Image: Global Warming Art – click.
See also this recent WUWT story: Freaking out about NYC sea level rise is easy to do when you don’t pay attention to history
From the National Oceanography Centre at the University of Southampton: Global sea-level rise at the end of the last Ice Age
Southampton researchers have estimated that sea-level rose by an average of about 1 metre per century at the end of the last Ice Age, interrupted by rapid ‘jumps’ during which it rose by up to 2.5 metres per century. The findings, published in Global and Planetary Change, will help unravel the responses of ocean circulation and climate to large inputs of ice-sheet meltwater to the world ocean.
Global sea level rose by a total of more than 120 metres as the vast ice sheets of the last Ice Age melted back. This melt-back lasted from about 19,000 to about 6,000 years ago, meaning that the average rate of sea-level rise was roughly 1 metre per century.
Previous studies of sea-level change at individual locations have suggested that the gradual rise may have been marked by abrupt ‘jumps’ of sea-level rise at rates that approached 5 metres per century. These estimates were based on analyses of the distribution of fossil corals around Barbados and coastal drowning along the Sunda Shelf, an extension of the continental shelf of East Asia.
However, uncertainties in fossil dating, scarcity of sea-level markers, and the specific characteristics of individual sites can make it difficult to reconstruct global sea level with a high degree of confidence using evidence from any one site.
“Rather than relying on individual sites that may not be representative, we have compared large amounts of data from many different sites, taking into account all potential sources of uncertainty,” said Professor Eelco Rohling of the University of Southampton’s School of Ocean and Earth Science (SOES) based at the National Oceanography Centre (NOC) in Southampton.
The researchers brought together about 400 high-quality sea-level markers from study sites around the globe, concentrating on locations far removed from the distorting effects of the past massive ice sheets.
Using an extensive series of sophisticated statistical tests, they then reconstructed sea-level history of the last 21 thousand years with a high degree of statistical confidence.
Their analyses indicate that the gradual rise at an average rate of 1 metre per century was interrupted by two periods with rates of rise up to 2.5 metres per century, between 15 and 13 thousand years ago, and between 11 and 9 thousand years ago.
The first of these jumps in the amount of ice-sheet meltwater entering the world ocean coincides with the beginning of a period of global climate warming called the Bølling-Allerød period. The second jump appears to have happened shortly after the end the ‘big freeze’ called the Younger Dryas that brought the Bølling-Allerød period to an abrupt end.
“Our estimates of rates of sea-level rise are lower than those estimated from individual study sites, but they are statistically robust and therefore greatly improve our understanding of loss of ice volume due to the melting of the ice sheets at the end of the last Ice Age,” said lead author Dr Jennifer Stanford of SOES.
“The new findings will be used to refine models of the Earth climate system, and will thus help to improve forecasts of future sea-level responses to global climate change,” added Rohling.
The researchers are Jenny Stanford, Rebecca Hemingway, Eelco Rohling and Martin Medina-Elizalde (SOES), Peter Challenor (NOC) and Adrian Lester (The Chamber of Shipping, London).
The research was supported by the United Kingdom’s Natural Environment Research Council.
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The new findings will be used to refine models of the Earth climate system, and will thus help to improve forecasts of future sea-level responses to global climate change,” added Rohling.
OR…natural sea level rise will be used in “models” to predict Human caused sea level rise???
or am I missing something
This is known for decades!
A good discovery would be to say where Atlantida was…
Nonetheless, it is important that alarmists know there was far bigger sea level rise in the past!
And I as have commented before here, it should be from the CO2 from our far ancestors’ fireplaces. Or maybe from the mammoths methane? Or something in between…
Ecotretas
Um, 1.5 mm per annum x 100 = 150mm = about 6 inches by 2110, if the linear rate were to be maintained.
I’m not going to drown after all!!! Horray!
( I’m personally not at risk after 2050 at the extreme – have grandchildren tho’)
(and yes I know the catastrophic scenario of Greenland, land glacier and antarctic melting – but don’t believe it)
Ben Hillicoss says:
December 1, 2010 at 9:28 am
The implications are that ice sheets are unstable and prone to sudden collapse. One should not expect that sea level rise under global warming will be a constant x mm per year.
What can be said with certainty about sea level rise is that the rate of rise of the global mean sea level has DECLINED in recent years, as recorded by the University of Colorado at Boulder, from 3.2 mm per year to 3.1 mm per year. That change was quietly posted on their monthly publication of the data without, so far as I know, public announcement or fanfare (it isn’t the kind of news that draws more grant money). See:
http://sealevel.colorado.edu/
richard telford says:
December 1, 2010 at 10:05 am
Why should we assume that the remaining ice sheets are going to melt? Given the temp delta from the recent glacial period to today, and looking at the sigmoid curve of the sea level, why are you assuming the total melt of Greenland and/or Antarctica within a short time period?
WOW, and look at that rise since the end of the last ice age. Engineers have a description for the last few tens of meters … measurement error.
I have seen this graph a number of times and my eye is always drawn to the “Meltwater Pulse 1A”. Since there is no “Meltwater Pulse 1” and no “1B” can someone say why this called what it is? Why not drop the “1A’? Curious.
Come on Richard Telford!
Back at the end of the last ice age period.There were vast amounts of Ice overlaying North American and Siberian lands to melt off.Thus making it possible for large sea level increase to proceed when the melting sped up as part of the transition from an ice age to the current interglacial period we live in.
Today there are not much easy to melt glacial ice left,to be able to cause large increases in sea level rise.In fact it is nearly IMPOSSIBLE for sea level rise to accelerate to a much higher rate.Since there are so little easy to melt ice left to work with.
Really there are little left beside Greenland and Antarctica to melt away anymore.The vast North American Glacial ice cover overlaying land are ALL GONE,having melted away,to make the sea level rise over 100 meters higher.
The chart plainly shows that around 8,000 years ago.The melting rate and the sea level increase rate quickly leveled off to nearly a flat line.It has been that way ever since.
The easy to melt ice took around 10,000 to melt away.By 8,000 BC it was all gone. The reason why the sea level increase rate quickly flattened out to just above zero.
OT
I have my first body count of 8 people frozen to death so far in the 2010-2011 northern hemisphere winter season. We better get some of that global warming they speak of soon or this winter seasons body count will be larger than last years.
“Heavy snow and subzero temperatures swept across Europe, killing at least eight homeless people in Poland, closing major airports in Britain and Switzerland and causing hundreds of highway accidents.”
Heavy Snow Causes Severe Disruption in Europe
http://www.cnbc.com/id/40447815
P.S.
I’m not into eugenics so I really don’t find counting dead frozen bodies very funny. I just think it needs to be pointed out in a very ugly way so people at least ask the question, why is the count going up in recent years? Hint: It’s the sun stupid.
Ecotretas says:
December 1, 2010 at 9:38 am
“This is known for decades!
A good discovery would be to say where Atlantida was…
Nonetheless, it is important that alarmists know there was far bigger sea level rise in the past!
And I as have commented before here, it should be from the CO2 from our far ancestors’ fireplaces. Or maybe from the mammoths methane? Or something in between…
Ecotretas”
Maybe the Atlanteans were big consumers of fossil fuels? After all, they had a nice long ice age to develop their civilization, where we’ve only had this short interglacial. Oh yeah that’s right, their electromagnetic pyramid power-nodules caused the earth’s axis to slip, triggering the great flood and their own destruction. As you can tell, I delight in internet conspiracy theories. And I thought somewhere below the bermuda triangle was the heart of atlantis. That’s why planes and boats go missing there, the lingering electromagnetic interference from some forgotten antediluvian technology.
Wouldn’t it be nice if modern day scientists could just stick to explaining to us how things seem to be? Einstein told us that E=MC2. We believed him and were happy with that. He did not then take unto himself the role of prophet and tell us what would happen to M if we should carry on a pursuit of E instead of getting ourselves a horse. He knew the dangers of hypothetical extrapolation. He didn’t need to explain that, as Mark Twain had already taken good care of it.
RE: Southampton researchers have estimated that sea-level rose by an average of about 1 metre per century at the end of the last Ice Age, interrupted by rapid ‘jumps’ during which it rose by up to 2.5 metres per century.
It will have to rise a lot faster than that to keep up with Al Gore’s numbers. 😉
Ken Harvey says:
December 1, 2010 at 11:02 am
But, please, explain us, how is it that if the maximum velocity is that of light, he SQUARED IT?…that’s too much I guess.
[Please expect some corrections on this comment. Are you sure you want it to remain? 8<) Robt]
from the publication abstract:
“Even the use of the more ubiquitous mwp-1a in modelling studies has been compromised by debate about its exact age, based upon perceived discrepancies between far-field sea-level records. It is clear that an objective investigation is needed to determine to what level inferred similarities and/or discrepancies between the various deglacial sea-level records are statistically rigorous (or not). For that purpose, we present a Monte Carlo style statistical analysis to determine the highest-probability sea-level history from six key far-field deglacial sea-level records, which fully accounts for realistic methodological and chronological uncertainties in all these records, and which is robust with respect to removal of individual component datasets.”
“we present a Monte Carlo style statistical analysis” <– hmmm, what does this mean — flip a coin and you've got a 50:50 chance of being right?
richard telford says:
December 1, 2010 at 10:05 am (Edit)
Ben Hillicoss says:
December 1, 2010 at 9:28 am
The implications are that ice sheets are unstable and prone to sudden collapse. One should not expect that sea level rise under global warming will be a constant x mm per year.
—…—…—
Ah, but you are dead wrong. Yes, the earlier sea level rises (see spike 1A for example) were due to sudden losses of land-based ice masses. But, like the fools who talk about a reversal of the Gulf Stream due to melting Greenland ice caps, you are assuming the starting conditions for a mythical massive ice melt are the same as those conditions 14,000 years ago.
Today, unlike earlier geological eras, has NO 5000 foot-thick glaciers covering Chicago, Alberta, Manitoba, Montana, North Dakota, South Dakota, Idaho, and New England. There can be NO sudden rise in sea levels from melting ice today – because there is NO comparable ice present today. Thus there can be NO reversal of the Gulf Stream regardless of increasing temperatures. But that threat is still used in the CAGW propaganda.
Yes, we should project no century-long sea level increases 100 years into the future. BUT – today’s CAGW extremists project into the future a theoretical rise (that stopped increasing six years ago), but only after INCREASING that theoretical rise by 50%, THEN projecting that inflated rise for the next 400 years. Even the CAGW alarmists agree that Greenland’s ice cap would require 600 years to melt just half of its area, but we are given photo-shopped propaganda showing New York will be flooded by 20 meters in only 60 years.
The important thing is that today we are wise enough to know the correct sea level is the present level, and should never again be allowed to change. Kind of like the climate.
“Global sea level rose by a total of more than 120 metres as the vast ice sheets of the last Ice Age melted back. This melt-back lasted from about 19,000 to about 6,000 years ago, meaning that the average rate of sea-level rise was roughly 1 metre per century.”
Could this be the source of the “biblical flood” myths? Could be.
If you look at the graph from 16000 years ago to the present, it looks rather like a hockey stick standing on its handle. Maybe this one can replace MMs debunked stick.
[Please expect some corrections on this comment. Are you sure you want it to remain? 8<) Robt
It’s OK…how is it C sq.2 ? The first nuke would have blew up the whole Solar System 🙂
Planck was more conservative: E=hv
sunsettommy says: at 10:54 am
I agree with you. The easiest ice to melt has already been melted.
Here is an example of one of the many floods that caused the “jumps” in the sea level. There are not many of these events left to happen either.
The Missoula Floods (also known as the Spokane Floods or the Bretz Floods) refer to the cataclysmic floods that swept periodically across eastern Washington and down the Columbia River Gorge at the end of the last ice age.
http://en.wikipedia.org/wiki/Missoula_Floods
pwl says:
December 1, 2010 at 11:28 am . See:
Confirmation of the rapid freezing from paleomagnetism
http://daltonsminima.altervista.org/?p=12219
What effects would these sudden changes in weight distribution as the glaciers melted, have had on the earth’s balance, and thus it’s orbit?
OT: Sunspots number discrepancy: For the month ending at NOAA’s 36.1, while the office for the SN SIDC final stand at 22.2 …
http://daltonsminima.altervista.org/?p=12665
Before that amount of melt water entered the sea must have been very salty, how did all the sea creatures manage? It wasn’t man made so it was all right.
James