The paper is currently in press at the Journal of Coastal Research and is provided with open access to the full publication. The results are stunning for their contradiction to AGW theories which suggest global warming would accelerate sea level rise during the last century.
“Our first analysis determined the acceleration, a2, for each of the 57 records with results tabulated in Table 1 and shown in Figure 4. There is almost a balance with 30 gauge records showing deceleration and 27 showing acceleration, clustering around 0.0 mm/y2.”
…
The near balance of accelerations and decelerations is mirrored in worldwidegauge records as shown in Miller and Douglas (2006)
Abstract:
Sea-Level Acceleration Based on U.S. Tide Gauges and Extensions of Previous Global-Gauge Analyses
J. R. Houston† and R. G. Dean‡ †Director Emeritus, Engineer Research and Development Center, Corps of Engineers, 3909 Halls Ferry Road, Vicksburg, MS 39180, U.S.A. james.r.houston@usace.army.mil
‡Professor Emeritus, Department of Civil and Coastal Civil Engineering, University of Florida, Gainesville, FL 32611, U.S.A. dean@coastal.ufl.edu
Without sea-level acceleration, the 20th-century sea-level trend of 1.7 mm/y would produce a rise of only approximately 0.15 m from 2010 to 2100; therefore, sea-level acceleration is a critical component of projected sea-level rise. To determine this acceleration, we analyze monthly-averaged records for 57 U.S. tide gauges in the Permanent Service for Mean Sea Level (PSMSL) data base that have lengths of 60–156 years. Least-squares quadratic analysis of each of the 57 records are performed to quantify accelerations, and 25 gauge records having data spanning from 1930 to 2010 are analyzed. In both cases we obtain small average sea-level decelerations. To compare these results with worldwide data, we extend the analysis of Douglas (1992) by an additional 25 years and analyze revised data of Church and White (2006) from 1930 to 2007 and also obtain small sea-level decelerations similar to those we obtain from U.S. gauge records.
Received: October 5, 2010; Accepted: November 26, 2010; Published Online: February 23, 2011
Sea-Level Acceleration Based on U.S. Tide Gauges and Extensions of Previous Global-Gauge Analyses, J. R. Houston and R. G. Dean
Discussion: (excerpt)
We analyzed the complete records of 57 U.S. tide gauges that had average record lengths of 82 years and records from1930 to 2010 for 25 gauges, and we obtained small decelerations of 20.0014 and20.0123 mm/y2, respectively. We obtained similar decelerations using worldwide-gauge records in the original data set of Church andWhite (2006) and a 2009 revision (for the periods of 1930–2001 and 1930–2007) and by extending Douglas’s (1992) analyses of worldwide gauges by 25 years.
The extension of the Douglas (1992) data from 1905 to 1985 for 25 years to 2010 included the period from 1993 to 2010 when satellite altimeters recorded a sea-level trend greater than that of the 20th century, yet the addition of the 25 years resulted in a slightly greater deceleration.
Conclusion:
Our analyses do not indicate acceleration in sea level in U.S. tide gauge records during the 20th century. Instead, for each time period we consider, the records show small decelerations that are consistent with a number of earlier studies of worldwide-gauge records. The decelerations that we obtain are opposite in sign and one to two orders of magnitude less than the +0.07 to +0.28 mm/y2 accelerations that are required to reach sea levels predicted for 2100 by Vermeer and Rahmsdorf (2009), Jevrejeva, Moore, and Grinsted (2010), and Grinsted, Moore, and Jevrejeva (2010). Bindoff et al. (2007) note an increase in worldwide temperature from 1906 to 2005 of 0.74uC.
It is essential that investigations continue to address why this worldwide-temperature increase has not produced acceleration of global sea level over the past 100 years, and indeed why global sea level has possibly decelerated for at least the last 80 years.
Full paper available online here
WUWT download (faster) here: jcoastres-d-10-00157.1
h/t to John Droz and to Dr. Willem de Lange
steveta_uk says:
March 28, 2011 at 8:38 am
“Latitude asks: If you have 5 gallons a minute going in, after you build the dam and it’s full, don’t you still have 5 gallons a minute going out…………..”
No, as lots of the water diverted by people is for drinking, irrigation, and other stuff that does not get back to the sea, but returns to the air directly.
==================================================
Nope Steve, it’s a wash…
..the same amount of water would be used for the same things – with or without the dam…
…and it all ends up in the same place
It has to do with precipitation, not dams
Looks like the authors of this report have been thinking along the same lines as we were (note their Figure 6 and this World Climate Report article)!
-Chip Knappenberger
>> David Archibald says:
March 28, 2011 at 3:31 am
Could someone else please get the Jason data and make it publicly available.
<<
I wonder how these satellites can claim resolution at 3mm when the orbital accuracy is 2 cm. Basing corrections for the data on more models is dubious at best but massaging the data is always a good gig if you can get it. Just ask the Team. The Poseidon Altimeter on the JASON satellite can measure the distance to maybe 5cm. Using the GRACE satellite for corrections?? WUWT?? Anyway, for those that remember their Greek mythology, Jason was sent on a quest for the Golden Fleece.. aka CAGW.
IPCC
“There was a rapid rise [in sea levels] between 15,000 and 6,000 years ago at an average rate of 10 mm/yr. No significant acceleration in the rate of sea level rise during the 20th century has been detected.”
In fact, if you recon that the Pleistocene ended 15,000 ybp, and that sea level reached modern levels 6,000 years ago (it didn’t), and that the change was approximately 140 meters, then the average rise per year about 15 mm, so 17 mm/y is a trivial difference. However, the evidence from many locations including Tasmania, Micronesia, Brazil and Texas indicates that sea level had reached a high stand about two meters above the present stand about 8,000 to 7,000 bp and has declined some since. That level and interval would have seen a average rise of about 18 to 19 mm/y, which does not include the effects of the Younger Dryas which saw increased ice cover. In fact then, between the end of the Younger Dryas and and the Early Holocene high stand the rates of rise would be even greater, possibly as much as 30 mm/y. The difficulty lies in successfully sorting eustatic changes and isostatic effects.
“I walk across the River Thames in Central London ……….”
Then, Latimer, I hope you have the correct navigation warning lights and have informed Canterbury of the second coming. 🙂
Cue the IPCC.
H/t Steven Goddard
“Precipitation has generally increased over land north of 30°N from 1900-2005, but has mostly declined over the tropics since the 1970s. Globally there has been no statistically significant overall trend in precipitation over the past century, although trends have varied widely by region and over time”
Exactly as one would expect from poleward shifting air circulation systems.
For some time I have been pointing out that the poleward drift ceased around 2000 and since then a more equatorward drift has been gradually and erratically establishing itself despite increasing CO2 concentrations.
I wonder when the ‘experts’ will catch up?
There is indeed an adjustment that sometimes is incorporated into presentations of global mean sea level. My google-fu isn’t quite up to snuff this morning so I wasn’t able to track down any specific number, but it may be the 1.6 mm that John Peter referred to.
The adjustment is to correct for the assumed lowering of mean sea level that occurs as the formerly ice-laden continents rebound due to isostasy. Tectonic adjustments are necessary for data from tide gauges because the point of reference (the shoreline) may be moving up or down. For satellite seal level data, the application of a glacial isostasy adjustment (GIA) means you’re no longer in the world of reality but instead in the world of matematical models. Instead of calculating what the mean sea level IS, one is calculating what the mean sea level MIGHT BE were the continental crusts not moving, assuming (a big IF) that the adjustment due to the GIA model is accurate.
So when it comes to global mean sea level, you have to know what the underlying assumptions and adjustments are. If you see a plot that claims to show sea level rise due to global warming, it’s safe to assume that half of the alleged rise is an artifact of this particular adjustment.
>>Stephen Wilde says:
March 28, 2011 at 10:50 am
“I wonder when the ‘experts’ will catch up?
<<
A couple of years after the billion dollar funding stream is turned on to study that.
Patrick Davis says:
March 28, 2011 at 3:48 am
Having lived in the Portsmouth, Havant, Hayling Island and Emsworth areas in southern UK for almost 1/3rd of the timeframe documented, albeit a bit earlier, this analysis, pretty much, confirms my observations.
Absolutely! At the start of the 19th century, because of problems with the French, it was decided to build a waterway all the way from Portsmouth to London, using canals and navigable rivers. Info here:-
http://www.welcometoportsmouth.co.uk/portsmouth%20arundel%20canal.html
The remains of the lock on the east side of Portsmouth are still there (used to moor small dingies now) and a complete lock, still holding water, can be seen near Chichester. At high tide the sea laps against the stonework much as it must have done almost 200 years ago. In fact, I’d say it’s probably LOWER now than then. Sea level rise? It’s all relative (quite literally).
There could just as easily be a net positive effect into the oceans of ground water rather than this perceived massive reduction of water into the oceans from irrigation etc. Most of the water used in rich countries is temporary – it comes into your home clean and it leaves your home dirty. What is lost is going to be a small fraction of the total amount, especially considering a typical toilet flush (which no doubt is additive if you’ve been eating and drinking).
Think of all the aquifers being pumped out, add back the waste water and I would bet the difference isn’t worth debating.
One problem that I have often encountered is that most people (and many scientists) confuse everyday language and scientific terms. Acceleration is one that is abused (confused) most often (spontaneous reaction is another). Anyone who has taken first semester physics, even without calculus, or first semester calculus, should well know what is meant by acceleration. However, the fraction of the general public who has studied these disciplines or remembered them is fairly small. Even if they remember the definition of acceleration, many cannot actually apply that knowledge.
How can something so simple be abused? Quite easily when people don’t think for themselves. Along with sea level change (very tricky – I just read the other day that the Japanese earthquake caused a global rise of 2 mm), representation of CO2 concentration is plotted in the same graph with the rate of CO2 emissions with axes adjusted so that the two curves overlap. Add in temperature and you have a trifecta.
In discussing AGW, one can discuss politics or science. I have found that two questions can often reveal whether it is useful discussing the science:
(1) Why is it warmer in the summer and colder in the winter? Most often wrong answer is that the sun is closer in the summer.
(2) What is meant by acceleration?
I have found that if someone can answer both of these questions, I can usually have a decent conversation about the science. If they cannot, I can only discuss politics (everybody is an expert!).
In the January, 1953 issue of Popular Science, I found this little nugget of information:
Dr. George F. Carter was quoted as saying, “Sea level the whole world over is five inches higher. Because this is the tail end of a glacial period, polar ice is melting and filling up the oceans. Future harbor works should be planned for an expected sea level rise of 24 inches within the next century.”
I’m pasting this from a post I wrote 10 months ago.
Have a gander.
Current sea level rise of the last 100 years has nothing to do with global warming.
steveta_uk says:
March 28, 2011 at 8:38 am
Latitude asks: If you have 5 gallons a minute going in, after you build the dam and it’s full, don’t you still have 5 gallons a minute going out…………..
No, as lots of the water diverted by people is for drinking……..
The only conclusion I can draw from your post is that you are contending that we are all p#ssing in the wind.
This is in direct contravention of the accepted theory that, the River Thames water, after passing through at least three people, finally reaches the North Sea.
And of course any older person living in a coastal area can plainly see these facts. There’s been no visible change in sea level in my lifetime, and I’ve always lived near the Pacific ocean. And if there was some tiny change in sea level, it would easily dealt with on human time scales. Humans move due to erosion and other natural forces all the time. There’s no great alarm as long as the change happens slowly over tens of years.
The hysteria crowd has been selling a change in sea level that is laughably great. Much more the kind of thing from a Hollywood movie, and much less reality. 20 ft in 10 years? LOL. Even 2 ft in ten years is LOL.
I doubt that other than meteors, tsunamis, and other sudden violent natural phenomena that there has ever been a time where sea level has changed on a human time scale as to warrant any human panic. These processes of glaciation, etc. just take far too long for any kind of human notice. Even 20 years seems a pace that would be unearthly fast, an yet more than adjustable to by humans.
Am I missing something here or is this not just ridiculously obvious. I can’t believe we even have to have this debate with these chicken littles.
If I may try to paraphrase the conclusions of this paper…
The rate of increase of sea level,
Gives fear-mongers no cause to revel.
There won’t be a trend
To a watery end
Till alarmists have gone to the devil.
I wouldn’t call this a bombshell. It has long been know that if you plot the graph you get a straight line. All this does is verify and certify that the line really is straight.
What sea level rise? Except for the temporary tsunami or hurricane induced swell, the sea level rise over the past 100 years is a crashing bore. A snail moves faster than that.
In geologic timescales, it might be more important to note where the continental shelves presently lie as the median point of sea levels. Presently underwater, that would indicate what level is consistent with the Ice Ages, where Earth has spent 80% of it’s time in recent geologic epochs.
Plan your port relocations offshore, and beat the competition.
Downscope.
“”””It is essential that investigations continue to address why this worldwide-temperature increase has not produced acceleration of global sea level over the past 100 years, and indeed why global sea level has possibly decelerated for at least the last 80 years.””””
Good question. If the globe is actually warming, then the sea level rise must accelerate because of thermal expansion. Is that correct, or am I missing something?
But this paper shows that the rise is slowing and they give lots of supporting evidence. I’m beginning to question past pronouncements that global warming is even happening. There’s sure a lot of money being paid out to people who say it is, isn’t there?
Looks like a depiction of vertical motions of tectonics, consolidation and subsidence due to extraction.
So adding a decrease in the rate of sea-level rise (which was not by much anyway) to the less than problematic melt in Himalayan Glaciers and the recovering snows of Mount Kilimanjaro, the Flooding in OZ being caused by a dam management error and we are getting a much broader global signal of climate change which is much more moderate than the alarmists claimed. In fact one could even state with a high degree of certainty that climate change is well within normal range of natural variability. The sort of natural variability which has been occuring for millenia. Natural climate change always has and always will occur. Why should we even attempt to tackle it?
How important is this finding for the AGW theory? Im asking bc it sounds pretty important in light of the scary sea level rise scenarios Ive read about…
“It is essential that investigations continue to address why this worldwide-temperature increase has not produced acceleration of global sea level over the past 100 years, and indeed why global sea level has possibly decelerated for at least the last 80 years.”
Maybe it has something to do with the fact that only urban areas have been warming. Most oceans lie ourtside of city limits.
>>RandomReal[] says:
March 28, 2011 at 11:52 am
One problem that I have often encountered is that most people (and many scientists) confuse everyday language and scientific terms. Acceleration is one that is abused (confused) most often (spontaneous reaction is another). Anyone who has taken first semester physics, even without calculus, or first semester calculus, should well know what is meant by acceleration. However, the fraction of the general public who has studied these disciplines or remembered them is fairly small. Even if they remember the definition of acceleration, many cannot actually apply that knowledge.
How can something so simple be abused? Quite easily when people don’t think for themselves. Along with sea level change (very tricky – I just read the other day that the Japanese earthquake caused a global rise of 2 mm), representation of CO2 concentration is plotted in the same graph with the rate of CO2 emissions with axes adjusted so that the two curves overlap. Add in temperature and you have a trifecta.
In discussing AGW, one can discuss politics or science. I have found that two questions can often reveal whether it is useful discussing the science:
(1) Why is it warmer in the summer and colder in the winter? Most often wrong answer is that the sun is closer in the summer.
<<
Random, ever heard of the southern hemisphere? So you're only half right. Lastly…overlap all you want. One thing I learned in 6th grade science was correlation does not imply causation. Might want to rethink your questions.
The first step of course is to assess what is really claimed by the science:
The acceleration is claimed for 1993 onward. Not for the past 100 years
You better be careful about focusing on particular regions. Note that they dont claim a universal rise
So, for example. The paper cited in this post appears to have focused on the US.
The US is interesting.
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/figure-5-15.html
Near-global ocean temperature data sets made available in recent years allow a direct calculation of thermal expansion. It is believed that on average, over the period from 1961 to 2003, thermal expansion contributed about one-quarter of the observed sea level rise, while melting of land ice accounted for less than half. Thus, the full magnitude of the observed sea level rise during that period was not satisfactorily explained by those data sets, as reported in the IPCC Third Assessment Report.
During recent years (1993–2003), for which the observing system is much better, thermal expansion and melting of land ice each account for about half of the observed sea level rise, although there is some uncertainty in the estimates.