Another sea level rise fallacy falls short

Heat-driven expansion not a major source of sea level rise

With the power to drown low-lying nations, destroy infrastructure, and seriously affect sensitive coastal ecosystems, sea level rise may be one of the most readily apparent consequences of global warming that is already under way. However, the sources of the rising waters, and the dynamics driving them, are not so clear. Melting land-locked glaciers, shrinking ice sheets over Greenland and Antarctica, and the ocean’s thermal expansion will all play a part, but the expected contribution from each of these sources is still up for debate. Previous studies have suggested that thermal expansion driven by rising sea surface temperatures will account for up to 70 percent of sea level rise in the near future, but research by McKay et al. suggests this may be a drastic overestimate.

The authors draw on paleoclimate records and model simulations of the last interglacial period, when the sea level rose by more than 6 meters (19.7 feet), to isolate the contribution of thermal expansion to sea level rise during a previous period of global warming. The authors found that during the last interglacial period, between 130,000 and 120,000 years ago, the global average sea surface temperature changed between 𔂾.4 and 1.3 degrees Celsius (-0.7 and 2.3 degrees Fahrenheit). On the basis of research into the temperature sensitivity of thermal expansion, the authors suggest that between 𔂾.2 and 0.7 m (-0.66 and 2.29 ft) of ocean rise would have been attributable to thermal expansion. With thermal expansion playing such a small role in the pronounced sea level rise during the last interglacial, the authors suggest that the Greenland and, in particular, Antarctic ice sheets may be more sensitive to increasing temperatures than previously thought, with important implications for estimates of future sea level rise.

Source:

Geophysical Research Letters, doi:10.1029/2011GL048280, 2011

http://dx.doi.org/10.1029/2011GL048280

Title: The role of ocean thermal expansion in Last Interglacial sea level rise

Authors: Nicholas P. McKay: Department of Geosciences, University of Arizona, Tucson, Arizona, USA;

Jonathan T. Overpeck: Department of Geosciences, Institute of the Environment, and Department of Atmospheric Science, University of Arizona, Tucson, Arizona, USA;

Bette L. Otto-Bliesner: National Center for Atmospheric Research, Boulder, Colorado, USA.

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the authors suggest that the Greenland and, in particular, Antarctic ice sheets may be more sensitive to increasing temperatures than previously thought
who would have thought

Katherine

Typo alert: Anoter sea level rise fallacy falls short should be “Another sea level rise fallacy falls short”

Morley Sutter

Typo in heading: “Anoter” should be “Another”.

Here we go again: “[might be] worse than we thought”, while continually reminding us that it is sea SURFACE temperatures that they discuss. In short, an insignificant volume of the total sea, yes? So what is the fuss about? Who, aside from themselves, are they trying to frighten?

Patrick Davis

Tell that to the people of Japan. LAND levels FELL at least 1m as a result of the quake movements this year, and are STILL shifting. So it appears only alarmists assume land levels are static and sea levels change.
And there is the money grab sound bite “model simulations”…it has to be true ‘coz it’s on a computer and in full 1080p HD colour.

I don’t see the message here. They are saying that thermal expansion was a small fraction of a 6m rise. Well, yes – if we are to have a 6m rise, the thermal component would also be a small percentage. Do you expect that?

Another paper to reinforce GRL’s post-rational reputation. More funds required to investigate the magical properties of polar ice.

TBear (Warm Cave in Cold-as-Snow-Sydney)

Maybe the aliens will have the answers.

Andrew Harding

Mike Bromley the Kurd says: ” Here we go again: “[might be] worse than we thought”, ”
It always is, that is why I am 100% sure that they are lying through their teeth. It is not in the nature of the warmists to err on the side of caution with regard to their computer models. A sea level rise of 2 inches in 100 years does not get headlines a sea level rise of 30 feet does, especially if followed by the statement this is worse than the 20 feet our initial computer models predicted. There is no getting away from the fact that somewhere in all the data that has been collected there has to be results showing that global temperature increases/ sea level rises are less than predicted. This is in the very nature of statistics, but we the general public are not privy to it. Neither I suspect are the politicians. I would also say that all of this propaganda as well as it’s content cherry picked, so is it’s timing. There were very few press releases in the UK last winter, and any debate used the phrase “climate change” as opposed to “global warming”. Now that summer is here we are back to “global warming” ( not that that is very convincing in UK this summer!!). They might not be very clever with regards to what is actually happening to the climate, but they surely are when it comes to propaganda.
Josef Goebbels would be proud of them!!

Nick, I have trouble with evidence for past melting of land ice in the Antarctic. Nobody appears to have demonstrated an unconformity or disconformity in Antarctic ice layers indicative of past erosion of any large type or scale. It sems to be assumed that the annual record is preserved. If we use Vostok, with its admitted data imperfections, can we not comfortably assume that failure of the land ice sheet to melt in the last 700,000 years is comforting for the immediate future? To the contrary, the measurable several km of ice thickess would seem to indicate accumulative mechanisms that favour lowering ocean levels. Have you seen evidence of past melting on either Greenland or Antarctica, of a type that could change ocean levels substantially? Any references?

LeeHarvey

I’ve been telling anyone who would listen that when people talk about sea level rise due to thermal expansion of water, they’re forgetting about a little concept called thermoclines. You may warm the surface five degrees, but once you get a hundred meters down the temperature isn’t going to change a hell of a lot. The dynamics of a large fluid body with the unique properties of water – it starts getting less dense with decreasing temperature below 277 K – dictate that you can’t warm the whole thing from the surface and expect it to expand. You’re actually going to find that any water that is below 277 K (and there’s a whole lot of it in the deep oceans) will contract and drop sea levels if its temperature increases.
The fact that many people have devoted doctoral theses to deep ocean dynamics should be an indication that the problem is slightly more complicated than simply applying the thermal expansion coefficient of water at an arbitrary temperature to the entire ocean.

Katherine

With thermal expansion playing such a small role in the pronounced sea level rise during the last interglacial, the authors suggest that the Greenland and, in particular, Antarctic ice sheets may be more sensitive to increasing temperatures than previously thought, with important implications for estimates of future sea level rise.
It might be worse than we thought! Send money so we can be sure!
Heh. Considering that we seem to be on the downslope of the current interglacial, catastrophic sea level rise isn’t much of a concern.

Alan D McIntire

Since the discussion is about sea level, there ought to be a link to
http://sealevel.colorado.edu/
Admittedly 1 year is not significant, but it looks like sea levels took a dive in 2011

John W

So, if the sea level rise hockey stick is correct(lol) and it’s not from thermal expansion then there must also be a hockey stick in land locked ice volume loss. Another Mann paper for sure.

If sea level rise is mainly due to melting land ice, then that melting ice has removed a lot of heat in the form of latent heat of fusion. Water at 0°C has a much greater heat content than does ice at 0°C. Adding cold water to the ocean must lower the average heat content., and therefore the temperature, or at least partially offset any warming.Since the added cold water is close to the land ice, it has a negative feedback effect on local air temperature. I seem to recall a paper published maybe last year on this effect around Greenland.

Bruce Cobb

The Eemian basically only lasted about 11k years, but hung on in Europe for another 12k. The current interglacial is getting somewhat long in the tooth. Most of the melting action took place during the first hundred years. Sorry, warmies, but sea level rise is only going to continue at its current snails pace of roughly 4 to 6 inches per century. If anything, Antarctic ice is expanding, and Arctic ice melt has slowed to a crawl. The future for climate alarmism looks dim. I suggest they seek another line of work. Perhaps palm reading or tarot cards would be up their alley.

Corey S.

Here’s a copy, though maybe not the finished product.
The role of ocean thermal expansion in Last Interglacial sea level rise
http://www.leif.org/EOS/2011GL048280-pip.pdf

A G Foster

Whatever component of U Colorado’s adjustment was based on increased sea level rather than post glacial rebound, already assumed mass increase due to ice melt rather than rise due to deep thermal expansion, which has the effect of decreasing density and even decreasing bottom pressure, as the water mass is moved inland on mostly northern continental shelves (see http://wcrp.ipsl.jussieu.fr/Workshops/SeaLevel/Posters/7_7_Landerer.pdf).
According to Landerer’s model thermal expansion, depending on its depth, will have a negligible or slightly decreasing effect on LOD, whereas a melting Antarctic should increase LOD. Current decreasing LOD then suggests lots of new snow at the poles, and/or continued rebound probably more from the Little Ice Age than from the Last Glacial Maximum. But core/mantle coupling provides a convenient deus ex machina–up to a point. –AGF

Magnus

“The authors draw on paleoclimate records and model simulations of the last interglacial period”
Sounds like rock solid, fact-generating, effin science. Just give ’em a trillion to start fixing this thing right away.

John

Anthony, should there be a clarification regarding this statement: “The authors draw on paleoclimate records and model simulations of the last interglacial period, when the sea level rose by more than 6 meters (19.7 feet).”?
Do you mean that the sea levels in the previous interglacial, at their peak, were 6 meters higher than today?
Sea levels rose in this interglacial by about 350 feet, from the depth of the last ice age to the present, and mostly likely did the same prior to and during the previous interglacial.

A G Foster

Antarctica and Greenland don’t melt much during the “interglacials”; it’s North America and Eurasia that fluctuate. Only if ALL the ice melted would you get a rise of 100 meters.

Richard Wakefield

Question. Isn’t only the top few feet of the seas that gets warmed by the sun before plunging down to the cold depths? Hence the thermal component of the oceans must include the entire cold depths? Is there any indications that the deep oceans are warming/cooling?

Joshua

Speaking of worse than we thought:
–snip–

Across the globe, plants and animals are creeping, crawling, slithering and winging to higher altitudes and latitudes as temperatures climb….The new analysis reexamined more than 100 previous studies to give a global picture of altitude shifts in 23 groups of plants and animals and latitude shifts in 31 groups. Although Thomas and colleagues found great variation in how far individual species had shifted over the decades, a trend was clear. On average, species migrated uphill 36 feet per decade and moved away from the equator — to cooler, higher latitudes — at 10 miles per decade. The rates are two to three times those estimated by the last major migration analysis, published in 2003.
–snip–
http://www.washingtonpost.com/national/health-science/up-and-up-plants-and-animals-migrating-as-climate-changes/2011/08/18/gIQAzlTxNJ_story.html?wprss=rss_homepage
Wait – Anthony, isn’t there some snowstorm somewhere that you can post about?
Or, alternatively….
Look!! Squirrell!!

Richard Wakefield

For those who may not know of this, look up Glacier Girl. A P38 that was extracted from the icepack along Greenland’s east coast. A group of WWII planes was forced landed on the icepack. The planes were abandoned. Expaditions found them, and extracted one P38 from the ice. They had to go down some 200 FEET! So if all this ice is melting in Greenland in the last 60 years, how did 200 feet accumulate and bury these planes in that same 60 years? Me thinks these predictions of melting ice are a tad off.

ferdberple

Why is it that scientists are so certain that the understand AGW and the effects, when we continue to hear them say things are worse than they previously thought. Doesn’t that mean that what they though previously was wrong?
Also, if the science on climate change is settled, then why continue to pay money to fund research on the subject? We should halt the funding for research and move to engineering. De fund the scientists and politicians and start funding the engineers and put people back to work building things of value. Scientific studies and the taxes that drive them are not contributing to the national wealth.

ferdberple

“Doesn’t that mean that what they though previously was wrong?”
And if they were wrong previously, doesn’t that make them more likely to be wrong the second time around? Why believe someone with a track record of errors is somehow right this time?

Frank K.

Since we’re talking about catastrophic seal level rise, who could forget this? (From the person who shared half of the Nobel peace prize money for climate change – heh!)
http://newsbusters.org/static/2009/11/Al%20Gore%20Photoshops%20Hurricanes%20Into%20New%20Book%27s%20Cover%202.jpg

Frank K.

Sorry forgot to close my bolding in the previous post…

Andrew30

If water is most dense at 4 degrees C, then if the depths of the oceans are Cooling from 4 dergees to below 4 degrees then that would cause expansion. If there was a very strong el nino then that cools the ocean, heat from below rises, water at depth cools and expands, sea level rises.
Sea level will rise because of cooling or warming, that has to be a eco-rent-seeking climate scientologists wet dream.

A G Foster

Richard Wakefield says:
August 19, 2011 at 7:15 am
No expert here, but I would think the thermohaline system would be slower to respond to temperature changes than would land ice. Accordingly, the now extended drop in sea level (which I for one didn’t anticipate) argues as well against thermal expansion as against land ice loss. The easiest way to map T and salt boundaries is with powerful sonar, but this was decided against decades ago to save the cetaceans’ ears. As you can imagine, it’s no easy task checking the entire ocean at all depths.
And “MostlyHarmless says” at August 19, 2011 at 6:24 am, makes valid points. Ice melts first, cooling the seas; they heat up later (lag time). Additionally, arctic ice insulates the ocean; once removed the seas are exposed to release their heat to the arctic air (inverse relation). –AGF

An Inquirer

Alan D McIntire @ August 19, 2011 at 5:55 am: You might be aware that the chart to which you linked incorporates an adjustment of .3 mm per year to account for continental rebound (from last ice age). According to the graph, sea levels have crept up 50 mm in the last 20 years; but actually, they have crept up 44 mm relative to land because analysts assume that land has risen 6 mm in those 20 years.

An Inquirer

Richard Wakefield @ August 19, 2011 at 7:15 am: You might be interested in discussions by Dr. Roy Spencer on warming in lower ocean depths. Leviticus observations of ocean temperatures trends reveal that temperature increases fall off quite rapidly after a few dozen meters. http://www.drroyspencer.com/

Doug Proctor

Using the paleoclimate warming of 0.4 – 1.3C seems a little wide for meaningful, useful predictions. Interesting in a generalized way, but with an accuracy like that, what confidence in an extrapolation can you make?
In today’s Calgary Herald (August 19th) worries are expressed about sea-level rise flooding Vancouver with its prediction by “most experts” of a 1.0m rise by 2100. In less than 89 years the sea-level is going to rise 1000 cm, or 11mm/yr. How much is from thermal expansion? Who cares when the prediction requires 3 to 5 times the current rate ON AVERAGE until 2100 (depending on whether you prefer the 1.9 mm/yr tidal record or the 3.4mm/yr satellite record, a difference that is amazingly different itself). And since no records show sea-level rising at an accelerating level, then the actual “average” rate required to reach 1.0m rise by 2100 must be >5 X whatever current rate you choose. And that is likely?
“Huh?” moments arise continually when you read and THINK about what you are reading what comes out of the Gore-Suzuki-Hansen Future Universe.
My point here is that the warmist or just alarmed don’t think things through, don’t look at the actual accuracy or “representation of reality” such research, articles or pronouncements are likely to have. It’s a grown-up version of “my Dad says”, and if you disagree then you have to fight me because you just insulted my father. One day “my Dad” will suggest the experts are full of hooey and that is what you will read, until the title is “Another Zany End-of-World Prediction Falls Flat”.
I/we should look forward to that day, but, man, is it painful coming. Perhaps – hope springs eternal – this 14 September, with Al and his Gorethon, there will be enough WTF moments to make the MSM blink. Beyond the critical 9 already exposed in An Inconvenient Something.
The push to publish to validate one’s existence in academia and justify continued funding is drowning us in trivia. Anxiety-producing trivia for the non-thinker or agenda-driven. Methinks the Vatican was right in resisting the Bible being published in the language of the people: we now know what happens when the smiling masses are invited to think for themselves. (They don’t.)

rbateman

If it’s worse than previously thought, then there is an equally disastrous counter-outcome depending on which state the oceans & Ice Caps are in.
If Global Cooling were to onset, according to their models, the sea levels would drop precipitously, sea Surface temperatures would drop like a rock enhancing Sea Ice extent increase, and the Ice Caps would turn into roving monsters in a few decades.
IF their models are worth anything.
I need big $$$ to study this coming Ice Avalanche.

rokshox

“The authors draw on paleoclimate records and model simulations of the last interglacial period”
I wonder if historical sea levels were in any way used to calibrate the models.

Nuke

Shouldn’t sea level rise be accelerating, if AGW theory is correct? Isn’t this just another failed hypothesis for a failed theory?

Latitude

Nuke says:
August 19, 2011 at 9:13 am
Shouldn’t sea level rise be accelerating, if AGW theory is correct? Isn’t this just another failed hypothesis for a failed theory?
====================================================================
yep cause so far it ain’t moving….
http://stevengoddard.wordpress.com/2011/07/25/monterey-bay-shows-no-change-in-sea-level-or-ph/

John W

RE: Joshua
Really? Do we still not understand that evidence for GW is not evidence for AGW and certainly not evidence for CAGW or that it doesn’t even come close to being any sort of deciding factor between a climate sensitivity of less than 1C or greater than 2C or whether climate sensitivty is simply calculatable or not?

“the authors suggest that between -0.2 and 0.7 m (-0.66 and 2.29 ft) of ocean rise would have been attributable to thermal expansion”
The math says that is 0.25 (+/- 0.45) m. [In the ‘measurement’ community, that’s the signal (+/- noise).]
If the ‘signal’ you are looking for is less than the noise, it is hard to be sure it is there.
If the ‘signal’ you are looking for is less than *half* the noise, you can bet the signal *isn’t* there.

R. Gates

So, what this study basically is saying is expect more of a contribution to sea level rise from the glacial melting coming from Antarctica and Greenland and less from thermal expansion. This goes back to previous points related to the IPCC estimate in 2007– it was too low, as it did not give a significant contribution from Greenland and Antarctica, and more evidence since that time has shown that the IPCC estimate was too low more than half.

Luther Bl.

Nick Stokes says:
August 19, 2011 at 4:32 am
I don’t see the message here.
———
Media Studies not your field then? Could it be “Greenland and Antarctica are doomed!”…

I’m tired of the charts and graphs- deal with it! The true cause of sea level rise is ocean floor volcanic activity,(lava displacement) human effluent discharge from treatment plants, giant cargo ship water displacement, ships sinking, space debris re-entering, meteorite dust, and lastly… more beach goers as the world population increases.

Nuke says:
August 19, 2011 at 9:13 am
Shouldn’t sea level rise be accelerating, if AGW theory is correct? Isn’t this just another failed hypothesis for a failed theory?
———
Yes, to get to 2 meters in 100 years the increase in rate of sea level rise would have to be about 4% per year. 4% has a doubling period of about 22 years, that means in the last 22 years to 2100 sea level would have to increase a meter. Anyone who thinks that is possible is definitely drinking too much coolaid.

Nuke says:
August 19, 2011 at 9:13 am
Shouldn’t sea level rise be accelerating, if AGW theory is correct? Isn’t this just another failed hypothesis for a failed theory?
====================================================================
yep cause so far it ain’t moving….
http://stevengoddard.wordpress.com/2011/07/25/monterey-bay-shows-no-change-in-sea-level-or-ph/
——————–
California is an active tectonic zone, so not an indicator of sea level increasing, more an indicator of what the land is doing in relation to sea level. There arn’t too many places on the planet where tectonics has little influence.

Joe Crawford

With thermal expansion playing such a small role in the pronounced sea level rise during the last interglacial, the authors suggest that the Greenland and, in particular, Antarctic ice sheets may be more sensitive to increasing temperatures than previously thought, with important implications for estimates of future sea level rise.

I guess we should never let reality interfere with “good” science…
However… It seems to me that between the Vostok example of Geoff Sherrington (August 19, 2011 at 5:13 am) and the Glacier Girl example of Richard Wakefield (August 19, 2011 at 7:22 am) the authors of the McKay et al. paper are looking look pretty ridiculous at this point. Of course if you need to make your living from ‘Climate Science’ today, and, you have even the slightest inkling of common sense you must also have developed a pretty thick skin by now.

Bruce Cobb

R. Gates says:
August 19, 2011 at 10:16 am
So, what this study basically is saying is expect more of a contribution to sea level rise from the glacial melting coming from Antarctica and Greenland and less from thermal expansion. This goes back to previous points related to the IPCC estimate in 2007– it was too low, as it did not give a significant contribution from Greenland and Antarctica, and more evidence since that time has shown that the IPCC estimate was too low more than half.
Except that the IPCC’s “estimate” of some 6 to 38″, depending on the “scenario”, were based on some wild assumptions, with very little basis in reality. And now you want to increase those “estimates” by 50%? The C02 delusion is an amazing thing to behold sometimes.

Latitude

jrwakefield says:
August 19, 2011 at 11:04 am
California is an active tectonic zone, so not an indicator of sea level increasing, more an indicator of what the land is doing in relation to sea level. There arn’t too many places on the planet where tectonics has little influence.
======================================================
and it’s no accident that the only places showing sea level rise….
….are right on top of underwater volcanoes
it could not be more obvious when you compare the gravity satellites to the sea level satellites.
http://suyts.wordpress.com/2011/06/25/discussion-so-far/#comments

Nick,
Did you read SteveF’s post over at Lucia’s?.

jorgekafkazar

Richard Wakefield says: “For those who may not know of this, look up Glacier Girl. A P38 that was extracted from the icepack along Greenland’s east coast. A group of WWII planes was [force] landed on the icepack. The planes were abandoned. Expeditions found them, and extracted one P38 from the ice. They had to go down some 200 FEET! So if all this ice is melting in Greenland in the last 60 years, how did 200 feet accumulate and bury these planes in that same 60 years? Me thinks these predictions of melting ice are a tad off.”
Metal objects frozen into ice don’t remain at a constant level. The weight causes the ice beneath to melt very slowly, letting them sink. The 200′ doesn’t all represent accumulated ice.

Nuke

R. Gates says:
August 19, 2011 at 10:16 am
So, what this study basically is saying is expect more of a contribution to sea level rise from the glacial melting coming from Antarctica and Greenland and less from thermal expansion. This goes back to previous points related to the IPCC estimate in 2007– it was too low, as it did not give a significant contribution from Greenland and Antarctica, and more evidence since that time has shown that the IPCC estimate was too low more than half.

By “evidence” do you mean to say “unverified (and unverifiable) computer models” and by “too low” did you actually mean to say “wildly over-exaggerated in order to stir up political activism among the easily mislead proletariat?”