “2011 Release 2 (2011-07-19) … the rate increased slightly from 3.1 to 3.2 mm/yr due to the improvements to the TOPEX SSB model and replacement of the classical IB correction with the improved DAC correction, as noted above” (http://sealevel.colorado.edu/content/release-notes).
    Given that by mid 2011 the sea-level rise had clearly slowed, this statement seemed curious.

    Now it just so happens that I have two earlier downloads of the Colorado sea-level data, from a bit over 6 months ago and about a year ago. Graphing the three together shows how the data has been adjusted:

    Why am I not surprised that earlier years’ data have been adjusted downwards and later years upwards?

  41. SteveE says:
    October 18, 2011 at 10:23 am
    Do you not think that the sea level rise is more of a worry for the likes of place that receive a tidal surge during a cyclone, 60cm might make a large difference to places like Burma and Bengal.

    As has been reported here before, tidal deltas actually rise with sea level – its an effect of the river flow and silting that forms the delta. The delta silting has more than accounted for the slow rate of sea level rise in Bangladesh – I think you will find that the land area has actually grown.

  42. Thanks to those who answered my FUD question. I did business at a French grande école, so no fear, total certainty, and no word doubt in the dictionary.

    In fact, the French students all had this attitude, making it very easy to beat them at the computerised business games. They put their faith in spreadsheets.

    Sound familiar..?

  43. In Nova Scotia, Canada, along the Northumberland Strait, sea level (apparent) was between 4 and 7 metres higher than present. This can be measured by examining the upper limit of raised beaches and wave cut platforms overlain by beaches. The difference of between 4 and 7 is because the wave cut platform is tilted and thus systematically varies in height along its exposure. This is due to differential isostatic uplift since the platform was cut by the ocean during the Sangamon Interglacial. One could argue that if all things were equal, one could expect a minimum of 4 metres of additional sea level rise if conditions matched those during the Sangamon. Simple? No!

    Move now 150 kilometres southwest to the Atlantic side of Nova Scotia. Now one observes that sea level has transgressed the land, at present, beyond the point where there are any paleo-beaches or other raised marine features. Oops……. so does that mean that on the southern coast of NS we should expect another 4 metres of sea level rise. Is it because the southern coast is isostatically lower now then it was during the Sangamon?

    I could go on but not. What is the conclusion ….. it is obvious. It is that geology is an non-exact science open to many different interpretations using the same data. It does not lend itself to `consensus’. Something as simple as sea-level rise in a province as small as Nova Scotia is complicated, and with a `large data set’ cannot be easily explained.
    YET …… climate science has reached a consensus and you can;’t even get a consensus in NS on sea-level rise? Sorry if I am skeptical.

    Now a question for the readers. I remember reading on (this site or another site) a discussion about using 2nd order, 3rd order, log or exponential functions on data to make predictions. The gist was that these functions naturally go crazy based on simply increasing time….thus they are worthless. Go crazy was not the proper term used …it sounded much better ….was much better and correct. Would someone point me in the right direction for that link?

    2nd question..I have a data set of tide records for Halifax, Nova Scotia well exceeding 34,000 daily averages…… with weeks of work completed fixing `stuff’ in the data set. It is a 110 year old data set and one of only a hand full of these tide gauge records that are this long and more or less continuous. However, additional data exists that takes the record back to about 1850. Its British Admiralty paper data that I plan to acquire with great effort and time (I get paid to do it but it isn’t `big oil money’.

    Based on an initial look at the date around 1900, and work by Gehrels, 2005(6), it will show a sudden increase in the rate of sea-level rise around 1910ish (doubling) … long before it could relate to CO2 forcing. This additional data does not exist in the peer reviewed scientific literature. I am looking for someone to assist me with a proper statistical analysis of the data set. Stats is not my specialty and no one else in my circle of peers is much better.

    If anyone is interested e-mail me at philipfinck@eastlink.ca. The result will be peer reviewed and published, probably in a few different locations and I’m more than willing to give proper recognition for the work …we can discuss it. I’m open to suggestions and discussion on additional ideas of where, how, form of where it might additionally be used.

  44. Bruce says:
    October 18, 2011 at 9:59 am

    “I must be missing something. The Hansen article that you quote and link in the above article says 40 years not 20 years! ”

    Typical revisionism. When it came to light, a lot of gnashing of teeth came about, even going as far as to drag out the reporter whose recollections tended to change, despite what he originally reported.

    It was covered on here a while back if you wish to got digging around for it.

  45. At least all these CAGW models are consistent in their broad details:

    1) if we do nothing, we face apocalypse;

    2) If we dismantle capitalism immediately, we will just dodge the climate bullet and be forever grateful to those wise AGW supporters who steered the bovine masses away from the brink of disaster.

  46. Re the photoshopped 78 metre sea level rise – all the ice in the world could melt and there would only be – well, estimates vary, but are usually in the 60s. I did a rough calculation by simply smearing all the ice out over the existing ocean area, ignoring the shrinkage as it converted into water, and got 76 metres, so that is the absolute hairiest scariest maximum.

  47. In 26,000 years the Earth should, by all measures, be halfway down the slope to the bottom of the Next Ice Age, with sea level down 100-200 feet.
    Think of the boom it will create with all that continental shelf newly exposed.

    Google that.

  48. Hum, they are predicting a transgressive sequence not unlike the sequences of the Cretaceous responsible for much of the hydrocarbons in Western North America. Of course everyone knows that transgressive sequences have regressive sequences along with them in a kind of back and forth movement. All very natural and normal just ask Albertasouris. Oh, can speak dinosaur. No problem, the models do that don’t they.

  49. The first land reclamation was undertaken by Peter Stuyvesant upon taking over as the colony’s governor in 1646. … Back then, this was still called New Amsterdam, and the Dutch were great believers in canals.

    I have a great-something grandmother who was born in New Amsterdam in 1634, so welcome to America, all you newcomers. Judging by the animation, in 500 years the Hudson river will be no
    more than another Dutch canal running through reclaimed landfill. Of course, in 500 or a 1000 years we may be sliding into the next ice age, assuming we aren’t already sliding from the peak in 1998.

    And assuming those NYC buildings are so well built that they last 26,000 years, that won’t be water in the image, it will be ice.

    The fig. 1 chart shows radar sea level data from Topex satellite running up to 2010, however Topex died in 2006, which is a good thing, because all that downwelling Topex microwave radiation was probably what was melting the Greenland glaciers.

  50. To the attention of Anthony Watts

    I’m glad adding a picture featuring France undersea to your collection. Boy tells :
    I Thomas, 8, future climate refugee.

    It was the poster of the 4th International Forum of Meteo in 2007,
    official site http://www.smf.asso.fr/fim07.html
    same poster in high and low definitions here (Affiche)
    http://www.smf.asso.fr/fim07_presse.html

    Note : sponsors of the poster includes
    National meteorological office,
    government agencies
    EU commission
    corporations, etc.

    Sincerely yours

    F. M.

  51. I think we should send this to Australia, Rolling Stone already has them dead in the water and or withered from GW. What a crock!

  52. zac says:
    October 18, 2011 at 2:29 pm
    “Of course humans dumping solid matter into the seas to create new land will also increase the sea level as will all that sediment carried into the sea by rivers.”

    Just the point I was making to my Grandson yesterday as he tried to skim pebbles into the sea. We must educate the young and stamp out this danger to civilization! Multiply all the young ones doing it and a huge amount of sea rise is being missed by the models, never mind the quality of the data produced by the tidal gauges! ;-)

  53. RE: zac: (October 18, 2011 at 2:29 pm)
    “Of course humans dumping solid matter into the seas to create new land will also increase the sea level as will all that sediment carried into the sea by rivers.”

    One might think that all that sediment running into the sea would eventually depress land levels as well as increase sea level, but wait a minute, isn’t there something called ‘plate tectonics’ that is continuously sweeping sediment off the ocean floor and building mountains? Perhaps one component of sea level rise or fall is net plate tectonic activity.

    By the way, some of the writers of these doomsday scenarios have cited the projections of Dr. Stefan Rahmstorf, who is a German Professor of Physics of the Oceans at Potsdam University who says he believes the hockey stick temperature rise, supposedly ‘unique’ to this century, may have already gone beyond the point of no return in setting the stage for a major arctic meltdown.

  54. I was working in the Philippines last year and got talking to a Middle School Science Teacher who asked me, as a western Engineer (not many ’round eyes’ around the area I was working in) to come into his class and talk about the power station project I was working on. I thought this a great idea and readily agreed. I arranged to meet the Teacher again to go over details, after securing some time off from the project, and we got talking about what he was teaching his children.
    The teacher mentioned AGW as a special topic, and as an educated westerner, would it be possible for me to instruct his class on the general points associated with this biggest danger to the world today. To his horror, I said that I would be happy to talk about AGW as the scam that it is. ‘But sea levels have risen 6m (six metres) in Pangansinan, Luzon, Philippines in my life-time!’ he exlaimed. I advised him that, however close to his pension he was, he was not over 20,000 years old. My looked-forward-to class meeting was abruptly cancelled.
    Long story short; even the unfortunately limited education these wonderful Philippine children receive is being highjacked by the AGW scam, with apparently educated Teachers believing that sea levels have risen massively in a short period of time. I thought it was only in the west that our children are being brainwashed.

  55. First of all, that famous graph showing the Meltwater Pulse clearly shows one thing, Seal level has been rising continuously since the Holocene began. All rising sea-level discussions are fraudulent already because sea-level is clearly supposed to be rising. If they’re only rising in the mm per year range, we may actually be in trouble because that graph shows that the last time sea-level did NOT rise was leading up to the last glacial maximum.

    Secondly, any sea-level rise would *first* have to overcome the manmade expansion in NYC into the water. Both the East river and the Hudson are narrower at NYC these days. Such expansion is going on all around the world. There will not be enough sea-level rise to even wash over the synthetic Battery Park City, and it will never get near the original island.

    Finally, I wish the alarmists would start making a parallel calculation when they project Greenland melting to account for all the water that would remain landbound in freshwater lakes. The melting of Greenland would create really really great lakes (pardon the pun). Greenland would become the world’s greatest exporter of bottled water for the hip crowd. Just picture little plastic bottles with a picture of a Viking on it, called ‘Glacier Water’! I would buy stock in this lickity split.

    P.S. Anthony, excellent job on that Animated GIF! There is another one floating around the internet showing pretty much the whole island and it’s growth but I cannot find it. I’ll be linking to yours instead!

  56. I have received the following from Dr Grinsted:

    Hi Richard

    I have not seen the wuwt page yet.

    Frankly, I am reluctant to go or even visit there because I know that whatever I say there will be attacked by an angry mob of commenters which are unable to listen to reason. There may be a few individual posters/commenters that are the exception to the rule.

    I have previously commented on climateaudit which atleast has a moderately polite tone (unlike wuwt), but still I did not find the experience constructive. I frankly do not think that anybodys positions were moved (I weren’t weren’t).

    Finally, I think that WUWT completely lacks any editorial filter beyond only allowing ghg skeptics to write. It allows all kinds of basement cranks to write even when it must be obvious to Watts that it is an incoherent ludicrous mess.

    To me, wuwt is just a noise horn with the only intent to delay any efforts to mitigate a serious problem.

    Pros of posting there:
    It feels good to set the record straight.
    I may move 0-2 persons slightly.

    Cons:
    I have work to do that I feel is much more constructive.
    I will be attacked by a lynch mob.
    I lend credibility to the site by taking them seriously.

    I will read the page at work, and perhaps I will make a single comment.

    -Aslak Grinsted

    I have sent this in response:

    Dear Dr Grinsted,

    Your reply has brought to mind the words “pot”, “kettle” and “black.” Consider for a moment the vocabulary you have used:

    “angry mob”
    “unable to listen to reason”
    “basement cranks”
    “incoherent ludicrous mess”
    “noise horn”
    “lynch mob”

    I agree that politeness is important in debate. Using this kind of language does not help at all.

    I will post your reply on the sea level thread. I urge you to add your comment. You will find that your remark “only allowing ghg skeptics to write” is without foundation.

    Best regards,
    Richard Barnes.

  57. This tomfoolery about sea level rise is perplexing, looking at the long term post ice age chart the sea levels have risen at about the same rate for 8 thousand years.

    The perplexing part is that it is a static 2 to 3 mm for eight thousand years. This tends to point to the fact that their is no extra water being added or only a minor quantity.

    The answer has to lay else where, the odd dust storm and sand storm, the huge quantities of debris and silt from the worlds rivers and floods from the yearly monsoons. These are minor as is the millions of micro meteorites that rain down.

    The billions of tons of little critters that live and die fed by the nutrients that find their way to the oceans by the erosion of the continents, they dieand fall to the bottom of the abyss, that is the briny deep, all add to the space occupied by the oceans.

    This natural process I am sure adds in some way to the surface rise of the oceans and may account for most of it as it seems a constant.

    My question to those with more knowledge would be how much is the average sea bottom sediment layer growing per year?

  58. John Hayzen-Smith – Minor correction: The sea level has risen about 120 metres in 21,000 years (IPCC report AR4 FAQ 5.1), so your Philippino friend would not need to be 20,000 years old to have witnessed a 6 metre rise. More like 2,000 years old (I think the rise rate was higher in the earlier years).

  59. Mike Jonas

    More like 8-10 000 years, the rise has been very slow since the last remnants of the Laurentide ice melted about 8 000 years ago. And it actually is possible that the sea-level in Pangasinan has risen perceptibly (though not 6 meters) in a lifetime. The Philippines is a very unstable place tectonically.

  60. Assuming Earth stays in the warm phase of the millennial climate cycle until at least 2100 (not a huge assumption), the maximum possible sea level rise by then will be a bit more than 0.25m above current MSL.

    1/4 of a meter… A bit less than 1 foot… That’s it… That’s the worst case scenario that is actually possible in the real world.  

    The climate modelers make me think of an Aubrey McClendon (CEO of Chesapeake Energy) quote:  

    “That kind of analysis, I think, can only come at the dangerous intersection of Excel and PowerPoint. It can’t happen in reality.”

    http://
    debunkhouse.wordpress.com/2010/04/17/oh-say-can-you-see-20th-century-sea-level-changes-when-viewed-in-a-geological-persp
    ective/

    http://debunkhouse.wordpress.com/2010/05/20/the-national-academy-of-sciences-forecasts-sea-level-rise-of-22-mmyr/

  61. REPLY: So might tides which can be as large or larger. Shall we then modify the orbit of the moon to prevent high tides? It is about as plausible as the claims on CO2 emissions equating to sea level – Anthony

    I think adjusting the moons orbit is a bit extreme even for you Anthony. It only follows that if sea levels were to rise by 60cm then the tidal surge would also rise by at least that much. The Nargis Cyclone had a storm surge of 12 feet so an extra 60cm on that would increase it to 14 feet. Would that not have seen even more wide spread devestration that killed an estimated 138,000. Who knows? I’m sure it wouldn’t have improved matters though.

  62. Would it not be possible to calculate (under, say, warmista assumptions) how long it would take to completely melt:
    1) the Greenland ice-cap
    2) the Antarctic ice-cap?
    I realize that you are a busy man, Mr Watts, and that there are only 24 hours in a day, but one of your denizens is surely capable. I’d do it myself, if my math/physics was up to it.

  63. A classic and thought through explanation of what is going on as regards sea level hysteria.
    A dissection job of inspired genius, please accept my thanks and best regards.

  64. @Skeptik says:

    October 19, 2011 at 6:37 am

    A recent publication by a team from TU Delft & JPL found that the Greenland ice sheet was melting at half the rate previously thought. They estimate that the Greenland ice sheet is losing ~230 gigatonnes (Gt) of ice per year. One Gt of water has a volume of 1 cubic km (km^3). 1 Gt of ice has a larger volume than 1 Gt of water… But, for the purpose of this exercise, we’ll assume 1 Gt of ice has a volume of 1 km^3.

    If 1 Gt of ice has a volume of 1 km^3 and the current volume of the Greenland ice sheet is ~5 million km^3 and Greenland continues to melt at a rate of 230 km^3/yr over the next 90 years… The Greenland ice sheet will lose a bit more than 0.4% of its ice volume.~230 gigatonnes (Gt) of ice per year equates to about 0.005% of ice mass loss per year. At the current rate, it would take 1,000 years for the Greenland Ice Sheet to lose 5% of its volume.

    The Earth’s climate was at least 1°C warmer during the Holocene Climatic Optimum and the Greenland Ice Sheet did not melt, disappear or destabilize.

    The Earth’s climate was at least 2°C warmer and the Arctic was about 5°C warmer than it currently is during the Sangamonian (Eemian) interglacial. and the Greenland Ice Sheet did not melt, disappear or destabilize.

    Greenland’s glaciation began during the Miocene, when the Earth’s climate was at least 5°C warmer than it currently is. It advanced rapidly after the Mid-Pliocene Warm Period.

    Earth’s climate would have to warm back up to where it was in the mid-Miocene (~15 MYA) in order to destabilize the Greenland ice sheet.

    There is no scientific evidence to back up the assertion of a “disappearing Grrenland Ice Sheet.  For a detailed explanation as to why the Greenland ice sheet cannot collapse under any AGW scenario, see Ollier & Pain, 2009.

    http://debunkhouse.wordpress.com/2011/01/22/more-glacial-junk-science-journalism/

  65. LBtT;
    The leap, of course, it that it was a period of “warming” that created the desert. Given that the recent warming has greened the eastern Sahara (the Sahel), said Great Leap is probably another one in exactly the wrong direction.

  66. The first image, above, of Manhattan underwater appears on the cover of Heidi Cullen’s book, “The Weather of the Future.” At the time I presented much of the same evidence to the contrary that is presented here.

    One of the amazing things to me is that “The Village” area, Chelsea, the Garment district and the rest between Lower Manhattan and Midtown Manhattan is shown completely underwater, without hundreds of buildings poking out. As you can see here…

    http://climatesanity.wordpress.com/2010/08/21/manhattan-underwater/

    that region is covered with buildings that are hundreds of feet tall.

    You might also be interested in my short series “Cities Underwater” with examines claims of inundation for Manhattan, Boston, Vancouver, and Los Angeles…

    http://climatesanity.wordpress.com/cities-underwater-2/

    Tom

  67. 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 . . . .

  68. 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.

  69. 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.

  70. 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.

  71. BrianH: If I misinterpreted the intent of your statement, I hope you will understand . . . . I suppose that is what dialog is for . .

  72. 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?

    • Durn good guestions daveburton . . . . I wouldn’t mind the answers to those myself . . .

  73. Laurie Bowen says:
    October 20, 2011 at 8:30 am

    BrianH: If I misinterpreted the intent of your statement, I hope you will understand . . . . I suppose that is what dialog is for . .

    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 . . . .”

  74. 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?.

  75. 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

  76. 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.

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