Guest Post by Willis Eschenbach
Much has been made in AGW circles of the sea level forecast of Vermeer and Rahmstorf, in “Global sea level linked to global temperature” (V&R2009). Their estimate of forecast sea level rise was much larger than that of the IPCC Fourth Assessment Report (FAR). Their results have been hyped at places like RealClimate as being much more realistic than the IPCC estimates.
So I figured I’d see how Vermeer and Rahmstorf are faring to date. Their results for each of the IPCC “scenarios” are archived here, and the first thirty years of their estimates are presented along with nearly twenty years of actual observations in Figure 1.
Figure 1. Satellite-based sea level observations (blue line), along with the V&R2009 sea level estimates corresponding to the various IPCC future scenarios. Sea level observations from the University of Colorado. PHOTO SOURCE
So … how are the V&R2009 predictions holding up?
Well, … or to be accurate, not well. As you can see, the observations showed an actual sea level rise that is below the lowest of the V&R2009 estimates from the lowest of the IPCC scenarios.
At present, assuming that the distance between their “best” estimate and their “lower” estimate is two standard deviations, the data is now more than four standard deviations below the “best” V&R2009 estimate.
So in answer to how their forecasts are faring, the answer is … very poorly. Abysmally, in fact. Actual observations are lower by four standard deviations than the V&R2000 “best” estimate, and are two standard deviations lower than their “lower” estimate.
w.
Technote 1 – The Colorado folks have recently included a 0.3mm/year increase in sea levels in their results. They say (possibly correctly) that this is necessary to adjust for the sinking of the ocean floor with the increasing weight of sea water from the melting at the end of the last ice age. However, since neither the IPCC nor the V&R2009 figures include that adjustment, I have not included it in this analysis so that we can compare apples to apples.
Technote 2 – I have aligned the Colorado observational results so that their trend line is zero in 1990, in order that they can be compared directly with the V&R2009 results, which have 1990=0 as their starting point. This also aligns the starting observations with the V&R2009 “best” estimate.
Technote 3 – some folks felt that my last post, “Yes, Virginia, there is an FOIA” was short on science content and long on passion … hey, what can I say, I’m a passionate guy. I trust this post will redress the balance in their estimation.
[UPDATE] Steven Mosher has graciously pointed me to a stunning disassembly of V&R2009, at the blog Climate Sanity. Makes my effort above look simplistic by comparison. He shows, among other things, that the V&R formula for sea level leads to ridiculous results when it is fed with actual data rather than IPCC scenarios … quite lethal to their claims. Well done, that man. – w.
Worth archiving and updating annually or biennially.
speaking of archiving and updating, does someone maintain an updated archive of all the predictions that have been made, with current measurements compared to predictions? It might be nice of Anthony would add such an archive, with a hot link to the right alongside the ENSO link and others.
I’m not understanding the point of the .3mm/year adjustment. We live on LAND and if .3mm of water is added each year and the sea floor sinks .3mm a year then all of us on LAND could care less.
If I run at 10 mph and the treadmill I’m on is going at 10 mph then I’ve moved no where. I’m not going to run from Los Angeles to New York if the treadmill I’m on is going in the opposite direction at the same speed. But with the proper ‘adjustment’ I can scare the people in New York that I’ll be there way way way way way way way sooner than reality.
Jared says:
July 3, 2011 at 5:54 pm
I’m not understanding the point of the .3mm/year adjustment.
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Jared, the slope/trend has been about .3mm/year, up until a few years ago.
Then it stopped, like temperatures, and started going the other way – down
This is the way they get their trend back from no trend…………..
I would note that measurements claim that both the Atlantic and the Pacific are getting wider due to the ridges in each expanding. Is that shrinking the continents or squeezing them upward?? They need another correction for this!! Then again, maybe the land ISN’T rising due to the ocean bed getting deeper. They claim there is subduction also which could raise the continents and THAT is what is causing the rising. Maybe the land is rising without the basins getting deeper!! Of course, there is a fixed amount of material getting moved around here so it may really be zero sum and none of the above is actually happening on a long term basis. We are only seeing minor adjustments in the short term that reverse or are balanced over long periods!!
Isn’t all this poorly measured information a wonderful thing for a poorly measured hypothesis of feedbacks causing a problem with temps??
So …. we’re not doomed?
Hoser says:
July 3, 2011 at 2:08 pm
Oops, maybe we have a little problem there. US Dept. of Education, indoctrination of our kids at the expense of teaching. Cybersecurity, eventual replacement of internet with powerline broadband they control, probably like China.
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So basically the socialists/greens/leftists own the media, education, the UN, most governments and much of the US gov.
Quite the task to get through that. Not impossible, but we’ll all need to do some heavy lifting.
LazyTeenager says:
July 3, 2011 at 4:45 pm
…”you do understand don’t you that if the sea floor falls the continents rise and vice versa .”…..
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Assuming your theory is true, what causes the rise and fall?
The Ups and Downs of Sea Level on the Japanese coast for 1906-2010:
http://www.data.kishou.go.jp/shindan/a_1/sl_trend/sl_trend.html
Philip Clarke says:
July 3, 2011 at 4:43 pm
“Speaking of ‘science content’, the sea level metric cited by V&R is from GRACE, (their ref 16). As they say,
Another semiindependent test is provided by the satellite
sea-level record updated from ref. 16 that started in 1993 and
now provides 16 years of data (up including 2008),”
As I understand it the GRACE system was not launched until 2002 and it measures gravity not sea level elevation.
I thank and congratulate Willis for this report on his interesting and important work. However, there is a logical shortcoming in the argument by which he reaches his conclusions that should be addressed.
In Willis’s Figure 1, the yellow curves are examples of the entities that the IPCC calls “projections” (aka “scenarios”) but the entities which are logically comparable to observations are the entities that one calls “predictions.” While Figure 1 compares a number of projections from V&R’s model to a sea level time series, projections and observations are not logically comparable for unlike a prediction the set of projections does not state a falsifiable claim.
LazyTeenager says:
July 3, 2011 at 4:45 pm
“… but you do understand don’t you that if the sea floor falls the continents rise and vice versa .”
I’m only a geologist. Maybe you could explain this new theory to me? Maybe give some examples of where this is happening? Or is it just a model output?
LazyTeenager says:
July 3, 2011 at 4:45 pm
1DandyTroll sarcs:
July 3, 2011 at 2:33 pm
So, essentially, when the ocean floor sinks the sea rises even more. I can really visualize it: Mann and his schtick rising to even greater heights by the second in a pool of quicksand.
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The sarcasm obscures your meaning but you do understand don’t you that if the sea floor falls the continents rise and vice versa .
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DUH. But it is not that simple, lazy teenager.
[Not sure why you would want that insulting, stupid moniker but hey who am I to judge.
Sea level is a very very VERY complicated thing…and it has much much MUCH more to do with ocean floor sinking (or rising) and continent action of the same.
Much, much, MUCH more.
Stop being so lazy.
Chris
Norfolk, VA, USA
Septic Matthew says:
July 3, 2011 at 5:30 pm
try this (as a starter):
http://www.c3headlines.com/predictionsforecasts/
Thanks again for another great post Willis! Re: your post on Tuvalu not sinking, I had the irritating displeasure of sitting next to a fellow who is paid to teach the people there how to deal with ‘climate change’, i.e. sinking, at a dinner the prior night to your post. Ironic.
kuhnkat says:
July 3, 2011 at 6:06 pm
I would note that measurements claim that both the Atlantic and the Pacific are getting wider due to the ridges in each expanding. Is that shrinking the continents or squeezing them upward?? They need another correction for this!!
I think you are right. They also need to consider that virtually all intersections of the ocean with land are on ground that slopes into the water. Therefore to increase sea level at a constant rate, an ever- increasing amount of water would have to be added to compensate for the wider ocean surface proportionate to the increasing depth. /sarc
tokyoboy says:
July 3, 2011 at 6:42 pm
Is that a 60-year cycle? With a variation of about 60mm (not 300mm) over 100 years?? You mean, it’s *not* worse than we thought?
Willis,
I think you might want to disambiguate a couple of issues.
1. Getting the forecast wrong because the model is wrong
2. getting the forecast wrong because the inputs ( predicted temperature) is wrong.
That is, instead of feeding their model Projected temps, feed it observed temps.
That’s a test of the model. As it stands two issues are in play.
Have you had any luck recreating their model?
If the ocean floor were rising, would the U Colo folks introduce a 0.3mm/yr decrease in sea level to compensate for it?
To ask the question is to know the answer.
M Carpenter says:
July 3, 2011 at 2:38 pm . . . why is the angle . . .
I guess you missed the theme of this post being about sea level and that the ice your link speaks of is floating ice?
At the end of a glacial event the lower latitude and lower elevation ice will melt initially. Once the melting of this ice proceeds and leaves only high latitude and high elevation ice there isn’t going to be a lot of ice left that can easily be melted. Visit Seattle – look at “the Mountain.” Mt. Rainier still has glaciers (elevation) while the massive Puget Lobe (sea level) of the Frasier Glaciation is long gone. Oceans were about 400 feet lower then but the rise was rapid. Hope this helps.
http://www.dnr.wa.gov/ResearchScience/Topics/GeologyofWashington/Pages/lowland.aspx
Shanghai Dan says: about Neah Bay, Washington
July 3, 2011 at 2:13 pm
That might just be a sign that the coast of Washington is warping up as this is an active plate margin. If you are young enough and live to be elderly you might be around when the locked sections fail and the coast sinks about 10 feet. Then again, this might happen tomorrow or next week. Spend an hour at the PANGA site:
http://www.geodesy.cwu.edu/
steven mosher says:
July 3, 2011 at 9:52 pm
Very nice, Mosh, good questions. I’ve been moving quite fast and haven’t looked at their model. Just back from a gorgeous night out on the banks of the river, 70°F (20°C), fireworks, a constant parade of geeks and freaks walking and bicycling and driving and biking and wheelchairing past. One of the most perfect 4th of Julys in my memory.
As time permits I may take a look at their model. I have lots going on.
w.
Willis,
model looks pretty simple. wonder why they just dont supply code
“This paper adds to the evidence that we could have sea level rise by the end of this century of around 1 meter and a good deal more in succeeding centuries.” ))
And where is all this evil carbon based energy to come from to “pollute” the atmosphere you moron.??????…..(stand back, take a deep breath)
regards
Mike Jowsey says: July 3, 2011 at 9:48 pm
“Is that a 60-year cycle? With a variation of about 60mm (not 300mm) over 100 years??”
Well our Met Office says just two things:
1. There’s no long-term trend in the past >100 years.
2. About 20-year cyclic oscillation is evident.
The graph you present here seems to show a precipitous drop at the end which is more to do with your scaling than anything else
http://climate.nasa.gov/keyIndicators/index.cfm#seaLevel
This is NASA/NOAA version of the same data it does show a dip starting near the beginning of 2011 which you may have heard had a cool start much the same as as 2008 did (it shows a similar dip and if you look at 1998 (in the Colorado graph) you see a spike.
http://sealevel.colorado.edu/files/current/sl_ib_ns_global.png
It is a thermal signature as sea level rise is part thermal expansion and part melting ice and yes 2011 started cool, but it is warming and the Colorado data shows that as the small arrest in the most recent of their data, which strangely seems to not show in your version.
More interesting would be why your graph shows sea level dropping to the equivalent of 2007 levels when NOAA’s only have a dip equal to late 2010 with both these points being well above 2007, 2008 or 2009 levels.
It is interesting to see you say the IPCC estimates are “realistic ” I would actually agree with that, but I think many others here wont.
@Mike g says:
July 3, 2011 at 1:26 pm
re: @fredb
Yes, what a silly comment. It’s been upwards since the last ice age. And, we’re supposed
to be alarmed that it continues to do what it’s done for thousands of years?
I hope you mean up ~2000 years ago, or don’t you count that bit
http://commons.wikimedia.org/wiki/File:Holocene_Sea_Level.png