GSA Annual Meeting Presentation: Could Estimates of the Rate of Future Sea-Level Rise Be Too Low?
Boulder, Colorado, USA – Sea levels are rising faster than expected from global warming, and University of Colorado geologist Bill Hay has a good idea why. The last official IPCC report in 2007 projected a global sea level rise between 0.2 and 0.5 meters by the year 2100. But current sea-level rise measurements meet or exceed the high end of that range and suggest a rise of one meter or more by the end of the century.
“What’s missing from the models used to forecast sea-level rise are critical feedbacks that speed everything up,” says Hay. He will be presenting some of these feedbacks in a talk on Sunday, 4 Nov., at the meeting of The Geological Society of America in Charlotte, North Carolina, USA.
One of those feedbacks involves Arctic sea ice, another the Greenland ice cap, and another soil moisture and groundwater mining.
“There is an Arctic sea ice connection,” says Hay, despite the fact that melting sea ice — which is already in the ocean — does not itself raise sea level. Instead, it plays a role in the overall warming of the Arctic, which leads to ice losses in nearby Greenland and northern Canada. When sea ice melts, Hay explains, there is an oceanographic effect of releasing more fresh water from the Arctic, which is then replaced by inflows of brinier, warmer water from the south.
“So it’s a big heat pump that brings heat to the Arctic,” says Hay. “That’s not in any of the models.” That warmer water pushes the Arctic toward more ice-free waters, which absorb sunlight rather than reflect it back into space like sea ice does. The more open water there is, the more heat is trapped in the Arctic waters, and the warmer things can get.
Then there are those gigantic stores of ice in Greenland and Antarctica. During the last interglacial period, sea level rose 10 meters due to the melting of all that ice — without any help from humans. New data suggests that the sea-level rise in the oceans took place over a few centuries, according to Hay.
“You can lose most of the Greenland ice cap in a few hundred years, not thousands, just under natural conditions,” says Hay. “There’s no telling how fast it can go with this spike of carbon dioxide we are adding to the atmosphere.”
This possibility was brought home this last summer as Greenland underwent a stunning, record-setting melt. The ice streams, lubricated by water at their base, are speeding up.
Hay notes, “Ten years ago we didn’t know much about water under the Antarctic ice cap.” But it is there, and it allows the ice to move — in some places even uphill due to the weight of the ice above it.
“It’s being squeezed like toothpaste out of a tube,” explains Hay. The one thing that’s holding all that ice back from emptying into the sea is the grounded ice shelves acting like plugs on bottles at the ends of the coastal glaciers. “Nobody has any idea how fast that ice will flow into the oceans once the ice shelves are gone.”
Another missing feedback is the groundwater being mined all over the world to mitigate droughts. That water is ultimately added to the oceans (a recent visualization of this effect in the U.S. was posted by NASA’s Earth Observatory: http://earthobservatory.nasa.gov/IOTD/view.php?id=79228).
All of these are positive feedbacks speeding up the changes in climate and sea-level rise.
“You would expect negative feedbacks to creep in at some point,” says Hay. “But in climate change, every feedback seems to go positive.” The reason is that Earth’s climate seems to have certain stable states. Between those states things are unstable and can change quickly. “Under human prodding, the system wants to go into a new climate state.”
WHAT: Could Estimates of the Rate of Future Sea-Level Rise Be Too Low?
WHEN: Sunday, 4-November, 9:15–9:30 a.m.
WHERE: Charlotte Convention Center, Room 219AB
ABSTRACT: https://gsa.confex.com/gsa/2012AM/finalprogram/abstract_209198.htm
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Dr. Hay may find this upcoming NASA JPL project problematic with his claims:
Finally: JPL intends to get a GRASP on accurate sea level and ice measurements
“But in climate change, every feedback seems to go positive.”
Classical alarmist drivel.
Ten years ago, the Alarmists warned that the Northern Hemisphere would soon be snow free.Seven years ago the Alarmists focused on tropical storms. When they failed to materialize it was the melting polar ice caps. When the north pole refused to go ice free, sea levels the Alarmists now focus on sea levels…. and on, and on it goes.
Gary Pearse said
“I think studies of “sea level rise” at atoll islands would be an excellent measure of the health of the coral.”
There are quite a few atolls near the Marhsall Islands. From what I can tell, those atolls are still there.
daveburton says:
November 2, 2012 at 9:52 am
http://www.sealevel.info/
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Thanks Dave and great website. Some of us have been looking for this data (and especially the averages) for quite awhile now and short of downloading all the different gauges one at a time, it didn’t seem possible before. So, thanks again.
Any chance the data can be consolidated/displayed over time – the acceleration question in the 1990s/2000s is still an open question.
It seems that you have the data in order to put this myth to the test. Clearly the satellite data is going to be redone now but sea level acceleration is a “Huge” issue in the global warming debate.
I don’t see hardly any science in this it is just made up assumptions that can’t be backed up by any observations. The AMO is part of the mechanism that brings heat to the Arctic circle and this comes from warmer water to the South where the sun heats it. The sun has very little effect in the Arctic circle above 75N. The difference between cooling and warming is about 200w/m2 therefore most of the Arctic circle only reaches above this value for a very short time during the year. Open water in the Arctic circle for majority of the time is a huge energy loss.
1) The assumption that sea levels rising faster than the model predicted – wrong.
2) The assumption about feedback – wrong, impossible with the water cycle.
3) The assumption of the amount of sea level rise observations – wrong, show lower rises (even these have been exaggerated).
“Then there are those gigantic stores of ice in Greenland and Antarctica. During the last interglacial period, sea level rose 10 meters due to the melting of all that ice — without any help from humans. New data suggests that the sea-level rise in the oceans took place over a few centuries, according to Hay.”
It gets worse, no the ice cores did not all melt. How did an ice core from Antarctica dating back about 800,000 years occur? How did an ice core from Greenland going back over 400,000 years occur? Quite a bit of Greenland ice melted, but still can extract ice cores going back to the last few interglacial.
“Hay notes, “Ten years ago we didn’t know much about water under the Antarctic ice cap.””
10 years ago you knew even less about climate and this extract gives an assumption of errors that show a lot of research by you is still needed.
I think I figured out how he fudged the number. I looked at the colorado data and, of course, got about 3mm per year. Taking from 2006 to the present you get about 2mm per year. BUT, if you take from 2011 to the present you can get about 9mm per year! That is probably how he got the 1 meter number. Just torture the data till it confesses.
I have to confess I’m really puzzled by all the claims of massive and accelerating sea level rise. I’ve just come back from a holiday in Bude (Cornwall, SW England), where my mother’s parents used to live. I’ve been visiting this particular area regularly for nearly 5 decades – admittedly I don’t remember the first few years, but my father has photographic evidence.
The beaches do change a little, the amount of sand varies (sometimes the rocks – very nice example of flysch sedimentation, incidentally – are more visible, sometimes almost buried), the river running down one of the beaches may be in fairly defined channels or spreading itself in a not quite monomolecular layer across virtually the whole beach, the stony area at the top of some of the beaches changes its extent, more bits of cliff occasionally fall off, and so on and so forth.
But over the whole of the nearly 5 decades, I can’t say that there is any perceptible change in the sea level whatsoever. The tide seems to come in no further or higher than it used to according to the sea canal lock gates (installed 1835, refurbished in 2000) or the steps down to the sea pool (1930); the breakwater (1843) hasn’t needed to be built up further; the channel markers up to the harbour (contemporaneous with the breakwater) are still the same; the beach huts along the sea front are still there …. I could go on, but I’m just rambling now 😉 The point I have is that I’m not denying that sea level is rising, I’m just saying that I don’t believe it can have been more than a few millimetres in 180 years around that bit of North Cornwall.
During the last interglacial period, sea level rose 10 meters due to the melting of all that ice.
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And if the polar sea floor is still rising, then surely it will be raising sea levels in areas that have no glacial-rebound – areas like Florida.
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I don’t know if anyone has brought this up yet.
http://www.foxnews.com/scitech/2011/06/17/research-center-under-fire-for-adjusted-sea-level-data/
Pretty soon, there will be no Bikini Atoll.
Don K, moving a road or such is trivial compared to building 4,000 wind turbines, or any of the other vast nonsense going on in the name of reducing global warming.
Gunga Din says:
November 2, 2012 at 12:57 pm
It is just made up nonsense about the volume of ocean water and extremely biased. Why don’t they take into account the flowing lava and expanding basalt rock under the ocean with an expanding planet as the Earth cools? This leads to a gain in ocean rises that to correct would have to lower the sea levels. All this is irrelevant as it is what the actual rise is compared to the physical previous sea level, not an imaginary level.
The Legacy Media once again portray a “model” (are alorithms with purposely built in errors even properly called models?) as a result. Scientific snake oil salemen need to be punished. Since they are now crossing the line and getting lawyahs involved, well heck, two can tango.
It looks like the rats are still clambering onto the ship rather than leaving it.
climatereason – You can do your Australian coral reef research in warm sunshine without getting your feet wet – http://www.kimberley-tours.com/images2/sunset-windjana.jpg – just stand on dry land and look up. The highest point of the reef is about 200m above sea level.
Not even read the article, nor the comments but…
Que? I live on the coast, I’ve seen no perceptible sea level rise!
Rant over, now I’ll read it.
DaveE.
I wish a WUWTer would get to the bottom of this question, which I pose toward the end of the material below, namely is the U. of Colo. GIA redefinition of sea level generally accepted by other labs studying the matter or not?
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13 months ago there was a controversy about this readjustment. Here is a link to an article about it:
http://www.foxnews.com/scitech/2011/06/17/research-center-under-fire-for-adjusted-sea-level-data/
A quote from the article said:
To which I responded:
A WUWT thread a month earlier, with some good comments, can be found here:
http://wattsupwiththat.com/2011/05/05/new-sea-level-page-from-university-of-colorado-now-up/
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One objection I have to this readjustment is that it unjustifiably and misleadingly redefined “sea level” for propagandistic purposes (as my jibe above implied). Here are the standard definitions of “sea level”:
Mean sea level (MSL) is a measure of the average height of the ocean’s surface (such as the halfway point between the mean high tide and the mean low tide); used as a standard in reckoning land elevation.[1]
http://en.wikipedia.org/wiki/Sea_level
“Sea level, average height of the ocean” [NB, “height,” not “volume.”]
http://en.wikipedia.org/wiki/Sea_level_(disambiguation)
(My dictionaries define sea level similarly.)
From:
The boldfaced portion above implies that the sea level changes as the ocean floors sink or rise. Steve Nerem’s interpretation is that the sea level should remain constant as the ocean floors sink or rise, by applying a correction factor to ensure that it does so on paper, regardless of what’s happening in the real world, and in defiance of what the conventions in his field prescribe.
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A few months ago I visited the U. Colo. site. I read some of their material, which I’ve posted below. I was amazed at this sentence in their last paragraph. “this [GIA] correction is now scientifically well-understood and is applied to GMSL estimates by nearly all research groups around the world.” Is it really true, or are they being disingenuous? I.e., do the other research groups “apply” it, but not call the result “sea level”? (Or have they all recently acted in concert to support the warmist narrative?) This question deserves critical attention from WUWTers, and a thread devoted to the topic titled “On the Level?” First, here are some links:
Home page:
http://sealevel.colorado.edu/
raw data (with GIA correction):
http://sealevel.colorado.edu/files/2011_rel4/sl_ns_global.txt
chart with GIA correction
http://sealevel.colorado.edu/files/2011_rel4/sl_ns_global.eps
Under “Similar plots” there is only a chart and data set for “Seasonal signals Retained.” There’s nothing showing one with GIA correction removed.
Chart through July without GIA (from WUWT, not available from UC itself via home page)
http://climate4you.com/images/UnivColorado%20MeanSeaLevelSince1992%20With1yrRunningAverage.gif
Gary Lance says “The year 2100 is a long way off and there is the potential for the sea level to rise enough that cities like NYC and DC will have to be abandoned. ”
Gary, please look at an atlas with topography. Then maybe study the Fox Point storm barrier in Providence RI (cost $16M in the early 60’s). The worst case I can think of is some parts of northern NJ will have to be abandoned when NYC puts up a high storm barrier causing storm surges to be directed into unprotected parts of NJ. As for DC, your claim is pure piffle. The only reason the storm barrier isn’t done yet is pure incompetence and that is only needed for a small part of DC.
Roger Knights says:
November 2, 2012 at 3:06 pm
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All that stuff justifying GIA sea level adjustments sort of reminds me of comments I’ve seen on WUWT justifying Hansen’s failed predictions and Mann’s Hockey Stick.
eric1skeptic says:
November 2, 2012 at 4:25 pm
Gary Lance says “The year 2100 is a long way off and there is the potential for the sea level to rise enough that cities like NYC and DC will have to be abandoned. ”
Gary, please look at an atlas with topography. Then maybe study the Fox Point storm barrier in Providence RI (cost $16M in the early 60′s). The worst case I can think of is some parts of northern NJ will have to be abandoned when NYC puts up a high storm barrier causing storm surges to be directed into unprotected parts of NJ. As for DC, your claim is pure piffle. The only reason the storm barrier isn’t done yet is pure incompetence and that is only needed for a small part of DC.
They’d have to build it out of Legos.
I’d give it three years before it really starts dawn on people that Greenland isn’t going to be around like they thought it would and the IPCC forecasts on sea level rise are as bad as their arctic sea ice predictions.
Gondo says:
November 2, 2012 at 7:17 am
“An unrelated issues is that much of the sea-level rise is happening at the open ocean where tide-gauges cannot be placed. I hope this clarifies things.”
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So, not much for us coastal-dwellers to worry about after all, then?
Don K says:
November 2, 2012 at 6:00 am
“. . . non-trivial.”
Given a bit of spare time, you might like to search using the terms ‘panga +cwu’ – one return is shown below but the main research is trying to understand the earthquakes generated by the Cascadia Subduction Zone.
http://www.geodesy.cwu.edu/realtime/
Also, see my somewhat jesting comment at 10:35 pm.
eric1skeptic says:
November 2, 2012 at 4:25 pm
Gary Lance says . . .
It’s not nice to mess with Mother Nature, in the case of Wash., D. C., she might wish to reclaim what was taken from her. See this:
http://www.theatlantic.com/technology/archive/2011/03/washington-dcs-19th-century-reclamation-project/73078/
Historic images!
Janets
further to your holiday in Bude.
I wrote this article last year
http://judithcurry.com/2011/07/12/historic-variations-in-sea-levels-part-1-from-the-holocene-to-romans/
Its worth looking at the ‘longer document’ referenced in the first few paragraphs. In this I look in great detail at St Michaels Mount, which for those who dont know the UK is on the opposite coast some 40 miles away. It is clear that the sea levels in Roman times were higher than today taking into account land changes
tonyb
Roger Knights says:
November 2, 2012 at 3:06 pm
…To which I responded:
Let’s say the ocean basins were shrinking. Would he have reduced the rate of sea level rise to compensate? To ask the question is to know the answer. …
Thanks for the post Roger. We have seen a continuous decrease of the sea level rise rate from 2007 on which continuously reduce the overall rate of the satellite era:
3.5 mm/year, 3.3 mm/year, 3.2 mm/year, 3.1 mm/year
Then instead of showing a decrease under 3.0 mm/year as it should have come, after a long break in the updates, the U of C came with the retroactively GIA adjustment to fit for the whole satellite era (a total adjustment of some 5 mm sea level rise) and raised back the rate to 3.2 mm/year.
Now going back to the actual 3.1 mm/year (which is the 2.8 mm/year that we see at NOAA)
http://ibis.grdl.noaa.gov/SAT/SeaLevelRise/LSA_SLR_timeseries_global.php
this is still more then the tide gauges shows.
Even the accepted about 16 cm of sea rise during the 20th century is concluded with some GIA adjustment and not on real measurements. So the accepted rise is not against the real shores but against some fictive computer generated shore .
This begs the question to re-analyse all the adjustments and calibration that have been repeatedly done to the satellite data.
The old models are flawed, as Bill Illis said above:
Bill Illis says:
November 2, 2012 at 5:09 am
janets says:
November 2, 2012 at 12:50 pm
“…But over the whole of the nearly 5 decades, I can’t say that there is any perceptible change in the sea level whatsoever. The tide seems to come in no further or higher than it used to according to the sea canal lock gates (installed 1835, refurbished in 2000) or the steps down to the sea pool (1930); the breakwater (1843) hasn’t needed to be built up further;…”
which is what the defunct John Daly also said referring the Island of Dead in Australia:
http://www.john-daly.com/ges/msl-rept.htm
the mark ” was put there in 1841 by the famous Antarctic explorer Captain Sir James Clark Ross and amateur meteorologist Thomas Lempriere to mark mean sea level.”
Reading now the post of Bill Hay I get a better understanding of the attitude at the U of C. I fear it looks like some theorists far away from the sea working too much with models and too little with real data.
His logic of the Arctic sea waters:
That warmer water pushes the Arctic toward more ice-free waters, which absorb sunlight rather than reflect it back into space like sea ice does. The more open water there is, the more heat is trapped in the Arctic waters, and the warmer things can get.
Make me question if he really did the calculation? The sentence as above cannot stand as is, what he misses is that clouds are the main albedo driver – 5 times more incoming solar energy reflected by clouds then what is reflected by the whole surface of the Earth, not the Arctic!
http://en.wikipedia.org/w/index.php?title=File:Breakdown_of_the_incoming_solar_energy.svg&page=1
that the albedo measurement tells a different story:
http://wattsupwiththat.com/2007/10/17/earths-albedo-tells-a-interesting-story/
and water reflectivity increases greatly with the angle:
http://en.wikipedia.org/wiki/File:Water_reflectivity.jpg
but the energy radiated to the sky does not decrease – therefore the Arctic ocean balance is negative at a certain angle of incidence for open waters and the result is ocean cooling in that case.
Yes natural climate change can be tremendous, fast and huge, much more that we have seen in our short written history. Yes in the eemian the sea levels were higher, but it was not due to atlanter from Atlantis driving their SUVs, or the neanderthaler burning coal to warm their caves, it was natural. And now there are other urgencies that we should focus on, and not fighting an odourless colourless gas – that at today’s concentrations is increasing the photosynthesis process and the biosphere – based on incomplete analyses and unconfirmed models.