Eric Worrall writes of a new paper trying to blame sea level rise on The Industrial Revolution, which started about 150 years ago:
The Australian National University has published a startling claim that sea level change has been more or less steady for the last 6000 years – until 150 years ago, when the sea started rising more rapidly.
According to the Abstract:
“Several areas of earth science require knowledge of the fluctuations in sea level and ice volume through glacial cycles. These include understanding past ice sheets and providing boundary conditions for paleoclimate models, calibrating marine-sediment isotopic records, and providing the background signal for evaluating anthropogenic contributions to sea level. From ∼1,000 observations of sea level, allowing for isostatic and tectonic contributions, we have quantified the rise and fall in global ocean and ice volumes for the past 35,000 years. Of particular note is that during the ∼6,000 y up to the start of the recent rise ∼100−150 y ago, there is no evidence for global oscillations in sea level on time scales exceeding ∼200 y duration or 15−20 cm amplitude.”
The abstract is at: http://www.pnas.org/content/early/2014/10/08/1411762111
The abstract notes that on longer timescales, SLR up to at least 40mm / year has been observed – so in this context “a few” mm per year does not seem particularly alarming, and is well within the range of natural variation. The fluctuation claim – the claim that sea level change in the last 150 years is faster than any change over the last 6000 years – is very much dependent on accurate dating of each of the proxy series. As we saw with the Hockey Stick controversies, any uncertainty about dating proxies tends to impose a strong hidden averaging effect on the data series, smoothing away peaks and troughs.
In any case, in many locations the current rate of change in sea level is swamped by local geological changes – one of the reasons changes in sea level are so difficult to calculate, is the land in many locations rises or falls faster than the alleged change in sea level.
Anthony adds:
But, other science suggests even higher sea levels during interglacials.
A paper published April 17th 2014 in Nature reconstructs sea levels over the past 5.3 million years and shows that sea levels were higher than the present during almost every interglacial period over the past 5.3 million years. Sea levels at present during the current interglacial are indicated as the added red horizontal line at zero meters on Fig. 2 below, and excursions above this line indicate sea levels during past interglacials as much as 50+ meters [164+ feet] higher than present sea levels. Thus, there is no evidence that sea level rise during the present interglacial is unprecedented, unnatural, unusual or any different from that which occurred in prior interglacials, or any evidence of influence by man on sea levels.
E. J. Rohling, G. L. Foster, K. M. Grant, G. Marino, A. P. Roberts, M. E. Tamisiea, F. Williams. Sea-level and deep-sea-temperature variability over the past 5.3 million years. Nature, 2014; DOI: 10.1038/nature13230
Fig. 2 with added red horizontal lines show present sea levels. Horizontal axis is thousands of years before the present.
The last interglacial ~100,000 years ago [Eemian] had sea levels between 16-31 feet higher than the present, although it appears as a tiny blip above the red line in the above graph with a much more compressed scale, but is better appreciated by this graph from another recent paper:
Sea levels during the last interglacial ~120,000 years ago were up to 5 meters higher than the present in this location and up to 9.5 meters higher at other locations (h/t to The Hockey Shtick)
So, if we had sea levels of 16-31 feet higher than the present 100,000 years ago, well before the dawn of the industrial revolution, what caused that? Inquiring minds want to know.
While climateers look for the bad in everything about our modern standard of living related to climate, this is worth noting:
In the words of Nobel Prize winning Robert E. Lucas, Jr.,
For the first time in history, the living standards of the masses of ordinary people have begun to undergo sustained growth. … Nothing remotely like this economic behavior has happened before.
Source: Landes, David S. (1969). The Unbound Prometheus: Technological Change and Industrial Development in Western Europe from 1750 to the Present. Cambridge, New York: Press Syndicate of the University of Cambridge. ISBN 0-521-09418-6.
UPDATE: Chip Knappenberger sends this graph along:
Note the tiny blip at the right, our present sea level rise.
The article says: “Of particular note is that during the ∼6,000 y up to the start of the recent rise ∼100−150 y ago, there is no evidence for global oscillations in sea level on time scales exceeding ∼200 y duration or 15−20 cm amplitude.”
Even the IPCC doesn’t think GHG’s perturbed climate much before 1950. If so, sea level rise from 1850-1950 was caused by the end of the LIA. However, sea level rise over 1850-1950 is believed to be about 10 cm (4 inches). So the authors are saying that their methodology is INCAPABLE of detecting important variations in climate – such as the end of the LIA – by their effect on sea level. Therefore, they are unlikely to be able to tell us about the existence of other events such as the MWP, the Roman Warm Period, etc. Likewise, the anthropogenic contribution to SLR – which is less than the 10 cm of SLR since 1950 – would also be undetectable.
It makes sense to be skeptical of any reports concerning sea level during the last interglacial. The Earth’s crust is resting on a viscous mantle than deforms under the weight of ice caps, mountain ranges and continents. The areas covered by ice caps subside (sink) during glacial periods and are still rebounding today. The ocean basins far from ice caps sink under the weight of the extra water present during interglacials. Ocean basins near ice caps rise because of the subsidence of nearby ice covered land. Even if we stay far away from the boundaries between tectonic plates, are any really any “geologically stable” locations on our viscous planet from which we can reliable measure sea level 100,000 years ago to within a few meters?
It can be very educational to look at a few maps. The center of Greenland is below sea level. The usual maps of Antarctica don’t show us where land rises above sea level today. They show the outline of the continent as it would look if the ice cap melted and the land rebounded!
http://en.wikipedia.org/wiki/Greenland_ice_sheet#mediaviewer/File:Topographic_map_of_Greenland_bedrock.jpg
http://commons.wikimedia.org/wiki/File:AntarcticBedrock2.jpg?uselang=en-gb
http://commons.wikimedia.org/wiki/Atlas_of_Antarctica?uselang=en-gb
The internet is such a pesky invention from Gore. Here is NASA living in Never Never Land.
Yet there is NO ACCELERATION in the rate of sea level rise! This is how you know you are being fooled.
Another boring study by ‘Grab a Grant’ Clim-astrologists who just like the charlatans of the 1930s re’d ‘Tea-Leaves’ and put forward their own Interpretation of what they saw.
So just to educate (new) readers to the complexity of ‘Sea Level’ measurement to the nearest Metre watch this short Video.
What is sea level?
Sea level is what we measure with a tidal gauge.
As long as the interglacial continues, sea level should continue rising. The glaciers on the southern third of Greenland are too far south for glaciers to exist. The solar energy in the summer is too strong. It just takes an interglacial lasting 15,000 years or more to melt this ice out.
There is probably something similar in Antarctica and all the mountain glaciers that have remnant influence from the last ice age . They will continue melting out, very slowly, until the interglacial comes to an end in 52,000 years. It just takes lots of time to melt out kms of ice.
I also note that 94 million years ago at the height of the Cretaceous, sea level was 265 metres higher than today and up to 40% of the continents were flooded with shallow ocean. That was because the newly forming Atlantic ocean was much less deep than it is now and the ocean had nowhere to go except onto the Land.
Bill, the Holocene has been a stepdown from early Holocene temperature highs. There is no treason to expect this multi-millenial trend to change, taking the long view.
As far as sea level is concerned, this will present a problem only in locales where subsidence is a problem.
IMO, thermal expansion from more active seafloor spreading, ie submarine volcanism at the ridges, as the continents moved apart also contributed to very high sea levels in the Cretaceous, especially its middle. Plus of course, no ice sheets.
The southern dome of the Greenland Ice Sheet apparently melted completely during the long, hot interglacial of MIS 11, c. 400,000 years ago. Same thing seems to have happened around 800,000 years ago. The Eemian may have been hot enough but didn’t last long enough for the whole dome to melt, but it did partially.
If the Holocene really does persist for another 52,000 years, then earth could indeed experience natural, not man-made, “catastrophic” global warming.
Milo,
Which is correct? The southern dome of the Greenland Ice Sheet apparently melted completely during the long, hot interglacial of MIS 11, c. 400,000 years ago.
or
Ice sheets have one particularly special property. They allow us to go back in time and to sample accumulation, air temperature and air chemistry from another time[1]. Ice core records allow us to generate Ice sheets have one particularly special property. They allow us to go back in time and to sample accumulation, air temperature and air chemistry from another time[1]. Ice core records allow us to generate continuous reconstructions of past climate, going back at least 800,000 years[2]. of past climate, going back at least 800,000 years[2].
How do they get ‘continuous reconstructions’ of 800,000 years if the dome melted 400,000 years ago?
Glaciers in Greenland have been advancing since the Holocene optimum, as shown by many studies. It reached a minimum about 4-5,000 ago and have been mostly growing since then. This includes southern Greenland, see here for example:
http://www.geus.dk/publications/bull/nr27/nr27_p1-68.pdf
http://www.geus.dk/publications/bull/nr14/nr14_p01-78_A1b.pdf
And there are few mountain glaciers that have “remnant influence from the ice age”. Most are neoglacial, i. e. less than 10,000 years old.
I have lived in San Diego for 20 years. I have friends who have lived on the beach nearly 40 years. The water has [now] risen enough for them to notice any rise. Any rise has been of an inch or less. Yet San Diego is not spending tax dollars to study what to do about the ocean rise caused by climate change. It drives me nuts.
I have been visiting the same exact spot on the northern Oregon coast since 1962. In that time, sea level change has not required any humans to do anything, period. ZERO. That is 1/3 of Worrall’s 150 year time period. Zero adaptation necessary. I guess it is still OK to take measured, high frequency, high resolution data and tack it on to low resolution proxy estimates. Mann must be proud.
Since 1950, I’ve experienced no change at Seaside, where my grandfather’s company built the Turnaround & seawall in the 1920s. In fact, the tide surges were higher when I was a kid than now. Anecdotal, I know. Didn’t check the local tide gauge data.
change not to now in my post
Ephesus was established as a sea port about 400 BC. It is now miles from the ocean.
The citadel at Rye, England was built in 1249 on the English channel. It is now over a [mile] from the channel.
Make that more than a mile from the English channel.
Australians again. In an earlier thread today, I made the following observation:
http://wattsupwiththat.com/2014/10/13/another-major-misunderstood-climate-issue-models-underplay-plant-co2-absorption/
“Gary Pearse
October 14, 2014 at 7:17 am
Also, an interesting phenomenon in the life cycle of climate science is emerging. More and more papers are coming out eschewing the alarm and fewer and fewer alarmist papers are coming out (All in Australia? as they battle their defunding – which ironically underscores the political science that it had become). I wondered how this CAGW would all end. It will (be) like covering a linoleum floor with a new layer of linoleum.”
also, the plummy statement in the abstract above of this thread:
“..allowing for isostatic and tectonic contributions, we have quantified the rise and fall in global ocean and ice volumes for the past 35,000 years.”
How did they allow for these contributions? Who did their calculations? Tossing off a complex questions like these with a ho hum pretty well pigeon holes this paper.
Change NOW to NOT is more the norm. John Coleman;
Now I can get on with my grouse.
I want to take issue with Sea Level Guages as a means of measuring sea level based on what we call Isostatic Rebound. Isostatic Rebound is the rising of the landmass due to the absence of the Ice Burden from the last Ice age.SO we install a Sea Level Guage on a Dock or Jetty which is fixed to the landmass and we take occasional readings of the sea level over a prolonged period and expect to get a reliable reading. . Does anyone see anything wrong with that?
Isostatic Rebound is fiction it does not occur. What happens is that the sea is receding and the land mass appears to rise. We all accept sea level as a fixed datum. Rather than admit that sea levels are receding we opt for another fallacy which is, that sea level is rising. So we keep digging ourselves deeper and deeper into the realm of mythology while the facts are staring us in the face.
It is time we debunk the Post Glacial Rebound Theory and the Ice age on which we are fixated. Its all wrong and we are doing science a great injustice because all these theories were first proposed by Charlatans. Richard Guy
Richard,
I see now that you are indeed serious. What do you suppose made all the observed glacier & ice sheet-caused features upon the earth’s surface if not glaciers & ice sheets? Those who first correctly interpreted these features were not charlatans, like today’s CACA advocates, but among the greatest scientists ever to have lived & worked.
Having shown you that your fantasy about Agassiz & Darwin is pure paranoid delusion born of ignorance, I’d like further to awaken you to the reality of ice ages in the history of our planet.
Post-glacial rebound is not “just a theory”. It’s an observable, measurable fact. Just as is the fact that Hudson’s Bay exists because land is lower there due to the weight of the ice sheet which depressed the area.
GEOPHYSICAL RESEARCH LETTERS, VOL. 27, NO. 23, PAGES 3925-3928, DECEMBER 1, 2000
Measuring Postglacial Rebound with GPS and Absolute Gravity
Kristine M. Larson
Department of Aerospace Engineering Sciences, University of Colorado, Boulder
Tonie van Dam
European Center for Geodynamics and Seismology, Luxembourg
Abstract. We compare vertical rates of deformation derived from continuous Global Positioning System (GPS) observations and episodic measurements of absolute gravity. We concentrate on 4 sites in a region of North America experiencing postglacial rebound. The rates of uplift from gravity and GPS agree within one standard deviation for all sites. The GPS vertical deformation rates are significantly more precise than the gravity rates, primarily because of
the denser temporal spacing provided by continuous GPS tracking. We conclude that continuous GPS observations are more cost efficient and provide more precise estimates of vertical deformation rates than campaign style gravity observations where systematic errors are difficult to quantify.
You’re welcome.
I thoroughly agree with milodonharlani. Having grown up literally on the Younger Dryas ice-marginal zone in Scandinavia I know this country has been covered by ice not so long ago. I can see it.
I remember well the first time I visited a major ice-cap (Vatnajökull) and saw for myself all those glacial landforms I know so well actually being created today: sandur fields, marginal deltas, end moraines, ice contacts, ice-dammed lakes, bottom moraine, subglacial rivers….
Don’t try convincing me that the ice-age didn’t happen.
Jerry Henson thanks for mentioning that the Citadel at Rye and Ephesus are now miles from the sea. Sandwich Peterborough and Camber all follow the same pattern Miles from the sea. All the ancient castles and forts in Wales are miles from the sea on which they were original built. All the Roman Roads in Wales which were originally built on the sea are now far inland. The Abbey San Michel on the Normandy Coast of France built six miles out in the English Channel 1000 years ago is now part of the French Mainland. The Castle San Michel Mount at Penzance on the southern tip of Britain was once two miles out from Penzance but now is part of the coastline. All the ancient cities on the Mediterranean are now six miles inland as well as all the old ports on the coast of Italy all six miles inland. Do you begin to see a worldwide pattern???
The State of New Jersey has been selling off the foreshore Atlantic City for millions as soon as the sea retreats and leaves the land behind. They have discovered the receding sea phenomenon purely by accident. They have been using aerial surveys since 1922 and became aware of the growth of the foreshore and the departure of the sea. So the foreshore lands have built the Trump and Playboy hotels. Read my Book “The Mysterious Receding Sea” and see my Vdeos on YOutube. Richard Guy 867-445-8012
Richard Guy
As the sea level varies locally as gravity varies, does anyone know what the weakening of the gravitational field for the last 200 years done to sea level?
OK, a WAG. Less gravity means more air molecules escaping to space, lowering air pressure, causing sea level rise.
Crazy maybe, but just off the top of my head.
Whatever makes you think the gravitational field has weakened?
The sea level in Kakadu National Park used to reach the top of the Arnhem Escarpment, between 400/600 feet where many of the Aboriginal residential and art gallery caves can still be found..
Now Kakadu is mainly floodplain at sea level with the Escarpment a sharp reminder of where the seas once reached.
Perhaps the IPCC can explain?
Sea level was higher during the Cretaceous Period, 144 to 65 million years ago. When the first humans came to Australia c. 60,000 years ago, it was a lot lower than now, thanks to all the water locked up in continental ice sheets.
If it was a lot lower does it follow the Aborigines were living 400 feet above sea level (or even underwater) and how did they reach their caves as , to my knowledge, no traces of 400 feet ladders or steps have been discovered
They either walked or climbed up from below or came down from above. No ladders required. Not that they couldn’t have made ladders. There is no mystery. Please visit the pueblos of the American SW sometime.
They climbed up through 400 feet of water?
There were not 400 feet of water there when people arrived in Australia.
People do live away from the shore you know, Escarpments do not indicate former coastlines. I presume you are from Australia, so you shold have heard of the Great Escarpment, The Illawarra Range and the Darling Range. They are all escarpments, but not old coastlines.
Since 1880 in Sydney harbor the sea level has been rising 0.65 mm/per year, although my friends think otherwise.
http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=680-140
As the planet heats up, the oceans rise…wheeee!!
http://www.slate.com/blogs/future_tense/2014/10/13/nasa_earth_just_experienced_the_warmest_six_month_stretch_ever.html?wpsrc=fol_tw
Recent research shows the current warm stretch is probably the planet’s warmest in at least 4,000 years. That means global temperatures may have already passed a level that human civilization has never experienced. The sheer size and depth of the world’s oceans means that most of global warming’s extra heat has been stored there. For the last decade or so, atmospheric warming has been playing catch up.
http://www.theguardian.com/environment/2014/oct/14/sea-level-rise-unmatched-6000-years-global-warming
This is arrant nonsense.
For at least 150 years during the Medieval Warm Period, earth was warmer than during any 50 year period of the Modern WP to date.
But the Roman WP was warmer than the Medieval & the Minoan WP was warmer than the Roman. And the Holocene Climatic Optimum was warmer than the Minoan. And the Eemian Interglacial was hotter than any part of the Holocene.
CACA is a crock.
Just who kept the records 4000 years ago and have the y been subjected to “peer review”?
The egyptians did. They recorded the effect of the 4.2 KA event, a major drying and cooling interval c. 4200 years ago, which caused the Yang Shao culture, the Indus culture, the Akkadian civilization, the Eblaite culture and the Egyptian Old Empire to collapse. Egypt finally recovered after a 200-year dark age, which is why we do have records about it. They’re not peer-reviewed though.
Martin,
There has been no acceleration in the rate of sea level rise. There is evidence of a deceleration.
http://www.nature.com/nclimate/journal/v4/n5/carousel/nclimate2159-f1.jpg
http://www.nature.com/nclimate/journal/v4/n5/carousel/nclimate2159-f2.jpg
Martin
October 14, 2014 at 8:00 pm
” The sheer size and depth of the world’s oceans means that most of global warming’s extra heat has been stored there.” [Guardian]
Every day we learn a bit more about the inner workings of the journalist brain.
When referring to the issue of sea-level rise, I prefer to rely on the evidence of Dr Nils Axel Morner, one of the world’s greatest ever experts on sea-level. His extensive research into the matter revealed no discernible rise in sea-level that is of any risk to the planet.
Sea-level rise is not a problem now or in the foreseeable future. It’s simply being used by propagandists to promote alarm about climate change in the hope that governments will sign an international agreement on fossil fuel energy use.
Yeah, that is why the >100 year old tidal gauges in Australia show no change.
Climate creeps are annoying deceivers.
“Of particular note is that during the ∼6,000 y up to the start of the recent rise ∼100−150 y ago, there is no evidence for global oscillations in sea level on time scales exceeding ∼200 y duration or 15−20 cm amplitude.”
Yeah because 130 years ago we started using tide gauges. Isn’t it curious when we shifted from geologic proxies to tide gauges, sea level rise accelerated? Familiar hockey stick from tree rings to thermometers.
As I type I can look out my window and see the harbour, It was built 150 years ago. Looking at the harbour wall I can’t see any evidence that the quay sides have been raised to accommodate any sea level rise. Interesting history for this harbour, Milford Haven, originally built to take the Trans-Atlantic ocean liner trade. Due to muddle and politics Liverpool got that trade and Milford had to make do with fishing.
History and some pictures here: http://www.llangibby.eclipse.co.uk/
The eye can be deceptive. Tide gauge data since 1987 for Milford Haven is available from PSMSL here: http://www.psmsl.org/data/obtaining/stations/1700.php
The trend in the monthly data from January 1988 to Oct 2014 is +7.4 mm/yr, which is slightly over twice the global MSL rise rate. (Filtering out Dec 1989, which is flagged as suspect, the rate rises to 7.8 mm/yr).
If that rate continues, sea levels will be about 2 feet above their current level in Milford Haven by 2100.
Sorry, should be October 2013, not 2014.
Google “sequence stratigraphy”.
http://www.john-daly.com/deadisle/ Go to this to see picture of sea level mark made in 1841 in Tasmania .
I would make two points:
1) Before we worry about “sea level” we should find out whether we need to worry about the high tide level. Has that changed anywhere? And would anyone be more concerned about that than the Dutch? (Many of whom live below sea level.) Are they in a state of national panic? I don’t think so.
2) The surface of the sea conforms to the geoid, which is a surface of constant gravitational potential. This surface is not spherical, has many complex harmonics, and may change over time as the gravitational field distribution of the Earth changes over time. Measurement of the gravitational field harmonics is still a data resource from satellite orbits.
The Dutch are not worried about “sea level.” I think the sea is worried about the Dutch. They literally drained part of the North Sea creating land the size of 14 cities of Paris. 400,000 Dutch now lives on what was once sea.
So tell us Michael; the apparent gravitational pull at any point on the earth surface, would seem to depend not only on the mass distribution around that point, but also on the rotational angular velocity at that location.
So which does the sea surface conform to ? Is equatorial ocean water sitting on a gravitational bulge, so that it tends to flow towards the pole, or is the whole thing in latitudinal equilibrium , so that it doesn’t tend to flow in any direction ?
Sea levels have never risen before which is why the existence of Doggerland must be dismissed as outright fantasy.
The difference between the geoid and ellipsoid is a very slowly-changing variable, dependent primarily (IIRC)on inhomogeneities in crustal density. Hawaii (the big island), for example, corresponds to a relatively drastic change in the geoid-to-ellipsoid height differential over a relatively small ground distance. Other rapid changes are observed near e.g. the Himalayas. But there could be other effects I am ignorant of.