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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This deserves close study.
http://www.ocean-sci.net/5/193/2009/os-5-193-2009.pdf
A new assessment of the error budget of global mean sea level rate
estimated by satellite altimetry over 1993–2008
M. Ablain1, A. Cazenave2, G. Valladeau1, and S. Guinehut1
Sorry, we don’t get any Ancient Roman visitors here. The web server can’t handle Ancient Rome’s IP address of VII.LX.IX.. And their runners are all hanging around Olisipo, messages moldering while waiting for a long ship.
There will be at least 1 but fewer than 95 named Atlantic storms this year. Fewer than 96 of these will be a severe Cat 3 or greater…
Where’s my grant money…?
7 – 82cm is a range.
Key question:
What’s the difference in flooding betwen 7cm and 82cm?
If none, say so, because it won’t matter a stuff.
If a lot, show where gets flooded for 25cm, 50cm and 75cm.
Then it means something.
Although I do wonder whether I agree with the prediction…….
Between 700 and 7000. Thanks for the correction, charles. My brain is not the place to be at 2am…
Isn’t the IPCC’s range 0.18 to 0.59 m?
Jimmy Haigh (05:30:44) :
What if it gets colder?
I don’t think so because the progression is about alternate phases and the last icehouse, i.e. the present cooling period prolonged a bit beyond the typical span. Perhaps the Earth will have small periods (waves) of cooling into a longer warmhouse period.
Anyway, answering your question, if it gets colder, the sea level would undergo the regression phase… again, which is quite improbable. The natural trend is towards a transgression phase, again. It has nothing to do with anthropogenic activities. So nature behaves from more than 4000 million years ago.
Nasif Nahle (08:00:01) :
Here’s a field photograph I took when I was doing geological mapping in Trinidad showing Pliocene age (approx. 3.5MY) shallow marine sandstones (to the left) overlain by deep marine mudstones (to the right). The sandstones were deposited in about 5m of water and the mudstones about – say 50m. This was a very rapid transgression. The overall sequence (about 2km thick) was regressional.
http://i919.photobucket.com/albums/ad34/Jimmy1960/8TopofPtaPaloma.jpg
Alan the Brit (04:49:55) :
(I also heard that aerodynamically it is impossible for bees to fly).
Fortunately aerodynamics has advanced a little since 1934!
Can someone find out how much government money the group received for this study any 12 year in a science class could have figured out in a weekend?
What a waste
Underra
I wonder if it was Pevensey that you are thinking about- one of the ‘forts of the Saxon shore’-built in the 3rd century to keep out the Saxon invaders. The castle -still visible-now lies a mile or two inland but was very important at the time of the Romans. It is in Sussex, the next county along to Kent (sorry, I dont know if you are British and are aware of our geography or not,)
http://www.absoluteastronomy.com/topics/Anderitum
It was also where Wiliam the Conqueror landed and it is believed that the bay where he stepped ashore (now a mile inland) had recently been found. The Roman castle evolved into a Saxon fort and then a medieval castle. When it was built it commanded the entrance to a harbour and was surrounded by the sea on three sides.
It is one of several castle sites in Britain that show the subsequent retreat of the sea since Roman and Medieval times (separate to deposition or stasis) leaving castles high and dry. Harlech Castle in Wales is another good example. I posted information on Harlech here some months ago-if you are interested in this subject matter I will dig it out.
TonyB
Wouldn’ t it be, instead, from 6.9999 cm. to 81.9999cm., or from 7 meters to 82 meters….and why not from 7 nanometers to 82 nanometers?
It’s all the same: pure speculation. Once more: “Hollywood science”.
That doesn’t say much for their certainty of how much warming will occur, now does it?
None of the models and predictions take into account increased water usage (irrigation, creation of manmade rivers and lakes, etc) and absorption of sea level rise into coastal water tables. Taking these two into account I would say sea level rise for the foreseeable future is negligible.
Jimmy Haigh (08:26:48) :
Nasif Nahle (08:00:01) :
Here’s a field photograph I took when I was doing geological mapping in Trinidad showing Pliocene age (approx. 3.5MY) shallow marine sandstones (to the left) overlain by deep marine mudstones (to the right). The sandstones were deposited in about 5m of water and the mudstones about – say 50m. This was a very rapid transgression. The overall sequence (about 2km thick) was regressional.
http://i919.photobucket.com/albums/ad34/Jimmy1960/8TopofPtaPaloma.jpg
Indeed, the transgression sequence had its highstand some 3.42 mya, so the transgression phase, some 3.5 mya, happened exactly as you say, into a regression phase. The picture clearly shows the impetuosity of the transgressional event… quite interesting and informative. I have seen a similar kind of mud depositions somewhere in the eastern slope of the Anahuac Plateau, in Veracruz, but I didn’t give it too much importance because I was working into a different research (I was getting some facilities for indigenous people working in local mines). I’m planning to travel again to those places for obtaining more data, although I think the age could be different, perhaps older than 3.5 mya.
Urederra (03:43:15) :
Sorry for my mispelling of your name
tonyb
So, they have looked at 22,000 years of sea levels, and projected those findings forward and found that the rate of sea level changes agrees with the IPCC models. Let’s run the logic in reverse: the amount of sea level rise that is projected by the IPCC as a result of AGW is no different to that which occurred in the past. In otherwords, the projected warming is UNEXCEPTIONAL.
Case closed!
Phil. (08:43:20) :
Alan the Brit (04:49:55) :
(I also heard that aerodynamically it is impossible for bees to fly).
Fortunately aerodynamics has advanced a little since 1934!
Thankfully, otherwise the poor little things will start to fall out of the sky! I always have a problem with a theoretical law that says something should not do what it actually does, & clealry very efficiently too!
TonyB;-)
Well said sir!
Haven’t we been in a cooling trend for 10,000 years with the interglacial maximum reached 8,000 years ago? I read somewhere on this site that even with global cooling the ice will continue to melt and the sea will continue to rise until some level of cold is reached. I think the analogy used was that if you take ice out of the freezer and put it back in the refrigerator, it will continue to melt.
Curiousgeorge (04:01:43) : PS: Also, since most Americans don’t know the difference between a centimeter and carrot, here’s the translation: 2.75″ to 32.28″ .
This makes me remember that it is a silly thing for americans to change from their system of measures to SIM which has foolish measures as a circle of 400 degrees instead of one of 360 degrees. 360 comes from nature’s cycles while the 400 degrees figure comes from a fevered french revolutionary (Mssr.Tayllerand), with quite other objectives than those of a measuring system.
Don E wrote: “I read somewhere on this site that even with global cooling the ice will continue to melt and the sea will continue to rise until some level of cold is reached. I think the analogy used was that if you take ice out of the freezer and put it back in the refrigerator, it will continue to melt.”
I’ve never heard that, and would be suprised if it were true. It takes energy to melt ice, so imo if the temperature was below freezing the ice would not melt. It may have something to do with the notorious “heating still in the pipeline,” whereby cooling and warming can occur simultaneously. This is a very complex area of climate change, analogous to quantum mechanincs were a particle can exist in two places at once. Maybe it should be called the duality or simultaneity of climate forcings. Sorry, I’m meandering here.
well, let’s see, the Tide in Florida is about 3 feet. That would be….. ah, er, ahem…… 90 cm.
Anthony,
With all due respect, I really think you should publish the latest publication from Dr. David Evans, icecap.us and publish the Argo Graph that shows the sinking ocean temperatures on the right side of WUWT blog under the Arctic temp. graph, if possible.
As Dr. Evans explained in his article, ocean heat content is the latest “Bluff in climate alarmism and we should tackle it.
If I’ve done the calculations correctly, the rate of sea level rise would have to increase by 60% per decade from now until 2100 to get close to 82mm. That means sea level rise would increase from 3.2mm +/-0.4mm per year currently to 12mm +/-.5mm per year in the last decade of the century. That’s assuming the rate of increase is linear. If not, then it would have to be even higher.
That works out to about 1/2 inch of sea level rise per year by 2090!
Hmm.
Just looking at the chart we see that we have a rate ( since 1994) of 3.2mm
per year plus or minus .4mm. First we all need to recall that all measurement comes with error and if you propagate that error over time you get a spread.
Propagate that .4mm error over 100 years and you get +- 4cm.
If I have to make a guess ( put a gun to my head and make me guess) the first guess I will make is a naive guess. For sake of argument, you’ve got 3.2mm per year +- .4mm that gives you a 28cm-36cm rise over the next 100 years. That’s an 8cm spread. basically, you can’t get a more narrow range through modeling. On the assumption that a rise in C02 will result in a rise in temperature, and on the assumption that a rise in temperature will result in a rise in sea level, your error band can only increase. Why? because the models of C02 increase ( the SRES) assume wide bands of potential increase. and because the models relating the increase of C02 to the increase in temperature ( GCM) have a wide range of sensitivity. The error bands, of necessity, get wider. The wider the C02 projections ( SRES) the wider the error band at 100 years. The wider the sensitivity figures, the wider the error band. Nothing about the range of 7-82cm is surprising. The system is guaranteed to give wider bands than a naive estimate. That is the point. It shows our uncertainty about the future. Now, you are a government. You have to set standards for building near shorelines. You have to plan for disasters. Which kind of estimate do you want to use? Do you plan for 28-36cm like the naive estimate would dictate? Or do you plan for as much as 82cm? The planner in me says you plan for the “worst,” and worst of course carries with it assumptions, assumptions that could be wrong. If you plan for too little rise, you have huge costs that hit you later.
If you plan for too much rise, you may impose unnecessary costs in the present. But you can’t not plan. You have to model. you have to estimate. You can’t just shrug your shoulders. So, I see nothing wrong with producing estimates with wide error bands. That just indicates our lack of knowledge about the future levels. And, we have act under this cloud of uncertainty. What to do? Cut C02 or plan for a 82cm rise and establish building codes appropriately? Cut C02 which impacts everyone, or focus the costs on people who choose to live in low lands near water? Tax malibu.