New predictions for sea level rise
Sea level graph from the University of Colorado is shown below:
University of Bristol Press release issued 26 July 2009
Fossil coral data and temperature records derived from ice-core measurements have been used to place better constraints on future sea level rise, and to test sea level projections.
The results are published today in Nature Geoscience and predict that the amount of sea level rise by the end of this century will be between 7- 82 cm (0.22 to 2.69 feet)
– depending on the amount of warming that occurs – a figure similar to that projected by the IPCC report of 2007.
Placing limits on the amount of sea level rise over the next century is one of the most pressing challenges for climate scientists. The uncertainties around different methods to achieve accurate predictions are highly contentious because the response of the Greenland and Antarctic ice sheets to warming is not well understood.
Dr Mark Siddall from the Earth Sciences Department at the University of Bristol, together with colleagues from Switzerland and the US, used fossil coral data and temperature records derived from ice-core measurements to reconstruct sea level fluctuations in response to changing climate for the past 22,000 years, a period that covers the transition from glacial maximum to the warm Holocene interglacial period.
By considering how sea level has responded to temperature since the end of the last glacial period, Siddall and colleagues predict that the amount of sea level rise by the end of this century will be similar to that projected by the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).
Dr Siddall said: “Given that the two approaches are entirely independent of each other, this result strengthens the confidence with which one may interpret the IPCC results. It is of vital importance that this semi-empirical result, based on a wealth of data from fossil corals, converges so closely with the IPCC estimates.
“Furthermore, as the time constant of the sea level response is 2,900 years, our model indicates that the impact of twentieth-century warming on sea level will continue for many centuries into the future. It will therefore constitute an important component of climate change in the future.”
The IPCC used sophisticated climate models to carry out their analysis, whereas Siddall and colleagues used a simple, conceptual model which is trained to match the sea level changes that have occurred since the end of the last ice age.
The new model explains much of the variability observed over the past 22,000 years and, in response to the minimum (1.1 oC) and maximum (6.4 oC) warming projected for AD 2100 by the IPCC model, this new model predicts, respectively, 7 and 82 cm of sea-level rise by the end of this century. The IPCC model predicted a slightly narrower range of sea level rise – between 18 and 76 cm.
The researchers emphasise that because we will be at least 200 years into a perturbed climate state by the end of this century, the lessons of long-term change in the past may be key to understanding future change.
Please contact Cherry Lewis for further information.
Further information:
The paper: Constraints on future sea-level rise from past sea-level reconstructions. Mark Siddall, Thomas F. Stocker and Peter U. Clark. Nature Geoscience .
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“The researchers emphasise that because we will be at least 200 years into a perturbed climate state by the end of this century”
So let me get this straight … they consider recover from the Little Ice Age a “perturbation”?
“Between 7- 82 cm” is little more than a child’s guess.
None of the bastard prophets is alive in the year 2100.
Sounds like a real catastrope… Oh, the humanity! Why, at this rate, half of Florida will be underwater by the time we’re fixing all the computers for the Y10k bug!
“. . . predict that the amount of sea level rise by the end of this century will be between 7- 82 cm – depending on the amount of warming that occurs . . .”
That’s what we like—precision! Though I was hoping for something closer to just one order of magnitude variance from the low estimate to the high.
I’m glad too that they reminded us that it all depends on the amount of warming that occurs. Thank you Captain Obvious.
“Furthermore, as the time constant of the sea level response is 2,900 years, our model indicates that the impact of twentieth-century warming on sea level will continue for many centuries into the future. It will therefore constitute an important component of climate change in the future.”
That’s what I call really tootin’ the horn over unproven predictions.
And how valueable is that model once a major cooling event hits?
About as valuable as “It’s never been a better time to buy a home” and Mortgage Backed Securities a sure thing.
I predict that sea-levels will be lower in 2100 because a 60 year cooling warming cycle gives this century two cools and a warm.
Uh huh so sea levels fluctuate.
I run regularly through “hills” on the sandy, clayey coastal plain of Virginia where there are no hills.
Yet running through this forest at points you forget you are near the Atlantic and the Gulf Stream because hardwoods like beech and maple and then seasonal wild blueberries predominate. Then you cross a “hill” and the tupelos, bald cypress and spanish moss are staring you in the face.
Reality sets in as you are running along near one of the boundaries of the worlds’ great oceans and the hills thereto are not tectonic or volcanic.
They are sand dunes [now forested] which formed at an ancient ocean boundary during the Holocene Climatic Optimum…
Climate changes….that’s what it does.
And so does sea level….
No f-ing big deal….
SEA LEVEL CHANGE HAPPENS.
If we are smart we will learn to adjust to the natural cycles.
Chris
Norfolk, VA
It must be an authoritative study, as they used the range of warming predicted by IPCC 4 to calculate the possible sea level rises. Its a pity they didn’t do some detective work instead, & investigate if the data & methods used by the modellers whose papers were looked at, (not reviewed in the scientific sense), to produce IPCC 4, has any basis in reality.
It is of vital importance that this semi-empirical result
Semi-empirical is Climate_Science_Speak for, we took some real data, ran it through a model of unknown validity and produced these results.
Had they used telephone numbers instead, which are real data, the result would have been semi-empirical.
Models, and more models? Why don’t scientists use real time data readily available?
The analysis of 53 sea level stations, distributed all over the world,
suggests a decline of sea level by almost two feet, by 2100, if it
continues the downward trend observed over the last three years. Even
considering the average value for the last 9 years, this would lead to
a rise of only one inch during the XXI century.
The data used was obtained from the University of Hawaii, which has
the most updated data available on the Internet. Why is the official
data from the IPCC, and others, so different? Simply because it does
not take into account updated and recent data. According to the
Wikipedia page about sea level rise, the most recent data used in
international studies is related to 2003! The data used in this study
is updated up to May this year.
The original data and report is available through
http://ecotretas.blogspot.com/2009/07/sea-level-decline.html
Ecotretas
7 to 82 cm?
They do like to hedge their bets, don’t they?
Or how about: “Our models show conclusively that bees can’t fly.”
Ecotretas (23:13:47) :
I went to check the sea-level report, clicked through to here:
http://www.slideshare.net/Ecotretas/sealevel-1792065
But the website doesn’t load up so well, maybe due to my PC, but just to let you know the website might need some work…
Interested in the report though – I do wonder about these sea level figures, I expect they are open to manipulation or at least +ve bias by the warmers.
Not to mention that even if they hit the median we’re looking at 1 foot in 100 years which is to the low side of natural variability, ie. of practically 0 consequence.
Dr. Siddall and colleagues studied the precedent fluctuations of the sea level using the proper methodology. The problem is that their projections are based on speculations, i.e. the projections made by the IPCC based on a spurious climate sensitivity constrained by carbon dioxide.
I agree on the probabilities of increasing temperatures in the next centuries; however, I don’t attribute those changes to carbon dioxide produced by human activities, but to nature.
As I have said it many times here, the Earth is leaving off a regression phase caused by a prolonged icehouse. The natural fluctuations of temperature given in the past 12000 years have been of around 6 °C to 10 °C, so it would be quite normal a change of 6 °C to 10 °C.
Regarding the rising of the seal level, it has occurred many times in the geological records. The “movements” of the sea level usually occur in long alternate periods consisting of four phases:
1. Transgression phase, which consists of larger flooded continental areas.
2. Highstand phase, which is the maximum (highest) sea level.
3. Regression phase, the sea level retreats and the percentage of continental flooded diminishes.
4. Lowstand phase, which is the minimum (lowest) sea level.
The Earth has left the lowstand phase and perhaps is abandoning the regression phase for reentering to a transgression phase classical of a warmhouse period which has nothing to do with human activities.
Perhaps human activities could put us under genuine perils by socioeconomic reasons, not by environmental disasters. Nonetheless, the fluctuations are perfectly ordinary on this planet.
Unfortunately, not all the people are biologists. Heh! (It’s a joke) 😉
7 to 82 centimetres and that is termed ‘nailed?’ I would not wish to live in a wooden house built by a carpenter who holds the same idea of ‘nailing’!
REPLY: It is sarcasm you know
“Between 7- 82 cm”
Well at least they are honest that they have no idea. They may as well say our models show the rate of sea level rise depends on the rate of sea level rise.
Some background.
The 20th century sea levels rises are generally accepted (by climate science) to be be approx 2/3rds thermal expansion of the oceans, 1/3 glacial melt.
The problem is we don’t have any worthwhile measurements to back this up. It’s little more than speculation.
Someone here pointed out that you could account for 2/3rds of the sea level rise to aquifer water extraction and the rest to seepage from relic ice age bogs.
For those of those of you who haven’t been to the permafrost. It is one vast bog, beneath which there is a column of frozen water of varying depth. I have never seen an estimate of the amount of water stored in the permafrost, but I am sure it is a very large number.
NS,
As I can’t upload PDFs in blogger, I had to use slideshare. It works OK with me. I can send the PDF to whoever is interested. Please send me an email (look for the gmail email on the top left side of my blog), and I will send it back.
Ecotretas
So in short:
“Sea level rise will either slow, remain the same, or increase.”
That just about covers every possibility. I believe their conclusion has a chance of being 100% accurate.
They predict that the amount of sea level rise by the end of this century will be between 7- 82 cm – depending on the amount of warming that occurs.
Does that mean if there is cooling that the level will fall by between 7-82 cm?
Is another way to express it 37.5 cm plus or minus 30.5cm or therabouts?
between 7 – 82 cm
Close enough for government work — if by “work” you mean trillion dollar Tax-and-Stifle economy-busting boondoggle programs designed by Enron-wannabe Euro-trash worshipping Nobel lariat demagoguing $cientists from the Alarmosphere …
“The new model explains much of the variability observed over the past 22,000 years and, in response to the minimum (1.1 oC) and maximum (6.4 oC) warming projected for AD 2100 by the IPCC model”
1.1oC relative to when and what baseline?
I think they should give their models to the Met office, if they just change cm for F, the met office could say that this winter will average somewhere between 7F and 82F. That would be there most accurate forecast to date.
Richard Heg said: “Between 7- 82 cm” Well at least they are honest that they have no idea. They may as well say our models show the rate of sea level rise depends on the rate of sea level rise.
yep. That’s about right!