Below: North Carolina’s Albemarle Sound.
Note marker at 36N -76W.
First the Press Release from the University of Pennsylvania:
North Carolina Sea Levels Rising Three Times Faster Than in Previous 500 Years, Penn Study Says
October 28, 2009
PHILADELPHIA –- An international team of environmental scientists led by the University of Pennsylvania has shown that sea-level rise, at least in North Carolina, is accelerating. Researchers found 20th-century sea-level rise to be three times higher than the rate of sea-level rise during the last 500 years. In addition, this jump appears to occur between 1879 and 1915, a time of industrial change that may provide a direct link to human-induced climate change.
The results appear in the current issue of the journal Geology.
The rate of relative sea-level rise, or RSLR, during the 20th century was 3 to 3.3 millimeters per year, higher than the usual rate of one per year. Furthermore, the acceleration appears consistent with other studies from the Atlantic coast, though the magnitude of the acceleration in North Carolina is larger than at sites farther north along the U.S. and Canadian Atlantic coast and may be indicative of a latitudinal trend related to the melting of the Greenland ice sheet.
Understanding the timing and magnitude of this possible acceleration in the rate of RSLR is critical for testing models of global climate change and for providing a context for 21st-century predictions.
“Tide gauge records are largely inadequate for accurately recognizing the onset of any acceleration of relative sea-level rise occurring before the 18th century, mainly because too few records exist as a comparison,” Andrew Kemp, the paper’s lead author, said. “Accurate estimates of sea-level rise in the pre-satellite era are needed to provide an appropriate context for 21st-century projections and to validate geophysical and climate models.”
The research team studied two North Carolina salt marshes that form continuous accumulations of organic sediment, a natural archive that provides scientists with an accurate way to reconstruct relative sea levels using radiometric isotopes and stratigraphic age markers. The research provided a record of relative sea-level change since the year 1500 at the Sand Point and Tump Point salt marshes in the Albemarle-Pamlico estuarine system of North Carolina. The two marshes provided an ideal setting for producing high-resolution records because thick sequences of high marsh sediment are present and the estuarine system is microtidal, which reduces the vertical uncertainty of
paleosea-level estimates. The study provides for the first time replicated sea-level reconstructions from two nearby sites.
In addition, comparison with 20th-century tide-gauge records validates the use of this approach and suggests that salt-marsh records with decadal and decimeter resolution can supplement tide-gauge records by extending record length and compensating for the strong spatial bias in the global distribution of longer instrumental records.
The study was funded by the National Oceanic and Atmospheric Administration Coastal Ocean Program, North Carolina Coastal Geology Cooperative Program, U.S. Geological Survey and National Science Foundation.
The study was conducted by Kemp and Benjamin P. Horton of the Sea-Level Research Laboratory at Penn, Stephen J. Culver and D. Reide Corbett of the Department of Geological Sciences at East Carolina University, Orson van de Plassche of Vrije Universiteit, W. Roland Gehrels of the University of Plymouth, Bruce C. Douglas of Florida International University and Andrew C. Parnell of University College Dublin.
I was curious, because this seemed a bit “off” to me based on other data that I’ve seen. So I went to the University of Colorado Sea Level data server and entered the coordinates for Albemarle Sound (36N -76W or in their usage 36N 284W).
The graph they serve up looks like this:
It’s low resolution, but does look rather flat. Fortunately they provide the data with the plot. You can read all about the Topex/Poseidon data preparation here.
I took that raw data and plotted it here in an expanded size and did a trend line, shown below:
The result was surprising. A slight negative trend.
I chose a different location to get closer to Pamlico Sound, also cited in the study. Unfortunately the interactive tool at UC is coarse on lat/lon and the closest I could get was 35N -76W, just off the outer banks.
The data from that point is plotted below. The source data for 35N -76W is available here.
Apologies for the slight cosmetic differences in line size between the two graphs. I had a computer reset between sessions and lost some settings.
So, if there is 3mm rise per year recently, since 1992, we certainly can’t see it. I can’t say anything for the other years in the study.
But in the press release they say:
The rate of relative sea-level rise, or RSLR, during the 20th century was 3 to 3.3 millimeters per year, higher than the usual rate of one per year.
If that is true, then the rate appears to have slowed significantly in the late 20th century to present. For 35N, -76W, the 1.12mm/yr rate certainly looks like the “…usual rate of one per year”.
Constant rate of sea level rise of approx 1.9mm pa throughout the last 100 years
In a definitive paper about sea level change, “Sea level budget over 2003-2008: A re-evaluation from GRACE space gravimetry, satellite altimetry and Argo” (Global and Planetary Change Vo 65, Issues 1 – 2 , January 2009, Pages 83-88 preprint here http://sciences.blogs.liberation.fr/home/files/Cazenave_et_al_GPC_2008.pdf ))
Dr Anny Cazenave et al conclude:
“Over 2003–2008, the GRACE-based ocean mass has increased at an average rate of ∼1.9 mm/yr (if we take the upper range of possible GIA corrections as recommended by Peltier, submitted for publication). Such a rate agrees well with the sum of land ice plus land water contributions (i.e., GRACE-based ice sheet mass balance estimated in this study, GRACE-based land waters plus recently published estimates for the current glacier contribution). These results in turn offer constraints on the ocean mass GIA correction, as well as on the glacier melting contribution.”
The authors also note that since 2006 the rate of increase seems to have plateauxed, an observation since confirmed by others.
Twenty years ago in 1990 Trupin and Wahr in a highly rigorous paper (A Trupin and J Wahr “Orthogonal Stack of Global Tide Gauge Sea Level Data” pps 111 to 117 in Dennis D McCarthy and William Carter (eds) Variations in Earth Rotation Geophysical Monograph 59 American Geophysical Union and International Union of Geodesy and Geophysics Vol 9 1990) found:
“Global averages of tide data, after correcting for the effects of post glacial rebound on individual station records, reveal an increase in sea level over the last 80 years of between 1.1mm/yr and 1.9mm/yr, …. with a preferred value of 1.75mm/yr.”
The value of approx 1.9mm/yr accords with other estimate published around that time.
The conclusion from these published papers, both rigorous and definitive, is that the rate of increase of the ocean mass has been constant for over 100 years at approximately 1.9mm/yr.
If the ocean mass has been increasing at the constant rate of approximately 1.9mm/yr for the last 100 years, its temperature cannot have been increasing at an increasing rate as the IPCC hypothesised. This is because warmer water occupies a greater volume that cooler water, other things being equal. Hence there is no trace of any increased temperature in the total mass of the oceans that could be attributable to AWG as the IPCC hypothesised.
In Australia’s Commonwealth Parliament, The Commonwealth Government in response to Senator Fielding stressed that ocean warming is the best test of the IPCC AGW hypothesis and that time periods of 50 years or longer are required to discern long term trends in climate with confidence.
Throughout the past 100 years GHGs have been increasing but ocean temperatures have been rising at a tiny constant rate of 1.9mm/yr which is entirely attributable to non GHG variables.
The Government’s nominated test of the basis for the cap and trade bill shows clearly that there is no empirical basis for the bill.
“This jump appears to occur between 1879 and 1915, a time of industrial change that may provide a direct link to human-induced climate change.”
I thought there was greater industrial change and output between 1914/18 and 1939/45. This may not be a true measure of overall industrial output, but as an example, the amount of aircraft produced between 39/45 still has not been exceeded and that is including all the years since 1945.
I realize that it’s easy to attribute stuff like this to us because we have the likes of Mann on our payroll, but UPenn != Penn State.
REPLY: fixed
Why on earth is anyone faffing around with a suspected increase in sea level of a millimetre or so? Does anyone really expect sea levels to remain stationary over any given period of time? Why the sudden clutching at straws to try and prove what we already know – the climate is continuing to change, as are the spread of oceans and land masses (as they always have done). I can’t for the life of me understand why so much importance is placed on the infinitesimal span of time in the scheme of things that humans have been around, when the “changes” we may be witnessing are so small and not unexpected, and b*gger all in the context of the life of the earth. Have we ALL lost our marbles?
Suffice it to say, it’s unlikely that we’re all going to 1). drown, 2). fry or 3). freeze in the immediate future (although the latter seems to be the current thinking). The only thing that’s going to kill us or destroy our way of life in the foreseeable future, is governmental meddling in the arrogant (and mistaken) belief that they’re going to change the climate by depriving us of comfort and cash.
Anyone hoping for the Gore effect at the Copenhagen conference might be cheered by the winter forecast here:
http://www.netweather.tv/index.cgi?action=longrange;sess=
3 millimeters is equal to 0.1181102 inches. I know that’s twice as long as Al Gore’s winkie, but even if the 3mm rise is true, it ain’t a whole heckuvalot.
But what about the midges??
Quakers ~= Lions!
Warwick Hughes has a post about the accuracy of Australian government sea level figures. Pretty interesting….betcha can’t guess what the trend shows!
How reliable are Australian Govt claims about rising sea levels ?
http://www.warwickhughes.com/blog/?p=283
There was much resistance to the theory of plate tectonics when it was first proposed. Now it’s accepted. Taking the theory one step farther, isn’t it reasonable to assume that the Earth’s crust moves in three dimensions?
Tectonic plates are not only moving relative to each other, they must also be moving up and down, like a flat piece of styrofoam bobbing on the waves in the ocean. As one side moves up, the other side moves down. On land, this would imitate changes in sea level.
This ‘study’ obviously got published because it made the obligatory reference to global warming. And it’s too bad the authors didn’t check out John Daly’s tide elevation marker in the Tasman sea. It would have saved them a lot of typing.
hmmmm…ground subsidence along coastal areas has been around a long time. Houston (Texas) recognized this decades ago, and attributes part of the subsidence to groundwater pumping – wells for drinking water. The State of Texas created the Houston-Galveston Subsidence District to limit the amount of water withdrawn from wells. That reduced but did not stop the subsidence.
http://geology.com/news/2007/01/subsidence-houston-is-sinking.html
Where is the peer review process for anything to do with promoting AGW?
The link to Texas Gulf Coast subsidence is very interesting reading – attributing coastal subsidence to tectonic forces that created the Gulf of Mexico when continents drifted apart.
http://www.mysanantonio.com/news/MYSA012107_01B_Sinking-Texas_1a6292b_html7818.html
Apparently, the authors do not believe the Gulf of Mexico was created by two large asteroids smacking into the earth, side-by side. (I don’t either, but I’ve read about this theory).
Please correct your citation. It’s from Penn – the University of Pennsylvania in Philadelphia. Not Penn State. Bad enough that we Penn State alums have to live with the embarrassment of having Michael Mann on the faculty.
[Done, thanx. ~dbs, mod.]
Can someone please explain to me how sediment analysis is more accurate than a tidal guage???
It would be nice to have more than 15-16 years of UC data. While that shows the recent short-term is clearly stable, you KNOW “they” are going to say that doesn’t represent what happened for the 20th century.
I’m on my side quite sure the peer-reviewing process went allright. The best attitude one should have here is to actually see how the authors estimated the sea levels, not to go randomly picking some graph on the internet, right? We don’t know much about these time series that are shown here… I mean: how representative of the coast are the two selected examples? Do they include corrections such as inverse barometer corrections? etc, etc.
I would really advise the original poster here to actually read the article in Geology to get things clear. From the abstract, it appears that they are using reconstructions to estimate the sea level rise before the 19th century and after that compare their reconstruction with tide gauges. Alas, I personally don’t have access to the full paper, so can somebody do the rest of the job here?
Salt marshes as proxies? Well, with U of Penn joining Penn State in this methodology, perhaps we should add a new nickname for the state of Pennsylvania — the Proxy State.
I suspect that at one time such studies would have been about coastal subsidence, rather than about sea level rise.
@Gabe. You’re lucky to be alive after sailing around Hatteras. Just kidding, but that area is not known as the “graveyard of the Atlantic” for nothing. Your understanding of the forces at play there is remarkable in one apparently exposed to the conditions for a short time.
The Outer Banks are indeed on the move at all times, generally southward. The inlets along the Banks are certainly not where they were when Sir Walter Raleigh established a colony on Roanoke Island in 1585, and are now kept open by continuous dredging.
An interesting experiment would be to get a phone book covering Mann’s Harbor, Manteo and Wanchese and call any listing for a male named Mann or Gray and ask him about what happens to the bottom topography of the sounds and coastal waters after a three-day Nor’easter. You could also ask him if his property is smaller than when his great grandfather owned it. His family will probably have lived in the area for 300 years and he will have a clue about sea level as well.
It’s possible the boys from Penn just wanted to go to the beach on the taxpayers’ dimes. The largemouth fishing where they drilled in Albemarle Sound is pretty good too.
I found a visual record of the peer review process here, hunter:
As one who has spent many very pleasant vacations on the Outer Banks for over 20 years (yikes! an equivalent of 6 cm sea level rise! 🙂 ) , I can attest that the development of the shore line there has been enormous. Where once there were isolated communites, it is now wall-to-wall houses from Corolla to South Nags Head. I really don’t have any idea of how much this would add to land subsidence. What is obvious is how the Banks move. Just look at the reason the Hatteras Light House had to be moved.
My daughters are already clamoring for us to make our reservation for an ocean front house for next year, and I plan on doing so for quite a number of years to come barring a hurricane opening up a new inlet; an event with a much higher probability than a 3 mm/year sea level rise.
Most of the coastal areas of the world are sinking. The exception are the areas that are still recovering from the last Ice Age. What does this have to do with Global Warming except we once had an Ice Age, now we don’t? Was the global warming that got us out of the ice age man made too? If not there just may be natural forces at work causing climate change even now. Inquiring minds want to know.
My family and i went to the outer banks back in June this year.Now i enjoy history and hearing and reading about the Wright Bro. flight .While there we listend to a speech that the tour guide gave at the Wright Bro. National Memorial ,which if you ever get a chance to go to is very informative.The gentleman had a photo which showed the first flight by powered plane.The tour guide pointed out to the audience that water was once next to where the flights took off.Now living in N C ,all of my life,i’ve heard about how the waters were rising along the outer banks but when we were outside of the National Memorial,which has actual marking of first, second and third flightthat took place on December 17th 1903, i noticed the water is roughly a half mile away which tells me that the waters were higher back then than they are today .
As a North Carolina resident, I say “Bull Honkey”!
Look at the layout of the state. It sticks out. Why does it stick out? Look at the Gulf Stream. The Outer Banks, as they are called, is entirely formed by the Gulf Stream. As such, the sands are always shifting. Cape Hatteras lighthouse was moved for this very reason. About 2 month ago, I vacationed on the beach and went to a town called Southport (beautiful town) and took a ferry a place called Fort Fisher, just south of Wilmington. Fort Fisher was the coastal area the Confederate army held during the Civil War. There still exists a sand fort the Confederate army built to withstand Union cannon fire. Once the Confederate army lost Fort Fisher, the war was over. But, due to the shifting sand, the fort is no longer by the ocean.
The dynamics of the North Carolina beach depends on the Gulf Stream, north-easterlies, and hurricanes, of which there are many of the last two. The sand is always rising and falling based on what nature deposits. The last hurricane to hit the Outer Banks broke one of the barrier islands in two. I went to Cape Hatteras in the spring and the state had to close one lane of traffic on highway 12 because the other lane was covered in sand. The sand and ocean in this area is very dynamic.
Only a person who has never been there can make such a study. How many trips to this area did those who did this study make? And for how many years? Since they are an “international” team, I bet, at most, one trip and most likely no trips. They probably just punched some numbers into their model and didn’t even think about WHY the Outer Banks have the shape it has. This study makes me think these guys are book smart but real-world dumb. There is a difference between knowledge and wisdom; they have knowledge but not wisdom.
Damn good sleuth work, Anthony.
And….
rcrejects (01:24:51) :
“And do we know what is happening with local subsidence?
In Australia, the sites showing greatest sea level rise are those where it is known that subsidence has occurred. eg Newcastle, Adelaide and Fremantle.
Of course, one could ask whether CSIRO (the providers of the data) and the MSM report this. You can guess the answer.”
Roger Sowell (05:19:33) :
hmmmm…ground subsidence along coastal areas has been around a long time.
Jimmy Haigh (02:32:42) :
There are many factors governing sea level. Some not mentioned here include rate of subsidence and coastal erosion or redeposition. From a quick look at the geography of the Carolinas it is clear that there is a lot of coastal erosion/ redeposition going on and as such it is hardly the best place to figure out what global sea level is doing.
Bingo, bingo, and bingo!
And if perchance you hear a sister report coming out of the “accelerating” rises across the rather heavily populated Chesapeake Bay, just to this region’s north, what you will NOT hear is a special type of subsidence there.
You see, it sits atop one of the largest impact craters in the world, 50 miles across and over a mile deep, from an asteroid impact 35 million years ago.
A little bit of subsidence here and there on the squishy, silty coastal plain.
Oh, but asteroids are not funded, so they must not exist.
Chris
Norfolk, VA, USA
The disingenuousness of the [University of Pennsylvania] press release about this study is truly mind boggling.
The headline says, “North Carolina Sea Levels Rising Three Times Faster Than in Previous 500 Years, Penn Study Says.” An assertion that is false because the satellite altimetry data show that sea level has not been rising in the area of the study since at least 1994.
Well, the main body of the press release actually says that the research found, “20th-century sea-level rise to be three times higher than the rate of sea-level rise during the last 500 years.” Well… Duhhh! Sea level wasn’t rising at all for most of the 500 years before the 20th century because most of those 500 years were in the Little Ice Age…
Sea Level Since 1700
Then the article says that the “jump appears to occur between 1879 and 1915.” Which is exactly the period in which sea level started to rise at the end of The Little Ice Age. If we zoom in on the 20th century, we can clearly see that global sea level did rise about three times as fast after 1915 as it did before 1915…
Sea Level Since 1900