In 2006, in his famous documentary, An Inconvenient Truth, Al Gore claimed sea levels would rise by 20 feet (six metre).
The Intergovernmental Panel on Climate Change (IPCC) is more conservative, suggesting a rise of no more than 0.60m by 2099 in its 2007 report.
But in March last year a fellow called Robyn Williams, who has a monopoly on the broadcasting of science programs on Australia’s ABC, scared us with claims sea levels could rise by over 100 metres in the next century because of increases in the rate of ice melt in Greenland and western Antarctica.
A study of sea level rise from ice melt in Greenland and western Antarctica has just been published in Science and concludes that a rise of 0.8 metres is possible by 2100, but MORE** than 2 metres “physically untenable”.
Research scientists W.T. Pfeffer, J.T. Harper and S.O’Neel calculated how much ice and water would need to be lost from Greenland and Antarctica for a two metre rise, then how fast contributing glaciers would need to move in order to dump that much ice, and concluded that a two meter rise in sea level by 2100 would require significantly faster ice velocities than had ever been reported before.
Of course at the moment it is unclear how much warming is actually occurring at the Antarctic, with some suggesting a general trend of cooling there in accordance with the recent global trend. But if the melting starts again at the Antarctic, and continues in the Arctic, it is perhaps reassuring to know, that even under a worst case scenario sea levels should not rise by more than 0.8 metres in the next 100 years.
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** I’ve added the word ‘more’ included to the title of this piece as Pfeffer et al claim it is physically untenable to suggest a rise of more than 2 metres – not up to 2 metres as I suggested in the original post. Thanks to Luke and others for pointing this error out.
Kinematic Constraints on Glacier Contributions to 21st-Century Sea-Level Rise, W. T. Pfeffer, J. T. Harper, S. O’Neel, Science, 5 September 2008:
Vol. 321. no. 5894, pp. 1340 – 1343. DOI: 10.1126/science.1159099
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Sea levels have been increasing at 3.2 mms per year (although over the past two years, the figure has fallen to about 1.0 mm per year.)
All the global warming advocates have a big problem with simple metric math in regards to sea level.
3 mms per year times 100 years equal 30 cms or just 1 foot.
Over the last 15 years, sea level has increased just 1.7 inchs. In terms of the tides, one couldn’t even notice 1.7 inches.
The only way to get these extremely exagerated figures of 2 metres by 2100 is to assume that sea level change will accelerate from 3 mms per year now to 40 mms per year by the year 2100.
In other words, all these sea level rise estimates are still based on climate models and exageration.
I wish they’d tell us something we don’t know, like when will Al, Tim, Robyn, Krudd and all the other fraudsters be exposed.
Sometime soon I hope saving all the world’s taxpayers a cool trillion or two.
Take a look at the following paper showing Antarctic temperatures:
Schneider, D. P., E. J. Steig, T. D. van Ommen, D. A. Dixon, P. A. Mayewski, J. M. Jones, and C. M. Bitz (2006), Antarctic temperatures over the past two centuries from ice cores, Geophys. Res. Lett., 33, L16707, doi:10.1029/2006GL027057
It clearly shows no warming trend in Antarctica. Links and analysis can be found here:
http://www.trevoole.co.uk/Questioning_Climate/_sgg/mf_1.htm
Compare the title to the conclusion.
what about global cooling meantime?
How shonkadelic of them. Like we should be worried:
http://icecap.us/images/uploads/SeaLevel_TOPEX.jpg
http://icecap.us/images/uploads/HANSEN_AND_CONGRESS.jpg
Thanks, JD. No sign of any hockey stick any time soon. Even the 30cm/pa figure is a bit suss given that more than 200 years of Fort Denison in sydney harbour shows no such 60cm rise.
The really interesting policy hole the bimbocrats have dug for themselves is that most of the cleared land around our coastal cities is at or below the 2 metre AHD mark. So any regional development plan that excludes housing development in areas lower than the bull$hit 2 metre sea level rise will mean a disproportionate area of forested land is cleared instead.
Tough $hit, ecogimps, the problem is all your own making.
What an amazing post: Spin-o-saurus rex.
(1) so we’ve now turned a possible increase in sea level rise into a reduction (no – I don’t class Gore of Robyn Williams as source at all – they’re pollies/journalists)
(2) but even 2 metres “physically untenable”. – NO IT DID NOT SAY THAT – the paper said “that increases in EXCESS of 2 meters are physically untenable.”
(3) “unclear how much warming is actually occurring at the Antarctic,” – is it unclear? says who? I thought the Peninsula was warming faster than anywhere. Oh yes that’s right – it’s the volcanoes isn’t it 🙂
(4) “with some suggesting a general trend of cooling there in accordance with the recent global trend. ” DOUBLE BUNK – well maybe cooling in the interior if you want to split decimal points – I would have said still cold and we know why; and the the interior Antarctica trend has not followed the world trend at all. Haven’t we been over this at least 6 times !!
Well tough doo-doos indeed as it seems Mottsa (as usual) hasn’t got it right.
http://www.coastalconference.com/2007/papers2007/Peter%20Helman.doc
The old Fort Denison ruse eh. And seems to have forgotten about the IPO interaction. Huh wazzat? Which is why it’s best to leave it to the experts. Now let’s see what large Pacific oscillation may have just flipped…
So if 0.8m sea level rise over a century is the worst case, what are the other probable outcomes and what is their relative weighting? A worst case is usually going to have a probability in the order of 10%.
There will also be an opposite extreme case of an actual decline in sea level. As the even the IPCC has conceded, no more than half of the past temperature change can be attributed to CO2 with the other half being cyclical change. And this cyclical upturn is just as likely to have a commensurate cyclical downturn that will be capable of cancelling out further AGW. But if the IPCC is only a little bit wrong and AGW only accounts for 33% of past warming then the cyclical downturn will be capable of more than compensating for AGW, producing an actual decline in temperature, as seen in the past decade with a resulting decline in sea level.
It is entirely reasonable to attach a probability of about 10% to this decline.
The next two less extreme outcomes would be something like 20% no change in sea level and 20% sea level rise of about 0.4m per century. And that leaves a big 40% probability in the middle that things will go on just like they have been, with a modest rise of 0.2 to 0.3m rise over the next century.
These probabilities are obviously quesstimates but at least the whole range of guesstimates are presented in one statement. The Klimate Klingons haven’t even got that far, content to grasp the worst outcome in the pack and run with it.
I am posting letters at the new community page, including this comment from Elizabeth (Jo) Page about the Arctic in 1818
http://jennifermarohasy.com/blog/2008/09/not-much-ice-at-the-arctic-in-1818/
Luke,
Interesting paper but you do worry about computer modelling based, among other things, on aboriginal middens.
Particularly when SL changes are only small.
But it is interesting to see that the model recorded the MWP as higher SL than present.
Maybe that’s just ice age rebound?
Remember 4,000 years ago sea level around Australia was at least 1.5metres higher than today, so what happened then I wonder?
This post in favouring Robyn Williams’ outrageous claims ignores ABC’s science advocate Bernie Hobbs who has a ‘calculator’ on the impact of global warming to educate our children at http://www.abc.net.au/science/planetslayer/greenhouse_calc.htm
An example of the balance and accuracy the ABC brings to the debate.
“Sometime soon I hope saving all the world’s taxpayers a cool trillion or two.”
I don’t know about soon, but when it happens it sould spark the next economic boom. Remember the ‘peace dividend’ from the end of the Cold War. It turned out to be short lived, but it did give rise to a golden period of global economic growth between 1995 and 2005. The removal of the spurious taxes, burdens and imposts of climate control freakery is the turbo boost the global economy needs right now.
Are you sure that wasn’t Robin Williams? He’s a comedian from the States. Remember Mork and Mindy?
The warming enthusiasts who run the Argo sea temperature project recommend the paper by C. Domingues and colleagues (Nature, Volume 453, June 19, 2008, pp 1090-1093). Their estimate is 15 cm over the next 100 years.
Insignificant – in capitals, bold and underlined.
Spanglers – the midden erosion was measured as well as other features in Byron area. Movement and erosion of shoreline occurs in high storm phases that seem correlated with IPO activity – sort of inverse for rangeland droughts. Slow and linear is not the model – nothing for decades then lots is the way. Episodic ! But rate of change subtle and not generally noticed in human terms.
An interesting report with photos and graphs on graph paper on sea level rise in Tasmania can be found at http://www.john-daly.com/deadisle/index.htm#appendix
It suggests a sea level rise since 1888 of only 2½cm, the report states this small rise of 2½ cm is fully consistent with a survey of long-term tide gauges around the Australian coast carried out in recently by the National Tidal Facility in Adelaide, which found a sea level rise rate of only 0.3 mm/yr, equivalent to a sea level rise of 3cm over a century.
There is also a discussion on the Fort Dennison record as an appendix.
Helman doesn’t appear to have included vegetation change in any of his calcs, just allocating all change to climate change. Just another bit of cheap propaganda at tax payers expense. And he got to hang out at the Belongil “beat” while doing so.
Well hang dog boy – you’ve come up against one of those fastidious studies that is liable to cause a bad case of redneck cogneetive diss-son-nance.
The Helman paper is interesting, but suffers the usual dichotomy; IPO and other natural events are listed as strongly correlative factors to sea rise, and then AGW comes in the back door to sustain predictions of imminent and larger than preceding sea rise.
The Fort Denison link is good, and like the Helman link alludes to Tasmanian records; in fact Port Arthur is the longest sea level record in the Southern Hemisphere;
http://soer.justice.tas.gov.au/2003/casestudy/4/index.php
The record shows that since 1841, up to 2003, sea level rose 13cm, or 0.08mm PA. Obviously, as luke says, that wouldn’t be a linear rise; but with so little rise, there could hardly be many sudden and ‘large’ rises.
Sorry cinders; that link of yours covers the Port Arthur sea level history in detail; I only looked at the Denison appendix.
GEOPHYSICAL RESEARCH LETTERS, VOL. 34, L01602, doi:10.1029/2006GL028492, 2007
On the decadal rates of sea level change during the twentieth century
S. J. Holgate
Proudman Oceanographic Laboratory, Liverpool, UK
Abstract
Nine long and nearly continuous sea level records were chosen from around the world to explore rates of change in sea level for 1904–2003. These records were found to capture the variability found in a larger number of stations over the last half century studied previously. Extending the sea level record back over the entire century suggests that the high variability in the rates of sea level change observed over the past 20 years were not particularly unusual. The rate of sea level change was found to be larger in the early part of last century (2.03 ± 0.35 mm/yr 1904–1953), in comparison with the latter part (1.45 ± 0.34 mm/yr 1954–2003). The highest decadal rate of rise occurred in the decade centred on 1980 (5.31 mm/yr) with the lowest rate of rise occurring in the decade centred on 1964 (−1.49 mm/yr). Over the entire century the mean rate of change was 1.74 ± 0.16 mm/yr.
Decadal Trends in Sea Level Patterns: 1993-2004
http://ocean.mit.edu/~cwunsch/papersonline/sea_level_5may2007.pdf
“At best, the determination and attribution of global mean sea level change lies at the very edge of knowledge and technology. The most urgent job would appear to be the accurate determination of the smallest temperature and salinity changes that can be determined with statistical significance, given the realities of both the observation base and modeling approximations. Both systematic and random errors are of concern, the former particularly, because of the changes in technology and sampling methods over the many decades, the latter from the very great spatial and temporal variability implied by Figs. 2, 6, 8. It remains possible that the data base is insufficient to compute mean sea level trends with the accuracy necessary to discuss the impact of global warming–as disappointing as this conclusion may be.”
This link to the long term trend in sea level shows no acceleration, but a constant rate of increase.
http://en.wikipedia.org/wiki/Image:Recent_Sea_Level_Rise.png
Published papers show there is a decadal fluctuation in the rate of sea level rise, and the current rate has not broken through that variation. Thus the current rate cannot be attributed to AGW. Plus, there is a serious logical problem with linking this rate to anthropic global warming. CO2 emissions over the same period has not been linear, but in fact follows a classic growth curve.
http://commons.wikimedia.org/wiki/Image:Global_Carbon_Emission_by_Type_to_Y2004.png
From 1850 to 1945, when we experienced a large proportion of the warming, our emission level went to 1200 MMTC/Yr, a mere 14% of today’s level. From 1945 onward we saw an 8 TIMES increase in CO2 emissions which comprises 86% of the total increase since 1850. Yet half that time, 1945 to 1975, the planet cooled right when the rate of CO2 emissions increased 4 TIMES. Half of the increase in CO2 has been in the last 40 years, the last 10 of which the planet has not warmed in spite of a 20% increase in CO2 emissions.
Since sea level rise has not changed its’ rate over this entire period one has to question if any of the current rate has anything to do with AGW. If there were a correlation one would have expected to see some sort of “hockey stick” in the rate of sea level rise. But it’s not there.
This has serious consequences for AGW theory
But we do know that sea level around Australia was 1.5 metres higher 4,000 years ago so what caused this increase I wonder.
Also I’m fairly sure that had you wished you could still walk to Tasmania approx 12,000 years ago (10,000 BC) after the end of the last ice age.
In the intervenig 6,000+ years there was a rapid warming, then from 2,000 BC to whenever the level dropped again and is supposedly rising slightly now every year .
Amazing what the climate can do all by itself isn’t it?
Or did I miss all those coal fired power plants, cars , planes, factories, modern commerce etc thosands of years ago?
Cohenite – Helman’s research is quite new. The paper above is only a sprinkle – the main meat is in his recent thesis (see refs) and coming papers. But a very detailed investigation – into old survey records, lots of history, heavy metal wash chemistry on beaches, knotty aspects of early tidal measurements.
With things like the IPO sea level rise is confounded in these multi-decadal influences.
But the movement of beaches is subtle – people’s longer term memories are poor – and he suggests that any erosion sequences are not linear — they are sporadic and with the IPO type influences, episodic in clusters.
Given the investment in real estate in areas like Byron – would have thought any landholders might be glad to have some longer term historical perspective on their water front history.
Yes luke I’ll follow up Helman; Richard Wakefield’s links are interesting.
As to Byron; not having the wit to buy there in the ’70’s when I was surfing split rock, IMO, the unjustly enriched NIMBY’s who did buy, can learn to eat their soy under water and with spiro, the resident great white, for company. How’s that for sour grapes?
The sooner “Booring Bay” is innundated the better, preferably catastrophically so.
And I do hope Helman took the extensive modifications of every river mouth in the survey area into account? Hint – breakwaters seriously alter coastal sand flows and did produce major erosion problems. The fact that they might have coincided with the PDO or the variations in Al Gore’s rectal thermometer mean absolutely jack $hit.
So tell us, boy wonder, how did he distinguish between these major impacts that have had zero climatic input?
There’s nowhere for the sea level rise to come from.
The Antarctic ice isn’t melting. Since we would need to increase the temperature another 50 degrees to get it within a coo-ee of melting point. And then have to deal with the latent energy of melting.
The arctic has already melted mostly and its sea-ice anyway. Which doesn’t affect sea level when its melted.
That leaves only Greenland. Its melting is slow and since we are cooling and not warming this melting will eventually level off and may even go backwards. So quite contrary to the sea level continuing to increase by its background 2mm a year or so, its far more likely that it will flatten out.
Robin Williams ought not have this monopoly. He may be alright as a journalist. He’s no scientist. Never could be.
Does anyone know if sea level dropped during the little ice age up until about the 1770’s?
It probably did drop a little bit didn’t it?
If so this is the more likely scenario we ought to be expecting. A flattening of the rate of sea level rise or the sea level dropping a little bit by 2100.
Birdy do you really dress like that?
So tell us how Helman dealt with the breakwaters, Luke? Oh Luuuukey?
Lets have that evidence Luke.
“The rate of sea level change was found to be larger in the early part of last century (2.03 ± 0.35 mm/yr 1904–1953), in comparison with the latter part (1.45 ± 0.34 mm/yr 1954–2003). The highest decadal rate of rise occurred in the decade centred on 1980 (5.31 mm/yr) with the lowest rate of rise occurring in the decade centred on 1964 (−1.49 mm/yr). ”
Damn that is just so interesting. Some checking might lead to the conclusion that extra solar activity could lead to sea expansion as THE FIRST AND QUICKEST reaction as opposed to the apparent build-up in joules in the upper oceans.
That could be totally wrong but one ought to be tracking down exactly why the expansion is there.
Like in economics you might think that monetary expansion would lead right away to consumer price inflation. But usually it tends to spill into trade deficits and investment asset inflation first.
So its important to figure out how these extra joules manifest themselves right away.
Does anyone have the records of how the oceans have gone after solar activity peaks and forbush events?
Or in relation to the yearly cycle of the planet getting closer to and further away from the sun?
If we saw a sea-saw of ocean levels in relation to the earth getting close to the sun and if the rise preceded the rise in air temperature… and same again in response to forbush events that could tell us something.
Don’t you just love the way poor old Luke’s brain works. He makes a big deal about whether the reference was to “rises of 2 metres” being untenable, or “rises in excess of 2 metres” being untenable. The turkey would have us believe that a rise of 2.1 metres might be untenable but a rise of 1.9 metres can rip it’s clothes off and bask in the glory of “super prediction”.
Get this straight, boy bogan, the transect from the tenable to the untenable is a continuum and the gradients are essentially proportionate. Unless, of course, you have an imagination that has been subject to chemical modification.
The unambiguous conclusion is that any sea level rise projection that is above 1 metre for the century is approaching the very limits of the tenable.
Personally I think we will wind up going flat or the sea level dropping a bit. Because we’ve really run out of places where the extra water might plausibly come from. Particularly during a period of general cooling.
I just wish I knew where to find good graphs about this. Whether the sea level rise flattened between about 1400 and 1750. Flattened or dropped. Not knowing one way or another I’d suspect that it dropped.
Or whether sea level responds quickly to outsized solar energy punching into the ocean, quite apart from any background melting going on.
Taking both melting and sea-water expansion into account, sea level might be a really good proxy for cumulative joules in the climate system.
With this avalanche of indecisive studies clogging things up you cannot seem to find out what you really want to know.
http://www.cmar.csiro.au/sealevel/images/alt_gmsl.jpg
Here’s the best graph I can find and its from our own CSIRO. I perceive an “OUT” for the former alarmist who is fast enough on his feet.
Supposing you were to make the wild conjecture that the best measure of joules accumulated in the system, when considering the short-term as well as time-scales relevant to human history is SEA LEVEL HEIGHT.
Its not such a bad conjecture that this simple measure might be even better than the system of buoys they have got going out there. For one thing you have more of a chance of estimating ancient data with this simpler measure. And for another thing temperature measurements aren’t going to be enough. Because a lot of latent energy ought to be tied up in thermal expansion. On top of that there is a great amount of latent energy of melting. Also the buoys don’t go down all the way.
So its not an implausible conjecture but we need the empirical evidence for or against this idea. Or whatever the data tells us.
Now check out the graph. See how the black line peaks and falls every year. This is definitely in line with the earth moving closer to and further away from the sun. We therefore want to see what the delay is. The most energy will have accumulated not on the day when we are closest to the sun. But some time after that. Just as the day is warmer usually at 2.00pm than it is at noon.
So researchers ought to be trying to figure out what the delay is here. The delay between theoretical peaks in total joules in the system and the peak in sea level. Nonetheless one would think that the expansion would react pretty quickly.
Now from a pure atmospheric temperature point of view we see that the warmest year was 1998. And from measurements of imbedded energy in the oceans (I don’t know if they are corrected for thermal expansion and melted ice) we see the peak coming around late 2003 I think. And a pretty weak drop-off but then they’ve corrected this at least twice and I haven’t seen a good updated set of graphs for this.
But here’s a good excuse you alarmists can put together for taking too long to come onto the side of righteousness and I’ll give it to you for free.
And that excuse is that you were using the sea level as your ultimate metric of cumulative warming. That way you can say “How can you blame me? Look when my favoured metric turned down? It didn’t so much as flatten until 2006-2007 and I didn’t have the 2008 data. There wasn’t even a trend established.”
There you are. You better run with it and try to avoid the mass-sackings that I hope will come to pass. I hope none of you avoid the axe but there you are. You ought to move quickly.
The above is also the best response I can come up with for an idea that Mitchell Porter had awhile ago. He was asking here and at the beloved Professor Brooks’ blog whether the expected CO2-effect could have been subsumed into the ice melting. I don’t see any convincing evidence for non-negligible CO2-warming at all. But at least looking at both melting and thermal expansion would give people something to think about.
Can anyone point me in the right direction to figuring out how many extra joules are implied by a (lets say) one centimetre rise in ocean sea level?
Just on first principles. Ignoring any effect on the mantle. Ignoring melting. Ignoring changes to the atmosphere in the way of air pressure or changes. Ignoring loss of liquid water to the atmosphere through higher water vapour levels.
I read an estimate of the joules held by the atmosphere as 10 to the power of 22 joules. Don’t know how close that is.
For the ocean to expand by 1 centimetre there would be some joules going into the increase in temperature and some joules going into the physical expansion. Or you could think of it that way.
So has anyone tried to figure out how many joules that would take?
The studies I’ve seen try and attribute sea level increase to “global warming” and its not clear they talk a great deal about joules in this regard.
The ten-to the power of 22 joules estimate is for the oceans. Not for the atmosphere.