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
“Dr. Hay may find this upcoming NASA JPL project problematic with his claims:”
CAGW alarmists quite often find science and the facts to be problematic with their claims.
Just an observation.
***
“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.”
***
Yeah, right. Most geologists have common sense…
“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 ”
No they don’t. This is a barefaced lie.
The TRF-error the new satellite mission is designed to minimize is 0.45mm/year, which almost an order of magnitude smaller than the sea-level signal. Doesn’t WUWT review what he posts?
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.
It’s refreshing to read some honesty from the CAGW crowd………..They really don’t know.
“So it’s a big heat pump that brings heat to the Arctic,” says Hay. “That’s not in any of the models.”
and
“There’s no telling how fast it can go with this spike of carbon dioxide we are adding to the atmosphere.”
and
“Nobody has any idea how fast that ice will flow into the oceans once the ice shelves are gone.”
and
“You would expect negative feedbacks to creep in at some point,” says Hay. “But in climate change, every feedback seems to go positive.”
———————————————-
Finally they admit there is uncertainty and they really don’t know.
“That’s not in any of the models”
“There’s no telling”
“Nobody has any idea”
“every feedback seems to go positive”
Was this guy quoting Briffa, Jones, Hansen or Mann?
I wonder if the members of The Team approve of this message?
cn
This table is the average mm/year for all 193 Global sea level gauges over the record that exists.
http://tidesandcurrents.noaa.gov/sltrends/MSL_global_trendtable.html
The average is only 0.80 mms/year. Sealeveldata.info shows the median average of more stations (239) at 1.28 mms/year. So the real sea level increase according to gauges is only around 1.0 mm/year.
Peltier, this summer, recalculated the average land uplift using all world-wide GPS receivers which is estimated at 0.34 mms/year currently. So, one could get to 1.3 mms/year of “global warming-ized” sea level rise per year (including GIA) – actual 1.0 mm/year.
http://www.psmsl.org/about_us/news/2012/peltier_update.php
Gary Lance says:
November 2, 2012 at 5:17 am
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. The Earth does have the potential to create runaway warming and glacier melt. I don’t think it’s likely, but we haven’t tried warming the Earth near the end of it’s interglacial before. The fact is you can’t accurately estimate the time period of the climate change when positive feedbacks are involved.
Your “potential” for runaway warming exists only in the minds of Warmists and in their precious C02-centric climate models. It is a myth. What you, and they fail to consider are negative feedbacks. And please, nobody is warming the Earth, so give that one a rest. Whatever warming effect man is having is negligible.
Harold Ambler says:
November 2, 2012 at 3:19 am
“…at Midway Atoll in the Central Pacific, the National Oceanic and Atmospheric Administration found that sea level rose .7 millimeters a year from 1947 to 2006. At this rate…”
Harold, this is not a good place to measure sea level rise. Indeed, although mentioned in numerous posts (not in the CAGW posts), atolls are living beasts. We have here a coral island that grows to keep pace with sea level rise. This is an interesting record because it is recording, in part, the coral’s determination to keep up with sea level rise. Drilling in atolls (during studies for subsequent atom bomb testing) it was found that the reefal limestones went down a remarkable 120m or so and then into volcanic rock – really not so remarkable because, the coral grew from the 120m lower sea level of the last ice age to keep up with rising sea level of the Holocene. I think studies of “sea level rise” at atoll islands would be an excellent measure of the health of the coral.
Don K says:
“That’s correct except that Manhattan happens to be the first major exception as you move North from Florida. NYC is built on quite old and quite uncompressable Ordovician schists capped with a variably thick layer of sediment and some fill along it’s river fronts in some places. You’d have to know the exact geology of the Battery (which I don’t) to know how much compressable dirt is under the tidal gauge at the Battery.”
That may be true, but completely irrelevant. We’re not talking about sediment compression here, it’s a matter of tectonic subsidence. The whole southeasten US is sinking and you only have to look at the morphology of the Hudson estuary and Long Island Sound to see that NY is no exception, though NY is rather close to the northern edge of the subsiding area. The coast north of Cape Cod shows little evidence of subsidence. What we are seeing is simply that the material displaced by the weight of the Laurentide ice is slowly flowing back to where it came from, and the “bulge” outside the ice is subsiding. Incidentally the “Zero-line” between rise and subsidence is actually slightly inside the maximum extent of the Ice, both in Europe and North America.
daveburton says:
November 1, 2012 at 7:51 pm
and others point out that tidal guages around the US coastline show 2 – 3 mm/yr rise. Some Australian records last year showed the northern coast at 4.8 mm/yr. Which only shows that some places are sinking while others are rising; the global record is either 3.8 mm/yr by satellite with known errors or maybe 1.6 mm/yr with errors corrected. In a way, who cares? Because for sea-level to be up by 1.0m by century’s end means the AVERAGE sea-level rise must be > 10.0 mm/yr (start-point 2000). An AVERAGE 3 – 6X increase from recent historical rates however you measure it.
Once again, the rise is still all in the models.
Academic science should stay in the classroom. Once it enters the political and economic real world, its essential speculative nature becomes forgotten. All of this is not nonsense, but at the beginning of each discussion there should be a poster, left visible the entire time, of the assumptions on which the discussion is based.
Right now in Alberta, Canada, there is an uproar that the oil sands development is going to drive the woodland carribou to extinction. The oil sands apparently covers about 150,000 sq km, though the current operations cover about 450 sq km. (Both of these numbers are probably exaggerated, by the way.) The assumption is that the 21 km square block will be expanded over the much of the 388 km sq block. The project would have to expand by 333X to cover the entire area, or even 83X to cover one-quarter of that area. Is that reasonable?
In my example, the assumption is unfeasible. Regardless of the price of oil, the total area is not going to be developed because not all of the area is equally producible. The true danger to the caribou is probably posed by native hunters who either do not have a hunting season by virtue of their status, or choose to ignore it (as I experienced elsewhere in Alberta: poaching for profit is an endemic problem). But the story rides with those either unable to think critically or unwilling to do so if the result is a weakening of their arguments.
The comparison I am making with sea-level rise studies and the threat to woodland carribou is that both attacks by the eco-green are based on unrealistic – or at least unrecognized and hence non-validated – assumptions. Sea-level measurements are certain in that they are measured, but uncertain in how the measurements relate to an increase in the mean height of the oceans due to increased seawater volume. The “threat” of one meter or more rise by 2100 lies in models of future melting of Greenland and Antarctica with the additon of other water sources. The measurements are based on assumptions of correctness (principally by satellite), the models, on future warming AND melting rates. These are the devils known as details.
The non-technical warmist fails to understand or respect two aspects of scientific study. The first is that initial assumptions about the extension-ability of data from the small to the large are often critical but not critically considered. From the git-go, in other words, the results, whatever they are, are uncertain because the observations may be neither precise nor accurate. (In the liberal sciences of anthropology, Margaret Mead’s work on the Samoan culture turned out to be based on self-serving information given to her by her “subjects”, as a non-climatology example.) The second is that the projection of trends observed in the data rely on assumptions that are also critical but not critically considered. (The rising crime rate of the ’60s was supposed to turn the USA into an out-of-control society a la Robocop by 2000, but the effect of the demagraphic shift to an older population was assumed to be unimportant, which it was not.)
The difference between knowledge and understanding is huge. The impact on bad decision-making is as profound for the expert as for the advised non-expert. The layman warmist considers it nitpicking to question assumptions, but in the case of CAGW it is not. Unfortunately it would appear that the conclusions have to be shown to fail before the premises are questioned.
Geologist Bill Hay means AGW when he says, “global warming”, the climatologists political slight-of-hand. This he reveals when he summarizes another AGW tenet, “in climate change, every feedback seems to go positive”, the necessary but incorrect assumption to make GCMs predict a catastrophe.
The most powerful feedback in Earth’s climate is cloud cover. It is the most powerful because it gates the Sun on and off. It is a rapid, positive feedback to solar variations, amplifying them by the burn-off effect. And it is a slow, negative feedback to global average surface temperature (GAST) by the Clausius-Clapeyron effect, mitigating warming from any cause, meaning dominantly the Sun.
To the extent that Earth’s surface temperature can be modeled as warming (pick a time interval and it is or it isn’t), it is the release of thermal energy stored in the ocean (not Urban Heat Islands) over the last century, plus or minus a half century, and deposited there by the Sun. Global warming, whether positive or negative, is baked into the cake.
And one can estimate GAST by tracking the concentration of atmospheric CO2. The big mystery of Earth’s climate is solved, and it isn’t AGW. Scientists can now get on with predicting solar radiation. Just in time for the election, eh?
“What’s missing from the models used to forecast sea-level rise are critical feedbacks that speed everything up,” says Hay.
“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.”
As others have commented, these are deeply ignorant remarks about the fictitious and longed-for positive feedbacks in climate. It is of course nonsense to talk of a dominant role of positive feedbacks in a climate system that has displayed stability over billions of years.
Someone seems to have woken up to the idea of non-equilibrium dynamics and strange attractors, or “certain stable states” of climate. However Hay is unaware that if positive feedbacks become dominant in a nonlinear-nonequilibrium system then the result is monotonic oscillation, not unidirectional movement. But natural climate oscillation is something they are still desperately trying to ignore or deny.
“Under human prodding, the system wants to go into a new climate state.” In the recent period there are two such states, glacial and interglacial. There is no evidence whatsoever for a third, higher climate attractor within the current global continental configuration. If one wishes to return to eocene warmth, then the Antarctic circumpolar current needs to be blocked and Antarctica needs to be joined to Africa or South America – or to migrate equatorwards. Also joining the Atlantic and Pacific might stir things up as well.
“Make Hay while the sun shines” – pure evidence-free speculation fed to an unquestioning media eating out of the hands of these doom-mongers.
Don K says:
November 2, 2012 at 5:23 am
Gamecock says:
November 2, 2012 at 4:21 am
And, suppose the ocean has risen 3 feet by 2100. It’s the end of the world as we know it?
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Not the end of the world, but a one meter/three foot rise would be getting into the pretty damn inconvenient range. There is a LOT of infrastructure built very close to sea level even in/near what we think of as inland areas like Albany, NY or Sacramento.
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That’s some interesting geography, Don! I didn’t realize how low Albany and Sacramento are.
But consider this. As low as the Hudson is at Albany, Green St. is at 22 feet elevation. Grand is at 54 feet. Safe for centuries. If Albany had to move 500 yards in 500 years it would be no BFD.
Look at Las Vegas. The casinos, which are the most interesting part part of Vegas to me, have been migrating SSW to where Belagio, representing the newer part of the strip, is 1.5 miles from Stardust, the older part of the strip. In effect, Las Vegas has moved 1.5 miles in 50 years.
People will adapt. The alleged rising over generations will be virtually unnoticed. No one in 2100 will care where sea level was in 2012, as we don’t care where it was in 1912.
““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.””
Would anyone care to ask Hay to justify this statement with reference to any facts?
RE: Larry Ledwick (hotrod)
Small point but latch up only achieved with gain and negative roll off changing feedback phase.
With no gain O/P become 1/(1-b) b = feedback. If b>inf then unstable.
But your general point is climate scientist understand F.A. about control system theory and as for starting with 2nd orger approximations in a non linear chaotic multivariate system, well the mind boggles. They ought to have a go with multivariate analysis and try and surmise why the earth has adapted for the few billion years of existance.
I apologies in advance, but the map legend has 2 meters = 16.4 feet versus the actual 13.1 feet. A minor mistake, but it begs the question, to whether the entire paper was as poorly proofed for similar mathematical errors.
Earlier in the week there was an interesting BBC programme on the Greenland glaciers and then the resultant icebergs .
Whilst they talked about warm waters eating the underside of the bergs they made no comment about the astoundingly dirty glaciers (presumably soot from China) which must be absorbing considerable warmth from the sun. Just such a scenario of dirty glaciers (soot from US industry) and warm waters was described by the early scientific expeditions to the arctic by such as Scoresby in the 1820’s.
Anyone got any specific knowledge on glacial soot and its proven effects?
tonyb
Bill Illis wrote on November 2, 2012 at 7:44 am:
“This table is the average mm/year for all 193 Global sea level gauges over the record that exists.
http://tidesandcurrents.noaa.gov/sltrends/MSL_global_trendtable.html
The average is only 0.80 mms/year.”
Bill, that table used to include all 159 of the tide gauges for which NOAA had done trend analysis, but they’ve since separated the U.S. gauges from the other PSMSL gauges, and that table now only includes the non-U.S. PSMSL gauges. The two lists of gauges are here:
http://tidesandcurrents.noaa.gov/sltrends/sltrends_global.shtml
I’ve recombined the two tables, and calculated the averages and medians from the resulting 239-station list, on my web site: http://www.sealevel.info/
The results for NOAA’s current list of 239 tide stations are similar to what you calculated:
Average: 1.02 mm/yr
Median: 1.28 mm/yr
GIA-adjusted average: 1.68 mm/yr
GIA-adjusted median: 1.48 mm/yr
The results for their earlier list of 159 tide stations are similar:
Average: 0.72 mm/yr
Median: 1.15 mm/yr
GIA-adjusted average: 1.51 mm/yr
GIA-adjusted median: 1.40 mm/yr
For that list of 159 tide stations, I also calculated…
Geographically-weighted average: 1.13 mm/yr
duLapel says:
November 2, 2012 at 9:25 am
The map legend actually says 4 metres = 16.4 feet. As you point out, that is incorrect … but then so was your claim that the legend has 2 metres = 16.4 feet.
So, you’ve made the same amount of math errors they have. However, your point is well taken, and yours is a blog comment while theirs is supposed to be a scientific paper. The whole paper doesn’t strike me as being well thought out in any aspect.
w.
Gamecock — in most cases the problem with rising sea levels isn’t that people can’t adapt. It’s the cost of moving infrastructure. e.g. The RR tracks on the East side of the Hudson are built mostly on fill a few feet above Spring flood levels. Raise the estuary level and eventually they will have to raise a hundred or so miles of track to match. Likewise marinas, houses, sheds, etc. in 2011 when record Spring rains lifted Lake Champlain a foot above its previous record level, a rather impressive collection of problems resulted including water sloshing over a section of US2 connecting Grand Isle County to the rest of Vermont. A couple of places in the US — NOLA and Sacramento — are likely to have major levee problems. Likewise overseas. I’m not sure how much margin the Netherlands dikes have (They rebuilt a lot of stuff after the 1953 floods). Then there are those damn overpopulated low elevation coral islands. I expect the inhabitants lack the patience to wait for coral growth and storms to raise their islands to their previous extent.
Gary Pearse said
“I think studies of “sea level rise” at atoll islands would be an excellent measure of the health of the coral.”
I volunteer to carry out an immediate in depth six month study of coral atolls in the warm Australian seas. It is pure coincidence that the Northern Hemisphere winter has just commenced and our soaring fuel bills means the central heating will have to be rationed.
I am so selfless…
tonyb
Anybody going to be in the Charlotte, NC area on Sunday to call this guy out?
A mm here, a mm there, and pretty soon you’re talking about cm’s!
daveburton says:
November 2, 2012 at 5:48 am
An interesting & valid point! I wasn’t aware that was how they managed to fiddlie the figures on that score, but it does not surprise me at all! Nils Axel Morner did say that there was no change in the average rate of sea-level rise of around 230mm/year, & that a change could only be made by playing around with the raw data until a change could be created! HAGWE 🙂
We geologists have largely stood above the fray with a very long view of the earth’s climate. Our taken-for-granted knowledge within the science was unknown to the astronomers, physicists and the like who started all the hysteria. Naturally, the newcomers noting a modest rise in the 100+ year old temperature records and assuming that the earth has had a fairly constant climate, they asked, “What could be the cause?”. Turning their telescopes on Venus, the culprit was clear to them – here is a planet with thick CO2 atmosphere that isn’t too far from being incandescent. The modern CAGW was born and the spokesmen for it were physicists and astronomers.
One way to look at the trillion bucks spent on studies (by physicists and astronomers first and then by sociologists, psychologists, economists, biologists ….) and the construction and costs of (non)alternative energy is that this has been the cost of this group getting a reluctant education in a sphere of knowledge already acquired by geologists – a tradition that is older than the temperature records themselves. The inevitable inconvenient education brought to light earth history, the ice ages, the very warm periods, the dry periods, the wet periods, the Sahara’s green and the Amazon’s savanahs, the antarctic’s tropical home of dinosaurs, the drifting of continents, the rising and sinking of lands, mass extinctions, etc. etc. Closer to the present, came the unwanted knowledge of the more recent natural wide swings in climate, Younger Dryas, Holocene Optimum, RWP, Dark Ages cold period, MWP, LIA, etc. Research and self-fulfilling testing to get rid of these awkward facts that showed the present to be not special at all.
Just when the projections of doom have, perforce, been moderating in the face of this expensive and reluctant education, along comes a johnny-come-lately GEOLOGIST. I don’t know this Dr. Hay but I would put him in the mid 30s to 40 age group who just woke up to the potential for research cash on the subject of CAGW.