From the Guardian, finally some refreshing honesty in Science:
Climate scientists withdraw journal claims of rising sea levels
Study claimed in 2009 that sea levels would rise by up to 82cm by the end of century – but the report’s author now says true estimate is still unknown
The Maldives – poster child for bad science Photograph: Reuters
Scientists have been forced to withdraw a study on projected sea level rise due to global warming after finding mistakes that undermined the findings.
The study, published in 2009 in Nature Geoscience, one of the top journals in its field, confirmed the conclusions of the 2007 report from the Intergovernmental Panel on Climate Change (IPCC). It used data over the last 22,000 years to predict that sea level would rise by between 7cm and 82cm by the end of the century.
At the time, Mark Siddall, from the Earth Sciences Department at the University of Bristol, said the study “strengthens the confidence with which one may interpret the IPCC results“. The IPCC said that sea level would probably rise by 18cm-59cm by 2100, though stressed this was based on incomplete information about ice sheet melting and that the true rise could be higher.
Many scientists criticised the IPCC approach as too conservative, and several papers since have suggested that sea level could rise more. Martin Vermeer of the Helsinki University of Technology, Finland and Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany published a study in December that projected a rise of 0.75m to 1.9m by 2100.
Siddall said that he did not know whether the retracted paper’s estimate of sea level rise was an overestimate or an underestimate.
Announcing the formal retraction of the paper from the journal, Siddall said: “It’s one of those things that happens. People make mistakes and mistakes happen in science.” He said there were two separate technical mistakes in the paper, which were pointed out by other scientists after it was published. A formal retraction was required, rather than a correction, because the errors undermined the study’s conclusion.
…
In a statement the authors of the paper said: “Since publication of our paper we have become aware of two mistakes which impact the detailed estimation of future sea level rise. This means that we can no longer draw firm conclusions regarding 21st century sea level rise from this study without further work.
h/t Claude Harvey
@ur momisugly kwik:
“Yes, its a victory. They were afraid of SealevelGate.
Hehe.
But it will come anyway;”
And your conviction regarding this is founded on some interview published in a journal of the LaRouche-sect. Good luck with that.
rc
@Shane O.:
“This from the side that seems to assume that all (any?) skeptics are ‘in the pay of big oil’?”
Why does it seem to you that I assume and what I assume? Have I made any statement that implies this? Or are you just making an assumption yourself about my assumptions?
At the end, the evidence counts, also with respect to any statement about who is paid by whom, doesn’t it?
rc
@kwik:
“Oh really? So you believe the output from their expensive Playstation? Next time when it spew out another number, will you believe it more? Why?”
Of course, this is just a caricature of what is actually done to ridicule results from scientific research that contradicts your own ideological bias and, therefore, isn’t liked. You apparently prefer to believe dubious, non-scientific sources like what is produced by LaRouche, because those are certainly much more trustworthy. It’s your choice.
rc
Firstly – very many thanks to Anthony and all the contributors to WUWT. I am not a scientist, my formal education stopped at school senior level Maths, Physics and Chemistry therefore a lot of the technical arguments are beyond my learning. I have however travelled extensively and being an offshore sailor and traveller I have experienced a great number of nature’s excesses up front and personal. These range from volcanic eruptions, earthquakes, artic cold, desert heat, water spouts and Atlantic storms. The power of nature has always fascinated me, but I have also seen its more gentle side in the calm after the storm, flowers growing on volcanic rims and a desert scene sprouting in bloom after spring rains. Also as a sailor I make use of sea current, wind and solar energy to run my offshore sailing boat.
These experiences led me to doubt that man was or is ever powerful enough to greatly influence earth’s natural elements. In the early days I felt that I stood out rather against the tide, being insulted, mocked and general dismissed as some sort of crank with a hidden agenda. The excessive and alarmist predictions using doctored photographs and mass political in-doctrine just reinforced my opinion. Thanks to sites such as WUWT the groundswell of opinion has slowly changed and we are seeing knowledgeable challenges to the data on which the predictions are based.
I am passionate about looking after our habitat and our natural resources but recognise that our efforts in that direction are small compared with natures capability to adjust and manage itself.
In the UK it is taking some time for our mainline institutions(Government, BBC, Met Office and many science journals/newspapers) to get off Climate Change bandwagon. Once they do we will be able to get sensible discussion and debate around this subject. That time cannot come soon enough.
Grateful to you all.
I believe some are in danger of overplaying their satisfaction at this retraction – as some have already mentioned.
In their original paper, Siddall, Stocker & Clark had stated :
“In response to the minimum (1.1C) and maximum (6.4C) warming projected for AD2100 by the IPCC models, our model predicts 7 and 82cm of sea-level rise by the end of the twenty-first century, respectively.”
http://www.nature.com/ngeo/journal/v2/n8/abs/ngeo587.html
Vermeer & Rahmstorf, however, stated in their contemporaneous paper :
“For future global temperature scenarios of the Intergovernmental Panel on Climate Change’s Fourth Assessment Report, the relationship projects a sea-level rise ranging from 75 to 190 cm for the period 1990–2100.”
http://www.pnas.org/content/early/2009/12/04/0907765106.full.pdf
That means that they are predicting a FAR LARGER rise.
Now, Siddall admits they were wrong and states :
“We thank S. Rahmstorf and M. Vermeer for bringing these issues to our attention.”
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo780.html
Siddall et al’s (lower) projection withdrawn; Rahmstorf & Vermeer’s (higher) not.
What does that tell you : That the lower estimate was too low ? Most likely.
jc,
We see you are a young, impressionable person caught up in what is supposedly known and having no clue about what is unknown and the uncertainty in what is known. You will learn one day. You will feel foolish and you will learn from this mistake. Good luck.
Oops, that should be addressed to rc.
Steve Goddard wrote :
“Sea level is rising at no more than 32cm/century.
http://sealevel.colorado.edu/current/sl_noib_global_sm.jpg
not 2,500cm as has been attributed to Hansen.
http://www.physics.utoronto.ca/news_repository/will-oceans-surge-59-centimetres-this-century-or-25-metres”
Come on – that is very laboured.
The Hansen et al. paper from 2007 referred to one by Dowsett et al. which states :
“These data indicate middle Pliocene sea level was at least 25 m higher than present, presumably due in large part to a reduction in the size of the East Antarctic Ice Sheet. Sea surface temperatures were essentially equivalent to modern temperatures in tropical regions but were significantly warmer at higher latitudes. Due to increased heat flux to high latitudes, both the Arctic and Antarctic appear to have been seasonally ice free during the middle Pliocene with greatly reduced sea ice extent relative to today during winter.”
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VF0-488G8SP-2&_user=10&_coverDate=12%2F31%2F1994&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=e2fb263a1aa7f9459d4956f147c56f95
Hansen et al. say, among other things :
“It is possible, but uncertain, that such a sea-level rise would occur with additional warming less than 1°C today. But what is clear is that global warming to the level of the middle Pliocene, when sea level was 25±10 m higher, would be exceedingly dangerous.
That history reveals large changes of sea level on century and shorter time-scales. All, or at least most, of glacial-to-interglacial sea-level rise is completed during the ca 6 kyr quarter cycle of increasing insolation forcing as additional portions of the ice sheet experience albedo flip. There is no evidence in the accurately dated terminations (I and II) of multi-millennia lag in ice sheet response. We infer that it would be not only dangerous, but also foolhardy to follow a BAU path for future GHG emissions.
The imminent peril is initiation of dynamical and thermodynamical processes on the West Antarctic and Greenland ice sheets that produce a situation out of humanity’s control, such that devastating sea-level rise will inevitably occur. Climate forcing of this century under BAU would dwarf natural forcings of the past million years, indeed it would probably exceed climate forcing of the middle Pliocene, when the planet was not more than 2–3°C warmer and sea level 25±10 m higher (Dowsett et al. 1994). The climate sensitivities we have inferred from palaeoclimate data ensure that a BAU GHG emission scenario would produce global warming of several degrees Celsius this century, with amplification at high latitudes.”
http://rsta.royalsocietypublishing.org/content/365/1856/1925.full
By the way, I recommend everyone go to that Royal Society website and take advantage of their free access to all papers, to celebrate their 350th birthday.
Start here :
http://rsta.royalsocietypublishing.org/content/by/year
An interesting paper on sea level trends is “Recent global sea level acceleration started over 200 years ago?” GRL 2008 by Jevrejeva, Moore,Grinsted, and Woodworth. Non-paywall access at http://www.pol.ac.uk/psmsl/author_archive/jevrejeva_etal_1700/2008GL033611.pdf
It shows how the acceleration in sea level trends started at the end of the 18th century. Figure 3 shows sea level trend since 1700 as an oscillatory curve of period around 60 years, with an underlying acceleration.
A relatively easy read. 4 pages. I highly recommend it to get a general feel for the natural variation and increase in sea level rate-of-rise over the last 300 years.
CharlieA wrote :
“An interesting paper on sea level trends is “Recent global sea level acceleration started over 200 years ago?” GRL 2008 by Jevrejeva, Moore,Grinsted, and Woodworth. Non-paywall access at http://www.pol.ac.uk/psmsl/author_archive/jevrejeva_etal_1700/2008GL033611.pdf”
Yes. Another one which reckons the IPCC projections are too low.
JMurphy (15:38:19) : “Yes. Another one which reckons the IPCC projections are too low.”
And it supports the hypothesis that CO2 induced global warming was in full swing 200 years ago. Or ………. it also supports the hypothesis that much of what we are seeing today is natural variation.
Your pick as to which interpretation makes the most sense.
Henry @ur momisugly Charlie and JMurphy
Interesting paper but something is still not clear to me. Do we have any measurements on salinity, and how has salinity increased over the past 100 years? You see what I am getting at: what are the main drivers that cause the rise in the level? I suspect it is not just melting ice.
@Henry Pool — google “steric expansion sea level rise”
The estimates on the rise caused by the expansion of water as it warms is around 1/2mm/yr by most calculations, perhaps 1mm/yr by other.
One would expect that melting ice would make up the rest, but the estimates for that are much smaller than the remainder of sea level rise actually observed.
I haven’t seen salinity changes being postulated as a significant portion of the sea level rise.
Perhaps somebody else can point to a good a paper with between the estimated values for the sea level rise due to each of several components and a reconciliation between the sum of these component estimates the actual observed sea level rise, but I think there is still a big discrepancy.
As with many climate related items, it is clear that we have a lot more to learn.
Charlie A wrote :
“And it supports the hypothesis that CO2 induced global warming was in full swing 200 years ago. Or ………. it also supports the hypothesis that much of what we are seeing today is natural variation. ”
Well, since sea levels have been rising since the last glacial maximum about 20,000 years ago, what needs to be ascertained is how much extra that level is down to us. And since industrialisation has been ongoing since the mid to late 17th Century, perhaps there is no surprise about the increasing rise since 1700.
As the paper states : “…sea level acceleration up to the present has been about 0.01 mm/yr2 and appears to have started at the end of the 18th century. Sea level rose by 6 cm during the 19th century and 19 cm in the 20th century.” I.E. The rate has been increasing each century since the late 1700s. It certainly wasn’t in ‘full swing’ until later periods.
The paper also states that if “the conditions that established the acceleration continue, then sea level will rise 34 cm over the 21st century.” I.E. It is still increasing. Why ? The paper suggests “the conditions that produce the present day evolution of sea level will continue into the future–though the acceleration will depend on the actual rate of temperature increase in the 21st Century.”
What is causing that ‘temperature increase’ ? What ‘natural variation’ do you have in mind ?
Henry Pool wrote :
“Do we have any measurements on salinity, and how has salinity increased over the past 100 years? You see what I am getting at: what are the main drivers that cause the rise in the level? I suspect it is not just melting ice.”
WIKIPEDIA is often a good place to start, because there are plenty of references to follow, which will lead elsewhere :
http://en.wikipedia.org/wiki/Sea_level_rise
http://en.wikipedia.org/wiki/Sea_level#Changes_through_geologic_time
http://en.wikipedia.org/wiki/Seawater
It would appear that salinity has been pretty stable for billions of years. It is the pH level that is changing : the seas becoming less alkaline.
I threw out a geologic perspective at the beginning of this thread. Another perspective might be this: If one takes numbers from the UN, spurious as they may be, regarding the volume of water used in crop irrigation, and apply that number to sea volume, one can account for 2/3rds of sea level rise, ~2.2mm/yr. It would be easy to see where lawns and flower gardens can account for the rest.
JMurphy (02:49:10) :Well, since sea levels have been rising since the last glacial maximum about 20,000 years ago, what needs to be ascertained is how much extra that level is down to us. And since industrialisation has been ongoing since the mid to late 17th Century, perhaps there is no surprise about the increasing rise since 1700.
As I pointed out at (2/21-19:42:37), the rate of increase for the past 12,000 years has been 83cm/century which is 8.3mm/year. So how is 3.3mm/year an increase?
Steve Keohane wrote :
“As I pointed out at (2/21-19:42:37), the rate of increase for the past 12,000 years has been 83cm/century which is 8.3mm/year. So how is 3.3mm/year an increase?”
Sorry, missed that. Could you provide your source for that, please ?
Some thoughts ..
The reason for most that has gone scientifically wrong in climate science the last 20 years is that it in part has come under the control of radical environmentalists, UNEP/IPCC etc.. and the UNFCCC political established doctrine on human made global warming and that it is a problem in the future.
Due to this situation we are getting more and more hockey sticks on past climate and todays climate.(HAdley CRU and Mann).
I just stumbeled over this:
http://ioc-unesco.org/
”
The importance of the oceans to global climate change cannot be underestimated. The GOOS contributes directly to the UN Framework for Climate Change Convention as the ocean component of the Global Climate Observation System. IOC science programmes support many studies of the impacts of climate change, including the International Ocean Carbon Coordination Project (IOCCP). The surface ocean currently absorbs almost one-third of the CO2 that is emitted to the atmosphere from human activities, including fossil fuel combustion, deforestation and cement production. The IOCCP coordinates continuous monitoring and research of the effects of increasing CO2 levels on the future acidity of the oceans, the effects on calcifying organisms and coral growth rates, and the changing climate effects on atmosphere/ocean exchange of CO2. ”
Just a tought:
What if the radical environmentalists UNEP/IPCC have the same control over IOC as they had over the Hadley CRU/Mann team?
Since global warming seems to be going nowhere. They really need somthing new and different in order to scare and distract away from ClimateGate etc..?
And that the field is open up for “projected” Hocey Stick’s that can scare so much that “Action Now”(radical change of society) is back on the front pages?