From Newcastle University
New understanding of Antarctic’s weight-loss
New data which more accurately measures the rate of ice-melt could help us better understand how Antarctica is changing in the light of global warming.
The rate of global sea level change is reasonably well-established but understanding the different sources of this rise is more challenging. Using re-calibrated scales that are able to ‘weigh’ ice sheets from space to a greater degree of accuracy than ever before, the international team led by Newcastle University, UK, has discovered that Antarctica overall is contributing much less to the substantial sea-level rise than originally thought.
Instead, the large amount of water flowing away from West Antarctica through ice-melt has been partly cancelled out by the volume of water falling onto the continent in the form of snow, suggesting some past studies have overestimated Antarctica’s contribution to fast-rising sea levels.
Using Gravity Recovery and Climate Experiment (GRACE) satellite data, the team calculated ice sheet mass loss by more accurately mapping and removing the mass changes caused by the flow of rock beneath Earth’s surface.
Publishing their findings today in the academic journal Nature, project lead Professor Matt King said the data meant we were at last close to understanding how Antarctica is changing.
“We have tried to weigh the ice in the past but GRACE only measures the combined effect of the ice changes and the land mass changes occurring beneath the Earth’s surface,” explains Professor King, Professor of Polar Geodesy at Newcastle University. “The step forward we have made is to provide a better calculation of the land mass changes so we can correct the satellite measurements to more accurately calculate the changes in ice mass alone.
“Our ice change calculations rely heavily on how well we can account for these important changes taking place beneath the Earth’s surface. While the land beneath the ice is moving by no more than a few millimetres-per-year – the thickness of a fingernail –that seemingly small effect significantly alters the rate at which we estimate the ice is changing.
“By producing a new estimate of the land motion we’re effectively re-calibrating the scales – in this case the GRACE satellite –so we can more accurately weigh the ice. And what we’ve found is that present sea level rise is happening with apparently very little contribution from Antarctica as a whole.”
Because most of the Antarctic land surface is covered by ice it has been incredibly difficult to determine where it is rising and falling and by how much. That has meant GRACE data hasn’t been able to contribute as much as it could to help scientists understand if Antarctica was growing or shrinking.
“We’re now confident it is shrinking,” says Professor King, currently on secondment at the University of Tasmania, Australia. “Our new estimate of land motion helps us narrow the range and shifts the best estimate to the lower end of the ice melt spectrum.
“Worryingly, though, the rate of shrinking has sped up in some important locations. The parts of Antarctica that are losing mass most rapidly are seeing accelerated mass loss and this acceleration could continue well into the future.”
“The sea level change we’re seeing today is happening faster than it has for centuries with just a small contribution from the massive Antarctic ice sheet. What is sobering is that sea levels will rise even faster if Antarctica continues to lose increasingly more ice into the oceans.”
The research is part of a £600,000 project funded by the Natural Environment Research Council (NERC) to investigate the changing mass of the Antarctic Ice Sheet.
Ice sitting on the Antarctic continent at the peak of the last ice age 20,000 years ago forced the rock beneath to deform and slowly flow away. After that time ice levels generally reduced and the rock within the Earth’s mantle more than 100km below the surface has been slowly flowing back in. That change affects the GRACE satellites in exactly the same way as ice moving into and out of the continent.
Since their launch in 2002, the GRACE satellites allow scientists to map Earth’s gravity field every 30 days, mapping changes as mass moves around the Earth’s surface as well as below it.
Newcastle University’s Dr Rory Bingham adds: “There are lots of measurements that tell us something about the recent state of the Antarctic Ice Sheet, but none of those measurements gives the complete picture.
“This research starts to pull that picture together, providing the most accurate GRACE estimate so far of Antarctica’s contribution to sea level as a whole, as well as identifying which regions are changing and which are not.
Professor Mike Bentley, of Durham University, UK, who was part of the project team said, “This project brought together a range of scientists including geologists, geodesists and computer modellers to work out the contribution of the Antarctic ice sheets to global sea level rise. We have shown that the Antarctic contribution is smaller than some previous estimates, but the ice sheet is changing very rapidly in some key regions”.
From The Age in Australia, it seems that there are some good points, namely about sea level rise:
=============================================================
Although parts of East Antarctica are growing, glaciers in West Antarctica are melting faster, leading to a net loss of ice across the continent, according to a study published in the journal Nature.
”We’re confident that the ice cover is shrinking, and the rate along the Amundsen Sea coast is accelerating,” said Professor Matt King, of the University of Tasmania.
One result of the findings is that melting ice in Antarctica is not contributing as much to a rise in global sea levels as some other studies have assumed.
…
‘The melt in some key areas is sped up between 2006 and 2010, when the study ended,” he said. ”So it shows that sea level rise can be expected to change quite sharply if the melt rate continues to increase, on top of what’s already happening.”
===============================================================
Still, all this is hard to reconcile with the sea ice graph from Antarctica showign a growing trend over the period of the satellite record since 1979:
Cryosphere Today – Arctic Climate Research at the University of Illinois – Click the pic to view at source
and now for some rationalisation:
22 Oct: Toronto Star: Raveena Aulakh: Antarctic sea ice is increasing — is global warming over?
Not at all, say climatologists.
The Antarctic is land covered with ice and surrounded by water; the Arctic is water surrounded by land. “That makes them hugely different and how climate change affects them is also different,” said Gordon McBean, director of research at the University of Western Ontario’s Centre for Environment and Sustainability.
“In the Antarctic, there is ice in the centre and as it meets with ocean, currents lift it a bit,” said McBean. “It can result in more sea ice.”…
Scientists say there is also the issue of depletion of ozone in the stratosphere in the Antarctic, which makes the stratosphere even colder, preventing ice from melting.
But McBean says while the Antarctic is still cooler than the rest of the world, it is also warming up. “Just not as quickly,” he said.
The phenomenon in the Antarctic is not inconsistent with global warming, said McBean. “It was expected . . . it’s a complex situation.”…
But the growing sea ice in the Antarctic will have not have an impact on sea level, said Jing Chen, professor with the department of geography at the University of Toronto…
“We should not be too complacent about the recent ice increase,” he said. “If (global) warming keeps increasing, it pushes average temperatures above freezing points and the Antarctic area ice will decrease and the trend will quickly reverse.”
Growing sea ice in the Antarctic is good news “but (we) have to take it in the right perspective: it will not increase forever.”
http://www.thestar.com/news/world/article/1275441–antarctic-sea-ice-is-increasing-is-global-warming-over
So let me get this straight. The GRACE satellite has been in orbit since 2002. And through their “new and improved” guesses on what’s happening to the ground under the ice sheets, these scientist are able to state that the current ice loss is the greatest in centuries. All that from 10 years of data and new guess work.
I feel so much better now about the science. /sarc
Remind me where the sea level rise is actually occurring? Satellite measurements show tapering off/slight decline…
Quote: …” Antarctica overall is contributing much less to the substantial sea-level rise than originally thought” Who says the sea level rise is substantial? At its present rate (3.1 mm/yr) sea level will rise by 8 inches in 100 years..not substantial in my opinion. These guys always have to put in some alarmist tripe
Can someone please remind me how “substantial” the current rate of sea-level rise is? I thought I’d seen a figure of 3.5mm/yr? So that would be 350mm/century, which I understand is what happened in the 20th century and we seem to have survived.
Erm, what “substantial sea-level rise” are they talking about?
Erm, what “substantial sea-level rise” are they talking about?
“The rate of global sea level change is reasonably well-established…”
By whose standards?
From what I read, the rate of sea level change is largely the summation of several poorly educated guesses about the amount of crust rebound, ice melt and who knows what else.
Also…we have ice in plan sight, but the adjustment in this study was made on millimeter shifts in the Earth’s crust, for which we have no direct measurement. From that, they make assumptions about the ice, which we can directly measure, and find to be increasing overall.
Except in some areas, and those areas are worse than we expected, signalling the potential for a really rapid rise in sea level when CAGW really kicks in… which will be soon, although we haven’t really seen any evidence of it happening at all, so far.
So in summation…the news is better than we thought, but worse than we expected.
(If we paid them another 600,000 pounds, do you think they would make a little more sense?)
[1] “Instead, the large amount of water flowing away from West Antarctica through ice-melt has been partly cancelled out by the volume of water falling onto the continent in the form of snow, ”
I thought Antarctica was supposed to be a desert? I assume that the amount of water flowing away is not insignificant which means that the amount falling on the continent is not insignificant. I think because the driest place on the planet is on Antarctica it suits certain narratives to make all of Antarctica a desert. The explanation given for why Antarctica’s Dry Valleys have seen no rain for 2 million years is because “The unique conditions in the Dry Valleys are caused, in part, by katabatic winds; these occur when cold, dense air is pulled downhill by the force of gravity. The winds can reach speeds of 320 kilometres per hour (200 mph), heating as they descend, and evaporating all water, ice and snow.”. http://en.wikipedia.org/wiki/McMurdo_Dry_Valleys#cite_note-2
[2] “The sea level change we’re seeing today is happening faster than it has for centuries with just a small contribution from the massive Antarctic ice sheet. What is sobering is that sea levels will rise even faster if Antarctica continues to lose increasingly more ice into the oceans.”
There must be uncertainty in this assumption as increasing ice loss could be an indication of increasing precipitation and therefore increased weight of ice pushing down, just as increased rainfall means increased river flow. This could be an indication of increasing temperatures but I don’t know how that translates to an area that experiences temperatures tens of degrees below freezing anyway, if for example it’s -19 instead of -20, or -88.2 instead of -89.2 (http://en.wikipedia.org/wiki/Lowest_temperature_recorded_on_Earth)
Hands up all those who suspect the changes in land-based Antarctic ice mass are purely natural and beyond human influence.
I often see this gobble-de-gook catch 22 garbage:
——————————-
“The sea level change we’re seeing today is happening faster than it has for centuries with just a small contribution from the massive Antarctic ice sheet. What is sobering is that sea levels will rise even faster if Antarctica continues to lose increasingly more ice into the oceans.”
The research is part of a £600,000 project funded by the Natural Environment Research Council (NERC) to investigate the changing mass of the Antarctic Ice Sheet.
——————————-
it’s fast, no it’s not, it’s small, maybe not, what if it gets bigger and faster, give me more money….
Cut off the funding.
These so-called satellite measurements always have to be based on some fairly crude MODEL of how the underlying rock is moving. At least this article seems pretty honest about the problem. At the end of the day this comes down to guessing the “viscosity” of rock.
GRACE is pretty impressive. Guesses of viscosity less so. It seems the latest guess is an improvement on earlier guesses.
The recent change they have picked up may reflect the recent change in length of melting season. As I recently pointed out in discussions of Arctic melting we again see the polar see-saw in operation. Arctic has seen its melting season shorten , Antarctic lengthen.
http://i50.tinypic.com/2mdgitw.png
The big difference is that while Arctic has passed the bar of 6 months and now has freesing season longer than melting , Antarctic is still well below 6 months. This is coherent with the continued increase in ice extent down under.
My guess is that the next guess will find even less “apparent” ice loss.
Claims that sea levels are still rising depend on equally uncertain estimates of how much land is moving and how much GAIA adjustment can be added to the REAL sea level to account for deepening of the ocean basins.
Fortunately all this is unverifiable so they can make the guesses and models fit political needs of the day.
Snow – who would have thought it. Apparently it weighs something.
This was so full of obligitory alarmist nonsense all leading down to the bottom line of: “gimme some more grant money” that I had difficulty in finishing it.
“Antarctic weight loss seems to be in the eye of the beholder”
“Does this glacier make me look fat?”
I’ve been puzzling over this. Are our measurements really that good yet? Early posts upthread have already pointed out many uncertainties. An error of a few cubic kilometers here and there and pretty soon you’re talking all educated WAGs.
Perhaps this is yet another Global Warming Paradox:
Just like the warming causes warm snow,
accelerated melting might actually cause sea level drooping.
You just have to Believe in the new nonsense science.
Sea level changing rapidly? I don’t buy it. What sea level change?
Take a look at this mean sea level mark carved in the stone on the `Isle of the Dead’ in Tasmania by Capt. Sir James Clark Ross in 1841. The tidal range there is but one meter and the photo is at low tide.
http://www.john-daly.com/photomrk.htm
http://www.john-daly.com/index.htm
a few millimetres-per-year – the thickness of a fingernail
I think there is medication available to treat this condition. /sarc
The average thickness of fingernails for males is 0.384 mm
and for females is 0.346 mm [by Testut quoted in ICRP 23, 1975]
http://health.phys.iit.edu/extended_archive/0003/msg00465.html
“The research is part of a £600,000 project funded by the Natural Environment Research Council (NERC) to investigate the changing mass of the Antarctic Ice Sheet.”
I wonder what the report would have found if the research wass part of a £600,000 project funded by the Natural Environment Research Council (NERC) to investigate the unchanging mass of the Antarctic Ice Sheet.
You get what you pay for.
GRACE is rubbish.
It measures gravity pretty well but it has no idea what causes the local change in gravity. Hence the models. Technique:
1. Decide what you want the answer to be
2. Use model to separate the various possible causes of change in local gravity
3.
FudgeTune model to produce desired answerAny questions?
“…by no more than a few millimetres-per-year – the thickness of a fingernail…”
Which part of the Neanderthal Valley are these folks from?
Gotta love it. Our models that predicted ice loss in the antarctic have turned out to be completely wrong, but if all the things that made them wrong change in some way to make them right again, it could be very very bad, so we were possibly right in the first place and it could be worse than we thought.
We also took several pictures of swimming polar bears and concluded that their noses are less than 8 inches above the sea surface, so if sea levels continue to rise, over the next 100 years all the polar bears will drown.
This story reflects a serious problem regarding the use of GRACE data – but at least it finally honest about it. If you look at the amount of mass associated with ice from a GRACE measurement, you quickly realize people are jumping massive chasms of ignorance to reach their conclusions. GRACE measure total gravity anomalies. That means it measures the total mass under the satellites at some grid size. The assumption exposed here is:
“We have tried to weigh the ice in the past but GRACE only measures the combined effect of the ice changes and the land mass changes occurring beneath the Earth’s surface,”
Now they like to claim this is only the crustal mass, because the assumption is only the crust mass changes over time. But this is a ridiculous rush to judgement. If the core, mantle, etc are semi-fluid and not 100% consistent composition (which is silly to assume), then changes in the density integrated from the center out to the crust along the measured surface grid would dominate the changes seen in GRACE product. It is the ice that is a sliver of hair upon this mass of crust, molten rock and liquid iron. And there is NO WAY to tease that signal out of GRACE data knowing so little about the composition and dynamics of the interior of our planet.
“What is sobering is that
sea levels will rise even faster if Antarctica continues to lose increasingly more ice into the oceanswe’ve blown through almost all of the £600,000 and the last keg is almost empty.”There, fixed that for ‘ya.
“Still, all this is hard to reconcile with the sea ice graph from Antarctica showign a growing trend over the period of the satellite record since 1979:”
Well if you look at the rate of change of ice area there are positive and negative changes.
http://i48.tinypic.com/25z1aaf.png
This can be seen in the plot at the end of the article. There are many times when , short term, there’s a loss and even recently when the anomaly goes briefly negative.
So all you need to do , to keep in line with the politics, is focus on _some_ areas at some times and start to play the “if this continues… OMG” game in order to ensure you’re on side.
Of course looking at all the data is usually the best idea. The data in the last plot of the article is pretty clear once a little low pass filtering is applied.
http://i46.tinypic.com/dn1q43.png
Volume is ultimately the what we need to be looking at not area which could be deceptive in either direction. However, last time I saw uncertainty figures it was like X billion cubic km -0/+100% , ie between something really big and… nothing at all.
All this work is valuable progress but it really is not ready to start making “if it continues” type projections.
Best stick with area observations for a while I think.
Johanus says:
October 22, 2012 at 1:57 pm
“…by no more than a few millimetres-per-year – the thickness of a fingernail…”
Which part of the Neanderthal Valley are these folks from?
Brilliant. Had me chuckling that one. I thought the fingernail bit was pretty stupid but the Neanderthal bit is a blast.
‘The melt in some key areas is sped up between 2006 and 2010, when the study ended,” he said.
OK, they show melting so they must be “key areas” , right? Did they also smell of cherries by any chance?
Are we to believe that the end of the study means this is best, most representative period to talk about? Of course not. But if it smells of cherries , it must be sweet.
”So it shows that sea level rise can be expected to change quite sharply [b]IF[/b] the melt rate continues to increase, on top of what’s already happening.”
In view of the oscillatory nature of the changes, is there anything remotely scientific or believable about the big IF ? Not at all. And any scientist who has that kind of mileage knows it damn well.
Ok so they got their grants for next year and the beer money and , hell, a nice little overseas contract in Tassie. Lovely place.
An’ who cares if they have to misrepresent the truth a bit , it’s to help save the planet after all.
I look forward to their millimeter perfect maps of snow, ice, underlying crust and mantle.
Jay Zwally of NASA GSFC found that Antarctica gained terrestrial ice by about 49 km^3/year from 2003 to 2008. Dr Zwally is not a sceptic having predicted a nearly ice free Arctic this year.
So translating from climateer-speak: “Antarctica overall contributing much less to the substantial sea-level rise than originally thought” means “its actually contributing a sea level fall but we’re too embarassed to say this”.
What do we know about the density of the mantel, and disparate heat flow within the mantle which it appears could also affect grace?
The newest IceSat recalibrated measurements for Antarctica are a net mass increase (new corrections from the large network of GPS monitoring stations now in place indicating a certain rate of uplift left-over from the last ice age versus the previous estimates).
http://wattsupwiththat.com/2012/09/10/icesat-data-shows-mass-gains-of-the-antarctic-ice-sheet-exceed-losses/
Grace has now has been corrected for the same effect and it now has a much lower mass loss than previously estimated while Icesat has a positive mass increase. (a different related study linked below).
http://www.the-cryosphere-discuss.net/6/3703/2012/tcd-6-3703-2012.pdf
No net loss in Antarctica would be the conclusion averaging all three estimates. They haven’t fully corrected the Greenland numbers yet but it does mean that the sea level increases must be far off the mark now.
And we know they have been adjusting the sea level numbers based on what was assumed from ice-sheet loss from Antarctica and Greenland.
Tangled web was previously weaved and now everything will have to be rewritten.
Bill Illis says:
October 22, 2012 at 5:43 pm
[in part]
“And we know they have been adjusting the sea level numbers based on what was assumed from ice-sheet loss from Antarctica and Greenland.”
I’ve been reading WUWT for quite some time now and I don’t recall running across that information in the sea level discussions. Just more of the same ol’ same ol’ “adjustments” it seems.
Thanks for that tidbit.
P. Solar says:
October 22, 2012 at 1:10 pm
The recent change they have picked up may reflect the recent change in length of melting season. As I recently pointed out in discussions of Arctic melting we again see the polar see-saw in operation. Arctic has seen its melting season shorten , Antarctic lengthen.
http://i50.tinypic.com/2mdgitw.png
While the Antarctic sea ice maximum gets the attention, the Antarctic sea ice minimum has been increasing more, especially in years when Arctic sea ice hit record minimums
Decreased cloud cover is the common cause, because of much higher levels of black carbon in the Arctic.
http://earthobservatory.nasa.gov/Features/WorldOfChange/sea_ice_south.php
Bill Illis,
Once again, thanks sincerely for your contributions here.
You are for sure one of the most sensible contributors gracing WUWT.
Confidence is far more important than skill in the gruelling field of climate-catasprophe.
“Brian R says:
October 22, 2012 at 12:20 pm
So let me get this straight. The GRACE satellite has been in orbit since 2002. And through their “new and improved” guesses on what’s happening to the ground under the ice sheets, these scientist are able to state that the current ice loss is the greatest in centuries. All that from 10 years of data and new guess work.
I feel so much better now about the science. /sarc”
It doesn’t sound to me like you got it straight, because the article never said the current ice loss is the greatest in centuries and I’m not being sarcastic. The article mentioned sea level change being more than they’ve seen in centuries.
How much does silt runoff into the oceans effect the sea level? For that matter aquifer drainage and other assorted sources of water. We are always being hit by GCRs which are supposed to make more cloud cover and precipitation.
“The phenomenon in the Antarctic is not inconsistent with global warming, said McBean. “It was expected . . . it’s a complex situation.”
—————-
Is it just me, or have others noticed that these various ‘as expected’ occurrences are never predicted publicly before they occur?
So, the Antarctic ice has been steadily increasing for at least three decades, yet it’s still contributing to allegedly rapid sea-level increase. How does that work, then? Where’s all the extra water coming from?
Philip Bradley says:
>>
While the Antarctic sea ice maximum gets the attention, the Antarctic sea ice minimum has been increasing more, especially in years when Arctic sea ice hit record minimums
>>
Indeed the obsession with either extreme, plucking one day out of the year is a very poor and unscientific way of assessing what is happening. That is why I used a gaussian filter that takes data from 6 weeks either side to calculate the dates of min and max when assessing the length of melting periods posted above.
Also my plots of ice area/extent use 365(6) days per year of data, not one.
http://i47.tinypic.com/72zrio.png
There has been a steady underlying increase Antarctic sea ice area since 1985 that does not get much press. Another interesting feature is that since the big slide in Arctic ice cover ended in 2007 the short term variations seem to be in phase at the two poles in net contrast to the earlier oscillations that were out of phase.
As I’ve discussed in other threads, the Arctic melting seems to be an adjustment to the warmer AMO Altantic SST . Since AMO reached the peak of its 60y pseudo cycle the accelerating melting ended.
It seems all of this is irrelevant to some who won’t be happy until glaciers stop sliding down hill.
Oops, missed off the second graph:
http://i46.tinypic.com/r7uets.png
Bill Innis says: “And we know they have been adjusting the sea level numbers based on what was assumed from ice-sheet loss from Antarctica and Greenland.
Tangled web was previously weaved and now everything will have to be rewritten.”
Yes, what Colorado U. call Mean Sea Level has little to do with level of the sea any more. It is some kind of “estimated global warming from sea level index”. If they want to do that, they should clearly label it as such and not misrepresent it as “mean sea level”. It is not.
One of the main reasons people are concerned with sea level is that they may get wet. This fictitious sea level misrepresents that risk and should be labelled for what it is and the true sea level also made available in an equally visible and accessible way.
Unfortunately this is yet another valuable dataset that had been hijacked for political ends.
Previous ice loss was much, much higher than GCMs had expected. This sounds like it brings the observations closer to the models.
http://i46.tinypic.com/303ipeo.png
+
http://i49.tinypic.com/wwdwy8.png
=
http://i48.tinypic.com/2v14sc5.gif
(slow animation of preceding pair)
A 3-century-old modeling assumption – which is supported by not so much as a single observation – has been overthrown.
Amazing, isn’t it? I thought they had just got finished showing that global warming meant a colder antarctica and now these guys come along and say it’s warmer?
There is a relationship between global warming and water. If someone with lots of time on their hands did some calculations the polar melt is easy to explain. We are taking water out of the evaporation system at an ever increasing rate. Greenhouse gasses causing global warming is a big furfy. Global warming is being caused by water storage. We have bottled water, beer, soft drinks, soup, back yard tanks, underground pipes in every town and city. Humans have a fetish for storing liquid in a myriad of forms. The polar melt is the climate trying to replace the liquid we have taken out of the system and stored. Sea rise is the ocean expanding due to global temperature rise. The more the sea rises the larger the surface area available to evaporation. Evaporation is water molecules reaching boiling point. Lots of evaporation means lots of water molecules generating heat. The “natural steam” is what is warming the planet. Give the water back to the system and the warming reverses. Historically global warming episodes have resulted from water being locked out of the system except this time its man who has taken the water.
Here is the Envisat satellite sea level numbers before and after processing ( 0.5 mms/yr Raw versus 2.6 mms/year Processed) [note satellite communications were lost at the end of March 2012 so this chart is the latest processed estimates from the satellite’s operators ESA].
http://s17.postimage.org/94jqjrubz/Envisat_Corrections.jpg
Well how do you decide how much processing is required? There is satellite drift, and instrument corrections but there are also models of how much it is “supposed” to be.
It is supposed to be at least 2.5 mms/year based on 1.0 mm/year of thermosteric ocean heat content rise (which itself is a high number based on the newest OHC data but nonetheless) …
… and between 1.0 to 1.5 mms/year from Glacial Ice Melt. And the Glacial Ice Melt numbers are based on mass losses of -200 billion tons per year from Antarctica on the high side (which we now know is only +48 to -102 billion tons per year) and -200 billion tons per year from Greenland (so far uncorrected for the new GIA models).
http://s15.postimage.org/snr31hhln/Sea_Level_Contributions_Meyssignac2012.jpg
Antarctic contribution to sea level rise is 0.5 mms/year at a mass loss of -200 billion tons per year (now +48 to -103 billion tons).
http://s13.postimage.org/a5jipj9s7/Antarctic_Sea_Level_Contribution.png
I am a New Zealander working in Europe for the past 14 years, anyone who wants to comment on sea-level rise and has not flown or sailed from Europe to NZ is talking out of the wrong end !
“The rate of global sea level change is reasonably well-established …”
The operative word is “reasonably”.
“Global warming is being caused by water storage. We have bottled water, beer, soft drinks, soup, back yard tanks, underground pipes in every town and city. Humans have a fetish for storing liquid in a myriad of forms. The polar melt is the climate trying to replace the liquid we have taken out of the system and stored..”
Croovy69,
Are you sure you didn’t pinch that comment from the Onion?
These guys seem to need help drafting up their reports: I’ve summarized it for them:
1. Grace measuring gravity seemed like a good idea, and a great way to measure ice loss, but much to our surprise it turned out that we can’t tell the difference in ice going and rock moving in.
2. When we discovered that we modelled it again, but to make the numbers work we had to lower our estimates of how much ice the Antarctic is losing.
3. That leaves a problem because we can’t account for the sea level rise others have been claiming.
4. However, we must finish this statement by saying that we think the ice loss rate of Antarctica will speed up in the future, then we will say we knew it all along.
5. If point 4 does not work out, we will revert to point 2, and model it all again.
If I empty my ice cube trays into the sink wonder how long it will take to melt down the drain hole.
Where can I apply for a grant, as I think this would be interesting to know ?
How many schizophrenic “scientific” reports do we have to suffer thru?
It isn’t as bad as we thought but it is worse than expected?
Antarctic ice is shrinking and contributing to known (and dangerous) sea level change… but Sea Level Rise is on a near straight line since the end of the Little Ice Age…. And really isn’t that bad….
This insults the intelligence of even the minimally intelligent.
“Australia’s Antarctic supply ship Aurora Australis is stuck in ice near Casey Station. The Antarctic Division’s operations manager, Robb Clifton, says it is not a problem at this stage with scientists out on the ice doing research work as normal.”
http://www.eureferendum.com/blogview.aspx?blogno=83261
Not sure what got that from onion means? Simply an observation that the graphs showing the increase in c02 since the industrial revolution would look similar if you replaced c02 with water storage. As well as pumping c02 into the atmosphere we have also been taking water out of a closed loop system. If the climate computer models were modified to take water storage into consideration we might start to get some answers that match what is actually happening. If warming is due to greenhouse the effect should be greater than what we currently observe.
jack mosevich says:
October 22, 2012 at 12:48 pm
Quote: …” Antarctica overall is contributing much less to the substantial sea-level rise than originally thought” Who says the sea level rise is substantial? At its present rate (3.1 mm/yr) sea level will rise by 8 inches in 100 years..
The accelerated sea-level rise (3.1 mm/yr) always gives me a giggle…
It was interesting to learn that the 18 cm sea level rise in the 20th century is actually a number supported by a model, it was very nicely explained by the deceased John Daly here:
http://www.john-daly.com/ges/msl-rept.htm
Since 1993 we have satellite record. The first results one can see still on Daly’s page. This record covers also the 1998 el nino which arises like a peak – under the title The Poseidon Adventure. There one can see for 1993-2000 period covered by satellite +0.9 mm/year
In 2003 this changes and the trend from the previous:
http://www.science-skeptical.de/wp-content/uploads/2012/04/Menard-2000.gif
becomes:
http://www.science-skeptical.de/wp-content/uploads/2012/04/Aviso-2003.jpg
so that it results in 2.3 mm/year (for 1993-2003)
In 2004 the rise was with the change to Jason1 3.0 mm/year for (1993-2004)
http://wattsupwiththat.files.wordpress.com/2009/04/uc_seallevel_2004r3.png
from 2004 to 2005 the sea level is stationary, however the total result is 3.1 mm/year – of course for the whole period!
http://wattsupwiththat.files.wordpress.com/2009/04/uc_seallevel_2005r5.png
Interesting to look here again at the 2004-2005 years in the 2006 chart:
http://wattsupwiththat.files.wordpress.com/2009/04/uc_seallevel_2006r3.png
but nevertheless we get already 3.2 in 2006 (for 1993-2006 period!) and a nice spike at the end
Now what is interesting is the 2007 one, it is again a big step. At first view there is nothing spectacular to the 2007 when one looks at the graph the respective year, it is the same height as 2006 but the rate overall jumped to 3.5 mm/year! (3.5 for the whole period 1993-2007)
http://wattsupwiththat.files.wordpress.com/2009/04/uc_seallevel_2007r2-1.png
If one watches the dark line in the 2007 chart and compare it with the 2006 chart one will see that it goes somewhere lower between the green points but it is still steeper then 2006!
At first sight the 2 look close, but the green points relative to the elevation do not fit any more.
In 2008 continues with no rise, actually all 3 years 2006-2008 there was no rise. Rate goes down to 3.3:
http://wattsupwiththat.files.wordpress.com/2009/04/uc_seallevel_2008r4.png
In 2009 it continues the trend with no actual rise, and the overall trend goes to 3.2 mm/year:
http://ecotretas.blogspot.co.at/2009/04/subida-descer.html
In 2010 the trend goes further down to 3.1 mm/year (1993-2010)
http://ecotretas.blogspot.co.at/2010/10/going-down.html
The next update takes very long. At this moment the sea is not rising or stationary but sinking, so we learned from NASA that 6 mm of world sea rained in Australia:
http://wattsupwiththat.com/2011/08/24/nasa-notes-sea-level-is-falling-in-press-release-but-calls-it-a-pothole-on-road-to-higher-seas/
Finally the numbers come with a bonus surprise, the rise is now 3.2 mm with an additional 0.3 GIA adjustment per year retroactively for the whole period 1993-2011 – so as per the “old” measurement would be 2.9 mm/year for the 1993-2011 inclusive the other adjustments.
In 2012 we see stationary, very slow rise, the rise is now down to 3.1 mm for the whole period. (actually 2.8 mm/year as of old…)
http://sealevel.colorado.edu/content/2012rel4-global-mean-sea-level-time-series-seasonal-signals-retained
Some of the satellite adjustments are shown here:
http://suyts.wordpress.com/2012/04/10/sea-level-rises-to-new-lows/
http://jeremyshiers.com/blog/sea-levels-still-rising-and-envisat-records-altered-to-show-this/
here in german:
http://www.science-skeptical.de/blog/was-nicht-passt-wird-passend-gemacht-esa-korigiert-daten-zum-meeresspiegel/007386/
And finally Frank does a recomputation here:
http://joannenova.com.au/2012/05/man-made-sea-level-rises-are-due-to-global-adjustments/
AUSTRALIA’S $46 million Antarctic airstrip is melting, leaving the government scrambling to find a new air link to the frozen continent.
The Wilkins runway — carved into ice near Casey station, about 3400 kilometres south-west of Hobart — was commissioned under the Howard government and hailed at its 2008 opening by then Environment Minister Peter Garrett.
But unexpected surface melt has sharply curtailed use of the summer-time airstrip.
http://www.theage.com.au/national/frozen-46m-runway-melting-20121023-283nk.html
Wilkins runway 66° 41′ 27″ S, 111° 31′ 25″ E
http://toolserver.org/~geohack/geohack.php?pagename=Wilkins_Runway¶ms=66_41_27_S_111_31_25_E_type:airport_region:AU
you can find it on Google Earth
A polar circle is either the Arctic Circle or the Antarctic Circle. On Earth, the Arctic Circle is located at a latitude of 66° 33′ 44″ N, and the Antarctic Circle is located at a latitude of 66° 33′ 44″ S
http://en.wikipedia.org/wiki/Polar_circle
66° 33′ 44″ Antarctic Circle
66° 41′ 27″ Wilkins runway
http://en.wikipedia.org/wiki/File:Polarkreis_-_zwischen_Narvik_%26_Mo_i_Rana_Norwegen.JPG
You think someone with a brain thought of that spot to build a runway on the ice ? If the sun is warm enough in Norway to make plants grow don’t you think it is warm enough to melt the upper part of the runway on the Antarctic in summer ?
As many others noted, the repetition of “the substantial sea-level rise” bespeaks more an effort to sell a Big Lie than anything else.
It isn’t an Antarctic summer now and summer doesn’t even start for two months. Summer melts are usually after summer has started, there is a lag, just like here.
Has anyone pointed out the difference between antarcitic sea ice and an antarcitic ice sheet?
Let’s compare just a couple of differences! Antarctica has two ice sheets left over from the Ice Age, the EAIS and the WAIS.
Ask the normal person to describe the three most unusual things they know about Antarcitica as a continent and they’ll get one of them right and say it’s cold or it’s the coldest continent. I doubt they will say it’s the driest and windiest continent. Antarctica is 1.3 times the size of Europe a desert and if it gets precipitation, it usually along the coast. It also has strong katabatic winds along the coast that can reach hurricane speeds and it will just blow snow out to sea. The winds are generated at higher altitudes, because the interior of Antarctica is so cold it can freeze carbon dioxide to dry ice. Much of Antarctica has an elevation above two miles and much of the antarctic sea ice has an elevation of four inches.
Do you think most people know this is what Antarctica looks like without the ice?
http://upload.wikimedia.org/wikipedia/commons/thumb/b/b7/AntarcticBedrock.jpg/1024px-AntarcticBedrock.jpg
But unexpected surface melt has sharply curtailed use of the summer airstrip.
Planes deposit black carbon on an Antarctic airstrip and the surface melts. Well, surprise, surprise.
http://www.canberratimes.com.au/environment/climate-change/antarctic-airstrip-melting-away-20121023-283kx.html