Putting the Brakes on Acceleration

Guest Post by Willis Eschenbach

Various pundits and scientists keep talking about a threatened acceleration in the sea level rise. Here’s the IPCC Fourth Assessment Report:

Anthropogenic forcing is also expected to produce an accelerating rate of sea level rise (Woodworth et al., 2004).

The usual font of misinformation says:

Church and White (2006) report an acceleration of SLR since 1870. This is a revision since 2001, when the TAR stated that measurements have detected no significant acceleration in the recent rate of sea level rise.

Over at the inversely named “SkepticalScience” blog, which is inadequately skeptical, we find:

The blue line in the graph below clearly shows sea level as rising, while the upward curve suggests sea level is rising faster as time goes on. The upward curve agrees with global temperature trends and with the accelerating melting of ice in Greenland and other places.

The Guardian gets in their licks:

Sea levels are already on the rise as a result of increasing temperatures, because the oceans expand as they warm up, but until now scientists have had a poor understanding of how quickly ice sheets such as those in Greenland and Antarctica will begin to disappear.

Meanwhile, back in the world of reality we have the latest satellite data up to September of 2010:

Figure 1. Satellite-measured sea level rise. Errors shown are 95% confidence intervals. Data Source.

The smaller trend of the recent half of the record is statistically different from the larger trend of the first half. Will this reduction continue into the future? Who knows? I’m just talking about the past, and pointing out that we sure haven’t seen any sign of the threatened acceleration in the satellite record. Quite the opposite, in fact.

We now return you to your regularly scheduled warnings of global inundation from accelerating sea level rise …

w.

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When the sea level has already risen 400 feet since the end of the last ice age, the last ‘few millimeters’ is nothing but measurement error. Afterall, how do we know that 10,000 years ago the sea level didn’t really rise 410 feet? Or 390 feet? or +-20 feet of the Al Gore movie?
Engineering calls this measurement error.
When the “data” reality doesn’t meet up with the doom-saying science predictions, just change the dates, and or adjust the predictions — Junk science has a simple beauty all it’s own … LOL.
BTW, not criticizing the author, just what is going on.

hotrod ( Larry L )

The gentle rising curve in the chart immediately suggests to me a segment of a sine wave plot just beginning to nose over toward its peak, with a period of perhaps 120 -150 years.
As always our data history duration is so short we won’t be able to confirm that for a life time or two.
Larry

David L

I don’t think the average person knows what the technical definition of acceleration means. The term seems to mean, in common vernacular, simply an increase in the thing being observed.

AusieDan

The Australian government have warned local councils to get ready for much faster ocean rising in the future.
They have provided maps of threatened towns, villages and cities.
That puts many property owners in great difficulty as there are no buyers for property said to be threatened by rising sea levels.
Many people will have lost all their assets and be destitute if this nonesence is allowed to continue.
The only way out would be for someone harmed by this nonsense to take it to court.
It would need ample funds to pursue unless a class action could be started.
It would also require an able barrister who can understand some simple science.
Plus a judge who is experienced in examining evidence and is not afraid of kicking up a bit of a rumpus..

mjk

Absolutely spot on Willis. It is clear from the satellite measurements (when viewed upside down) that sea levels are in decline. I wish my share portfolio graph showed such a lack of acceleration. I would be rich!!! Must be a slow news day at WUWT to publish this analysis. Sea levels are headed in one direction: UP.
MJK

John S

But it’s all about the tipping points, runaway positive feedbacks, paradigm shifts, and the last straw that breaks the camel’s back. When the atmosphere reaches any one of those points, then all hell will break loose.
/sarcasm

James Barker

Has someone noticed that the moon is orbiting the Earth faster? Sea levels do have an accelerating rise twice every day 😉

Chris Smith

3 cm every 10 years. OMG, we are doomed! How can we possibly adapt to these extreme changes?
I don’t think I will be able to sleep tonight knowing that the sea level will be 8 microns closer to drowning me in my sleep.

Geoff

Hi Willis, thanks for continuing to point out the continuing nonsense about sea acceleration of sea level increase.
Before putting too much faith in the TOPEX/Poseidon figures, you may want to look at how the are calculated (adjusted?): see http://www.mdpi.org/sensors/papers/s6030131.pdf
It would be useful to have a formal reconciliation of the TOPEX/Posiedon numbers and the numerous conclusions in the literature of 1.5-1.9 mm per year (e.g., Wunch 2007, Leuliette 2009).

Dave in Delaware

This interview is a MUST READ in any discussion on sea level rise. Dr Mörner discusses trends in the 20th century (1.1 mm/yr), Pacific Islands such as Tuvalu, and below I have excerpted his discussion of satellite data ‘corrections’.
Interview: Dr. Nils-Axel Mörner
Claim That Sea Level Is Rising Is a Total Fraud
Tide gauging is very complicated, because it gives different answers for wherever you are in the world. But we have to rely on geology when we interpret it. So, for example, those people in the IPCC [Intergovernmental Panel on Climate Change], choose Hong Kong, which has six tide gauges, and they choose the record of one, which gives 2.3 mm per year rise of sea level. Every geologist knows that that is a subsiding area. It’s the compaction of sediment; it is the only record which you shouldn’t use.
Now, back to satellite altimetry, which shows the water, not just the coasts, but in the whole of the ocean. And you measure it by satellite. From 1992 to 2002, [the graph of the sea level] was a straight line, variability along a straight line, but absolutely no trend whatsoever
Then, in 2003, the same data set, which in their [IPCC’s] publications, in their website, was a straight line—suddenly it changed, and showed a very strong line of uplift, 2.3 mm per year, the same as from the tide gauge.
It was the original one which they had suddenly twisted up, because they entered a “correction factor,” which they took from the [Hong Kong] tide gauge.
It looks like it is measured from the satellite, but you don’t say what really happened. And they answered, that we had to do it, because otherwise we would not have gotten any trend!
http://www.climatechangefacts.info/ClimateChangeDocuments/NilsAxelMornerinterview.pdf
Dr. Nils-Axel Mörner is the head of the Paleogeophysics and
Geodynamics department at Stockholm University in Sweden.
He is past president (1999-2003) of the INQUA Commission
on Sea Level Changes and Coastal Evolution, and
leader of the Maldives Sea Level Project. Dr. Mörner has
been studying the sea level and its effects on coastal areas for
some 35 years. He was interviewed by Gregory Murphy on
June 6 for EIR. [June 22, 2007]

Looks like another travesty, ain’t that so Kevin?
My favorite ocean twins are these ones:
http://blog.sme.sk/blog/560/252537/sealevel.jpg

onion

what’s more funny, that this article is missing the slower sea level rise before 1992, or that some readers won’t even accept the article because they refuse to accept sea level satellite data.

Geoff

Sorry for the typos in the earlier post.
See Wunsch (2007) at – http://ocean.mit.edu/~cwunsch/papersonline/Wunschetal_jclimate_2007_published.pdf . Dr. Wunsch will never agree to be called a “skeptic” (and despite teaching at MIT I doubt he’s a Republican) but this paper is the souce of the quote “It remains
possible that the database is insufficient to compute mean sea level trends with the accuracy necessary to discuss the impact of global warming—as disappointing
as this conclusion may be”.
See Leuliette (2009) abstract at http://www.agu.org/pubs/crossref/2009/2008GL036010.shtml
See also Wöppelmann (2009) – http://www.agu.org/pubs/crossref/2009/2009GL038720.shtml

Mike McMillan

A few years ago, the U of Colo Jason/Topex chart was showing an overall 3.2 mm/yr rise, now it’s down to 3.1, and unless things pick up shortly, they may have to drop it to 3.0 mm/yr.
Also, the Jason 3 satellite is under construction by Thales Alenia, and will be launched in 2013. A subsequent satellite, Jason CS, is on the drawing board for 2017.

onion

I guess people might want to check the SkepticalScience article that the article quotes but does not link to:
How much is sea level rising?
http://www.skepticalscience.com/argument.php?p=3&t=104&&a=68

HR

You can possibly see the effects of the 1998 El nino and 2008 La Nina in the data, looks like these satellites are measuring something real.
I think the acceleration comes in an earlier period. It seems to coincide with the change over from gauges to satellite, something that worries me about this particular observation.
I’m not sure why anybody would expect acceleration in SLR over the satellite period. The global temp data isn’t showing an acceleration over the second half of the satellite period.
http://climexp.knmi.nl/data/icrutem3_hadsst2_0-360E_-90-90N_n_su_1992:2010a.png
Neither is ocean heat content
http://climexp.knmi.nl/data/inodc_heat700_0-360E_-90-90N_n_1992:2010a.png
Willis’s conclusion for this period sounds like it should also be the expectation of the climate scientists.
Willis are you assigning then IPCC acceleration to the wrong part of the record?

Jerejeva et al., 2008 show that 20th century sea level rise alternated between roughly 30-yr periods of ~3 mm/yr rises punctuated by roughly 30-yr hiatus periods…
Jerejeva, 20th Century Sea Level
The Jerejeva reconstruction goes back to 1700. The CU satellite data tie right into the Jerejeva reconstruction with a small static shift…
Jerejeva and CU Sea Level
The warm up from the Little Ice Age began in the 1600’s… Less than 100 years before sea level started its current rise (sea level has actually been rising since the Holocene transgression – But that’s a different story). CO2 started rising in about 1850.
Post hoc ergo propter hoc might be a logical fallacy… But… If the warming started before sea level started to rise… And both of those started before the CO2 started rising… It’s not very likely that CO2 caused the warming and the sea level rise.

Sam the Skeptic

David L @ 4:05 am —
I don’t think the average person knows what the technical definition of acceleration means. The term seems to mean, in common vernacular, simply an increase in the thing being observed.
mjk @ 4:17 am
I wish my share portfolio graph showed such a lack of acceleration. … Sea levels are headed in one direction: UP.
A very prescient comment there, David L. Who would have thought someone would have proved your point quite so succinctly and quite so quickly?

David

Willis, the Universty of Colorado graph you show does not look as flat as the Universitry of Colorado graph shown on the ENSO section of WUWT. Maybe my eyes are off , but if not WUWT?

Rob Findlay

I’m not a statistician, but surely the best tool for detecting time-trend anomalies is a statistical process control (SPC) chart? Or doesn’t it work on top of underlying trends?

Beesaman

I’m more worried about post glacial sea level rises stopping as that would be an indication that we are headed for the next glacial period. A whole lot more folk are going to die if it gets colder rather than warmer. I’m still wondering where all these sea levels are rising, I’ve visited quite a few seaside places here in the UK and the sea is still were I found it many, many years ago as a child. Maybe urbinisation and industrialisation of coastal areas has something to do with the land moving under our feet? Or maybe we only measure sea levels where we worry about them? It will be interesting to see what data our satellites come up with over the next few decades (once we are sure they are accurate enough).

Bruce Cobb

mjk says:
January 8, 2011 at 4:17 am
You might want to look up the term “acceleration”. Of course sea level has been rising, just as it has since the end of the last ice age, but that isn’t the point. On a graph, an acceleration would appear as a parabola, arcing upwards. But, if you put a straight edge on that line you will see just the opposite. Oops.

Sam Hall

AusieDan says:
January 8, 2011 at 4:06 am
The Australian government have warned local councils to get ready for much faster ocean rising in the future.
They have provided maps of threatened towns, villages and cities.
That puts many property owners in great difficulty as there are no buyers for property said to be threatened by rising sea levels.
##############################
Chance for somebody with money to pick the property up cheap and hold it until the truth is out. A greenie would never do that, would they?

Stacey

My question is how, where and when do they measure the sea level.
The above graph as a range of +- 20mm I would have thought that the surfaces of the oceans are constantly changing.
Am I missing something?

Bill Illis

Good find Willis.
A polynomial fits the data better than a linear trend. A polynomial extension of the data only gives modest rise in sea level by 2100.
I downloaded the Aviso sea level data (which is a little more up to date, includes the Envisat satellite and includes all the adjustments that should be done like seasonality as well) in addition to the University of Colorado.
http://www.aviso.oceanobs.com/en/news/ocean-indicators/mean-sea-level/products-images/index.html
Aviso as well is not a linear trend.
http://img3.imageshack.us/img3/6379/sealevel2010.png
Extending out both to 2100, we see only 6 inches of sea level rise in Aviso by 2080 after which it peaks (and the University of Colorado data shows a peak occuring a little too soon so perhaps Aviso is better).
http://img233.imageshack.us/img233/4504/sealevel.png

Alex the skeptic

Beesaman says:
January 8, 2011 at 5:49 am
…I’ve visited quite a few seaside places here in the UK and the sea is still were I found it many, many years ago as a child…
=====================================================
Same here in tiny Malta, middleof the mediterranean sea. No indication of any visually identifiable signal of any sea-level changes whatsover, positive or negative. Our old traditional fisherman would definitely notice since these have made many markings, boat hooking points on the rocks, steps cut in granite etc…. NO CHANGE.
Sarc on: Maybe it’s because we do not have glaciers….LOL.

Edim

SL is very important issue and it will probably be the issue to wake people up. It is obvious that it already stopped rising and it will be dropping soon, much faster than it rose in the last few decades.

Kev-in-UK

re ‘acceleration’ as used by the warmists – this is typical ‘get out of jail free’ card used by propagandist types to ensure the original fact of continuous (i.e. since LIA) sea level rise is ignored. Instead of describing decadal (or whatever) changes in rates of SL rises, they use the term acceleration to be deliberately alarmist. The truth is (from this article) that acceleration is slowing – but I wonder how many MSM articles will ever say that!
I suspect the satellite data is pretty useless (+/- 20mm is not that useful when one can do real measurements at harbours etc) but yet again it doesn’t exactly get prime media coverage because it does not show what the alarmists want!

Olen

Sea level rise seems to be more policy than science. Will the earth they claim to be saving cooperate? We know tax hungry politicians will, if elected.

Please see:
TOPEX-Poseidon Radar Altimetry:
Averaging the Averages
by John L. Daly (5 Dec 2001)

John Daly died 2004. This article is very well written and informative. I have some knowledge of radio and radar and think most of what John wrote almost 10 years ago is correct.
Agust

If you separate the Topex data from the Jason data and plot trend lines you can see that there has been a lowering of the rate of rise. The change may be due to the satellite differences.

Dagfinn Reiersøl

hotrod ( Larry L ) mentions sine wave plots. I was just thinking of a slightly more general question about trends. If, hypothetically, you have several independent climate phenomena, each following a natural sine wave, then mathematically one fourth of these will be accelerating upwards at any point in time. Similarly, one fourth will be accelerating downwards. So given the various natural climate cycles, the odds should be pretty good of finding a trend that either seems to be increasing exponentially or looks like it’s in a “death spiral”. It’s almost surprising that the best example anyone can find is arctic sea ice.

Ralph

I will post this again, if you don’t mind.
The evidence from the Mediterranean (which no tides to confuse the issue) counts against sea level rise.
There are deep undercuts on the cliffs around Greece and Turkey, which lie precisely on the sea level (caused by wave action). Now I did think these cliffs may be ‘recent’ due to erosion. However, I have now found deposited curtains of calcite deposits, from streams flowing over the cliff-top, with layered deposits 25cm deep. This means these cliffs have been a feature in this state (with undercuts at sea level) for many centuries.
Now unless one proposes that land movement is exactly in synch with sea level rise, for the erosion to be exactly at sea level, the evidence seems to suggest that sea levels have not changed for between two and five centuries (depending on how long it takes to deposit 25cm of calcite, from a stream that can only flow in the winter months).
And these undercuts are precisely at sea level. There was a glass sea a couple of months ago, and the sea was sitting just on the lower platform of the undercut. Within 5cm.
.
This is in addition to Greek and Roman ports being at or above sea level, all over the eastern Med. Now you might argue land rise for the above sea level ancient ports – but you cannot argue the same for the cliff undercuts, otherwise you would have other undercuts left high and dry above the present sea level.
.

KD

onion says:
January 8, 2011 at 5:10 am
I guess people might want to check the SkepticalScience article that the article quotes but does not link to:
How much is sea level rising?
http://www.skepticalscience.com/argument.php?p=3&t=104&&a=68
________________________________________
As with mjk, I suggest you look up the definition of acceleration. The chart in the article you link to clearly shows EXACTLY the point Anthony was making, i.e. that there is no acceleration in the rate of sea level rise.
As tarpon pointed out in the first comment, the VERY SMALL rate of rise at this point, relative to the significant change over the recent (in geological terms) past is measurement error. Now even that rate seems to be slowing, so where’s the concern?
Oh, and interesting that the article you linked to only shows the data up to 2005, omitting the data since then. I wonder if that could be because the data since then, as shown by Willis above, shows even More clearly that the rate of sea level rise is DECELERATING, not accelerating?
Hmmmmmmmmmmm… a bit of cherry picking methinks.
KD

latitude

mjk says:
January 8, 2011 at 4:17 am
Sea levels are headed in one direction: UP.
================================================
and there’s not one thing we can do about it…..
….does that make you wet your pants

PJB

Over the satellite record, the rise rate is trending down and perhaps the ocean cooling of the last decade accounts for some of that?

Jim Cole

Rather than getting all geeky about how closely we can measure sea level to mm precision, why not take some clues from geology and look at the big picture?
Search “Holocene sea level” and follow some of the links. The rapid melting of continental ice sheets after the glacial maximum actually peaked about 6000-4000 years ago when sea level was roughly 2 METERS higher than today.
This evidence comes from wave-cut terraces and stranded corals that are presently sitting high and dry above the surf. These sites were not affected by isostatic rebound or tectonic uplift.
The Antarctic probably held substantially less ice during that Holocene Climatic Optimum when “global temperatures” were several degrees warmer than today.

Jimbo

mjk says:
January 8, 2011 at 4:17 am
Absolutely spot on Willis. It is clear from the satellite measurements (when viewed upside down) that sea levels are in decline. I wish my share portfolio graph showed such a lack of acceleration. I would be rich!!! Must be a slow news day at WUWT to publish this analysis. Sea levels are headed in one direction: UP.

Look at this graphic graphic showing sea level rise since the end of the last ice age. Initially it looks quite alarming then gets less so over time.

Douglas McCormack

Very interesting, but if you take the longer period of observed decadal sea level rise, even the figures quoted are a slight exaggeration I would suggest. According to S. J. Holgate, a recognised world authority in geophysical research at the UK-based Proudman Oceanographic Laboratory in Liverpool, in his paper published in 2007, the following results represent the most comprehensive measurements of decadal sea-level change rates during the 20th century.
Between 1904 and 1953 global sea levels rose by 2.03 mm per year, whereas from 1954 to 2003 they rose by only 1.45 mm per year, giving an annual mean rate of 1.74 mm per year over the 100 years to 2003, or seven inches per century. Importantly, there was no increase in the rate of change over the whole century, indeed, they slowed down in the fifty years to 2003. These numbers have, incidentally, been fully accepted by the scientific establishment!

James Sexton

mjk says:
January 8, 2011 at 4:17 am
Absolutely spot on Willis. It is clear from the satellite measurements (when viewed upside down) that sea levels are in decline. I wish my share portfolio graph showed such a lack of acceleration. I would be rich!!! Must be a slow news day at WUWT to publish this analysis. Sea levels are headed in one direction: UP.
========================================================
As stated earlier, congrats to David L for showing a predictive prowess and having a finger on the pulse of alarmists. Also to MJK for having a desire to be posted on WUWT over a desire to type “acceleration define” in his/her search bar.
I’m feeling a bit generous this morning, so MJK, this is your lucky day.
Definitions of acceleration (n)
ac·cel·er·a·tion [ ak sèllə ráysh’n ] Audio player
1. increase in speed: the rate at which something increases in velocity
2. increase in rate of progress: an increase in the rate at which something happens or develops
3. act of accelerating: the act of accelerating, or the process of being accelerated
Synonyms: speeding up, stepping up, hastening, hurrying, quickening, rushing
Please note the synonyms (words that have same or similar meanings).
In Willis’ graph, did you see any quickening or speeding up? No? So sea level rise isn’t accelerating. But, you’re probably more focused on the sea level rise. The fact that the sea level is rising at all probably causes you much concern and alarm. This is a sad but known phenomenon. You see, when we exit a glaciation, (that’s where much of the earth is covered with glaciers), the dastardly glaciers melt on us! In spite of some heroic efforts to sequester the melted ice from the sea, inevitably, we fail, and the melted water making it to the sea raises the sea level.
Go here and scroll down to see a graphical representation of historic sea levels.
http://www.johnstonsarchive.net/environment/sealevel.html

Craig Loehle

There you go again, ruining a perfectly good narrative with that silly “data” stuff. If any of the sea level rise is due to warmer ocean water (and I think we know the answer to that…) then the flat to cooling temperatures of the ocean (Loehle, C. 2009. Cooling of the Global Ocean Since 2003. Energy & Environment 20:99-102.) would make the sea level rise curve start to turn down, as you show.

Steve Keohane

Jim Cole says: January 8, 2011 at 7:24 am
Rather than getting all geeky about how closely we can measure sea level to mm precision, why not take some clues from geology and look at the big picture?
Search “Holocene sea level” and follow some of the links. The rapid melting of continental ice sheets after the glacial maximum actually peaked about 6000-4000 years ago when sea level was roughly 2 METERS higher than today.

I know I have read of archeological digs along the Gulf Coast c.>2000 years ago, and the shore line was ~50 miles north of today’s as the Gulf was 2 meters higher.

alec, aka Daffy Duck

David wrote: “… the Universty of Colorado graph you show does not look as flat as the Universitry of Colorado graph shown on the ENSO section of WUWT. Maybe my eyes are off , but if not WUWT?”
What gets me is the ‘diagonal black line’ on that graph…to me the trendS look like this:
http://sitelife.runnersworld.com/ver1.0/Content/images/store/13/9/dd8b7779-094f-4350-8980-aedf0c0f542b.Medium.jpg

Jim Clarke

One thing that is always missing from these discussions is the fact that coastlines are not static. Even if we leave out subsidence and uplift, other factors have an impact on the ‘height of the coast. Plants are constantly trying to build up the land along the shore. Waves can can deposit sediment along the coast or take it away, depending on many different factors.
Bangladesh, one of the supposedly more vulnerable places on Earth to sea level rise, has seen a tremendous gain in ‘dry’ land area due to these processes.
It is not scientifically feasible to take the current rate of sea level rise, project it out hundreds of years, then draw maps of flooded regions. It won’t happen that way.

Laurie Bowen

Do continents “float” ?? . . . . I know clouds do . . . and they are heavy especially right before it rains!

Craig Moore

Methinks the gloom and doom crowd have decimal dust emitting from their carbon wands. BOO!!!!!!!!!!!!!!!!!!

Mike Haseler

onion says: what’s more funny, that this article is missing the slower sea level rise before 1992, or that some readers won’t even accept the article because they refuse to accept sea level satellite data.
Orion, you clearly have little understanding if you make that type of comment. Let me give you a very simple example of the problem. I was recently trying to find the level of the sea at the Eastern Terminus of the Antonine wall when it was built. After contacting the best authorities on the subject they were unable to tell me whether the sea level had risen or fallen. The problem is that the last ice age depressed the area of Scotland and the land mass itself has been rising. In addition there have been sea level changes. The result is that not only should you expect long term sea level change, but you should also expect long term land level change – particularly in a region close to plate boundaries.
If you want to see evidence for land level change just pick up a rock. There’s a 100% certainty that it was formed when the land was at a different level – otherwise how e.g. would limestone rise above sea level? Or granite, or metamorphic stones, or sandstone become compacted – and if it’s mudstone then where is the mud now?
Land level is constantly changing. Some land masses are rising and some are falling and how anyone thinks it is possible to get an accurate measure of sea level from a few tide gauges is beyond me because there is no way to tell whether a change in the level of the gauge is due to a rise/fall in the land and/or a rise/fall in the sea level.

JohnH

Its more understandable if you use ‘Rate of change’ instead of acceleration.
And the rate of change is decreasing.

Steve Keohane

Here is one reference to higher sea levels in the Holocene, geologic, not archeologic.
http://academic.research.microsoft.com/Paper/13400808.aspx