Steve Bloom points out on a thread I had, oddly, hoped would be about Benin, that Tom Fuller is in Fuller bloom over at WUWT(*), accusing me again of being an alarmist, when I am merely alarmed about the state of the world (as described by Schellnhuber and Rockstrom and Foley). I truly wish I weren't. I truly wish those guys were wrong. I truly wish I were wrong. But Fuller is not pulling together a convincing story, even though he seems to think he is.Like Fuller, I am eager to find evidence for the incorrectness of my views, but unlike Fuller, I have a more deeply elaborated understanding, and consequently am a bit more skeptical and harder to convince of alternative hypotheses.
The present kerfuffle comes down, apparently, to Fuller's claims about the Antarctic ice balance. Since I know or am at one degree of separation of some of the more prominent and talented researchers in the field of the mass balance of the great ice sheets, it reasonably falls to me to follow up and try to tell the whole story.
Before I look into it any further, let me state what my current understanding is. We can test out whether it is correct, but this is where I start.
The balance of evidence in mt's brain
as of early September 2010,
on the subject of
THE MASS BALANCE OF THE ICE SHEETS
1) First of all, the equilibrium response to a 3 C warming is enormous. If we hit the (approximately known and likely by now unavoidable) 3 C threshhold, and at that point civilization has no more capacity to think in the long term as we do today, we are looking at sea level rise in the tens of meters. This means Greenland will substantially be melted down to the rock, the WAIS (**) will totally disappear, and a substantial fringe of West East Antarctica will probably also be bare. The primary evidence is the geological evidence of seas that deep in the previous interglacial approximately 100kA ago.
2) It is considered nearly certain that the ice sheets will NOT respond quickly enough for the tens of meters of sea level rise which we would eventually expect with a 3 C rise to happen in this century (whew!) or even this millennium. But we would expect that level eventually if CO2 stays elevated high above quaternary (the past 2,000,000 years) values.
3) Rather than having a single time constant, though, the disintegration of ice sheets has recently been determined to be dynamically complex and operating on numerous time scales.
(Understanding the concept of time scales is key to understanding paleoclimate and clymate dynamics. As an example common everyday occurrence in some places I used to live is frozen puddles. Cold climate folk know that a puddle exposed to cold develops a film of ice first, and eventually freezes all the way through. The amount of time for it to gain or lose the thin film of ice at the top is much shorter than the time it takes to freeze through. Whether you are discussing whether the ice is superficial (say because you care about reflected light) or frozen solid (say, for traffic safety) determines a time scale of interest when you look at the weather.)
4) An ice sheet is in mechanical balance between large scale gravitational forces causing it to splay out and various small scale stresses and strains causing the ice to "like to" stay put.
5) On large physical scales, ice is a very viscous fluid, whose viscosity is sensitive to temperature. So different parts of the ice sheet flow at different rates. At the weakest points in the geometry, outlet glaciers form, which amount to areas where there is a steady flow of ice into the sea, which is where icebergs form.
(Icebergs are very different from sea ice.)
6) In a stable climate, the glaciers and the accretion of ice on top of the ice sheets are in rough balance. However, we know that the behavior of individual glaciers can be episodic, and important ones can grind to a complete halt, or conversely, speed up a great deal.
7) Imagine a huge mound of frozen grape jelly on a picnic table in the sun on a hot Texas afternoon. It will take a long time for the jelly to turn completely runny, though we know that will be its ultimate fate. Most of the jelly is a foot thick, but near the edges of the table it slopes off steeply. A tiny bit of the edge of the table is visible.
We know it will eventually run off the table, but consider how it might starts off. As the jelly warms up, it gets a little softer, and it can no longer sustain the steep slope. So it starts to spread. And the bits of spread that fall off the edge of the table no longer offer their viscosity to help hold up the rest of the pile.
The bits that fall off the table are like icebergs.
Near term sea level rise is about the fact that increasing temperature causes a gravitational instability at the steep edges. As long as the temperature increases, the edge of the ice sheets gets further into disequilibrium, and the ice sheet will retreat in much the same way as a beach retreats under rising sea level, where a small change in forcing yields a large response because the system needs to find a new physical slope.
8) It is also the case that the tops of the ice sheets, as they warm and hence receive more moisture, will be accreting. It will take a very long time before that mechanical signal becomes significant at the edges where the action is. Meanwhile, the tops of the ice sheets can somewhat mitigate sea level rise. The tops of the ice sheets constitute a true mitigating feedback to sea level rise, and in the short run this effect may dominate.
9) Both physical reasoning and paleoclimate evidence indicate that warming ice sheets do shrink, though. You were expecting, maybe, the Easter Bunny? So in the long run that effect is swamped by the shrinking edges, which makes sense in a simple model because the size of the accreting area shrinks.
10) A fellow named Christian Schoof appears to have worked out the mechanism for abrupt sea level rise such as the 14 kA event when sea level rose some 15 meters in 400 years. The mechanism has to do with ice sheets that have compressed the land the lie on enough that their bases are below sea level. Only certain geometric configurations of the outlets of such ice sheets are possible. If an ice sheet melts back or surges forward from one of these configurations, it is likely to reconfigure rapidly. There is only one such conditionally configuration on a large scale on earth at present, in the Amundsen Bay off the West Antarctic Ice sheet. If it were to retreat behind a certain ridge, it would become mechanically unstable, and a process would begin whereby it would eventually destabilize an ice basin large enough to cause an abrupt sea level rise of approximately 2 m.
11) The mass balance of Antarctica as a whole swamps the events in this area now, so the GRACE instrument may not pick them up. But nobody knows how quickly the destabilization will occur once the ice sheet lets go of its sill in the Amundsen embayment, which as I understand it, it already has. Once it starts, a one-time and abrupt sea level rise of about 2 or 3 meters in a few decades is plausible.
12) As for the Antarctic ice balance itself, I was coincidentally just looking at this picture in the Copenhagen Diagnosis yesterday
Here we see various estimates of the Antarctic mass balance over the past fifteen years. This is strongly suggestive of a significant change over that period.
Here, by the way, are comparable estimates for the Greenland mass balance:
13) A press release just yesterday (!) amounted to a major correction to GRACE estimates of mass flux. This is apparently a correction for isostatic rebound. It is good news because it means our worst fears that might be gleaned form the above graphs may need reconsideration.Based on this principle, previous estimates for the Greenland ice cap calculated that the ice was melting at a rate of 230 gigatonnes a year (i.e. 230,000 billion kg). That would result in an average rise in global sea levels of around 0.75 mm a year. For West Antarctica, the estimate was 132 gigatonnes a year. However, it now turns out that these results were not properly corrected for glacial isostatic adjustment, the phenomenon that the Earth's crust rebounds as a result of the melting of the massive ice caps from the last major Ice Age around 20,000 years ago. These movements of the Earth's crust have to be incorporated in the calculations, since these vertical movements change the Earth's mass distribution and therefore also have an influence on the gravitational field.
The corrected figures are reported in a multi-author paper in the Nature Geoscience by Wu et al. Quoth Wu:
According to our estimates, mass losses between 2002 and 2008 in Greenland, Alaska/Yukon and West Antarctica are 104±23, 101±23 and 64±32 Gt yr−1, respectively. Our estimates of glacial isostatic adjustment indicate a large geocentre velocity of −0.72±0.06 mm yr−1 in the polar direction. We conclude that a significant revision of the present estimates of glacial isostatic adjustments and land–ocean water exchange is required.This is a significant correction, but it nevertheless remains the case that the mass flux is clearly negative from all major ice sources. Of course, there's little reason to expect that this won't eventually be the case. The question at hand is when, and the answer is already, but the GRACE satellites may be weighing in on the low side for the next question, which is how much.
14) There is a geoengineering project called ice911 which I believe is worth considering that may fix the ice sheet problem.
(*) - WUWT is jargon on both sides of the climo-blogo-fence for "Watts Up With That", a blog of the sort that one refers to with a "nofollow". Watts has articles of varying degrees of sophistication, with the common thread that most of them are deeply confused. This does not mean everything said on WUWT is false. It means that all points of view are welcome, which is to say, scientifically informed opinion is vastly outnumbered and openly mocked. Watts provides a real service by providing a window into what people actually are thinking. How our society sunk to such a gnarled tangle that politically significant numbers of nonscientists see scientists this way is a subject I take up often, but not this time. Suffice it to say that articles on WUWT are often a horrifying mashup of information and disinformation, and that most readers have no serious basis to tell one from the other.
(**) - WAIS: West Antarctic Ice Sheet
ABOUT FULLER'S WUWT PIECE
"It is hard to understand many of those who are convinced that climate change will destroy civilization."
That is a near-empty class. I consider myself among those who hope that climate change will not destroy civilization, and choose to act on that basis.
And according to some scientists working with GRACE measurements, Antarctica is losing ice. Not just the Western Antarctic Ice Sheet, which has been predicted to melt and succumb to mechanical pressure since the 1930s, but also the vastly larger ice sheet covering East Antarctica.
And sure enough, the ‘apocaholics’ are all over this, using it to reinforce their unrelenting drumbeat of doom-laden predictions of disastrous sea level rises.
But this is actually quite strange. According to climate change theory, ice should be increasing in Antarctica–the (very slight) increase in temperatures and the natural increase in precipitation should result in more snow over Antarctica which gets compressed into higher levels of ice. The same phenomenon is both predicted and observed in Greenland, by the way.
"Instead of using this as proof of global warming"huh??? Sorry, what does that even mean?
" Because this is observed data working against the principles of their theory"uh, nope, remember, there is a tradeoff, one which Fuller actually described himself
"But they cannot pass up the chance for a quick and easy headline that reinforces the ‘all disaster, only disaster, 24 hours a day’ routine."huh???
"Certainly all measurements before GRACE showed increasing ice in Antarctica, as they do today."There's Fuller's hat, providing us with anti-information again.
"My guess (I’m not a scientist and do not claim to know) is that there are still a few bugs to work out in how they are doing this."This turns out to be quite true and an amazingly well-timed guess.
"So the paper referred to by scare artists like Michael Tobis of Only In It For The Gold "a - I am not a "scare artist"
b - It was Fuller who raised this paper
"says the Eastern Antarctic has lost 57 billion tons a year–plus or minus 52 billion tons."
I only said that - 57 +/- 52 was a decrease. I do not know to which paper Fuller refers, and can't seem to track down the original where he raises it. Fuller's name-calling is one thing, to claim that I raised some paper in the conversation after he himself brought the figures to the table is something else. (I looked all over the place and can't spot the conversation where this even came up, but I'm pretty sure the numbers came from Fuller and completely sure I didn't come up with them.)
Not all measurements of ice mass balance are via GRACE, as is obvious from the long record of Greenland estimates. John Cook has a nice piece on this on Skeptical Science.
It is one thing for Fuller to get the science wrong. On quantitative arguments requiring a little subtlety, one assumes he knows no better. But he is here making misleading statements on events of which he was a part. This can't be written off just as intellectual hubris.
And then a repeat of the claim that seems to me totally at odds with the facts:
Other measurements, consistent with climate theory, have consistently shown the Antarctic gaining, not losing ice.
No. That is wrong. Say it twice and it's still wrong.
Fuller seems to believe in making up facts to tell a convenient story. I don't think this constitutes helping.
mt, don't bother to rake your memory about whether you brought up the paper by Chen or not. Fuller's post is a piece of art (emphasis added):
ReplyDeleteSo the paper referred to by scare artists like Michael Tobis of Only In It For The Gold says the Eastern Antarctic has lost 57 billion tons a year–plus or minus 52 billion tons.
Apart from the insult, he is never claiming that you actually referenced the paper. He claims it is others "like" you that do it. So he slurs you without even given any "evidence" to go by. Despicable.
It was indeed Fuller to bring up the 57Gt number in the comments to "fifteen years ago:
ReplyDeletehttp://initforthegold.blogspot.com/2010/09/fifteen-years-ago.html?showComment=1283558311963#c8003066385162445367
Here's the paper by Chen he is referring to
ftp://ftp.csr.utexas.edu/pub/ggfc/papers/ngeo694.pdf
The current paper by Bromwich and Nicolas, that Anthony slapped beneath Fuller's post, can be found here:
http://polarmet.osu.edu/PolarMet/PMGFulldocs/bromwich_nicolas_ngeo_2010.pdf
Tom Fuller believes he speaks for "everyman" when he posts. Maybe he is correct in that assumption which is quite sad.
ReplyDeleteI wonder if this post just elevates his status among those that think they are staking a "middle ground" where there really isn't? One either accepts the science or not. He claims to do so but his posts reveal otherwise - either through ignorance or his obvious suspicion that there is massive group think.
I think it might be a good idea when writing about Fuller that one always mentions the fact that he co-authored the Climategate book The CRUtape Letters with Mosher.
What profmandia said.
ReplyDeleteMT:
I think your tactic -- of treating inactivists with more credit than they're worth -- is doing the opposite of helping things. The only thing it accomplishes is (surprise, surprise) to make it seem that there's a real, scientific debate going on -- even though there isn't.
But isn't this idea exactly what you don't want?
If so, then why are you vigorously promoting this idea through your actions?
You keep bemoaning the state of the media, the state of politics, the state of public discourse, yet mysteriously you're bent on taking a course of action that (even according to yourself) only serves to further confuse the state of discourse! MT, do you sincerely believe that, by further muddling the state of discourse, the public will, in a bout of 11-dimensional chess, somehow magically see the light and support good science?
Seriously, I simply don't understand why you do what you do.
-- frank
Frank, this is a serious issue, but I don't see how the answer is so obvious.
ReplyDeleteGiven that he attacks me directly on a fairly prominent site, what am I to do, roll over and play dead?
There is also Singh's point,
A researcher could be doing really important work on global warming, and then somebody writes a column in a national newspaper that completely undermines what they’re saying. But the scientist doesn’t think the column is important—it’s just some nincompoop writing a column—so they don’t take that writer to task in the way they should. It’s a case of saying, “How do we make a difference?” We certainly don’t make a difference by just moaning over coffee the next day.
There is no scientific debate.
Fuller genuinely misundertsands this. He himself may be irredeemable, but people who think the way he does are exactly the issue. I don't see what ignoring this way of thinking achieves.
Nor am I taking a position that what he says is legitimate debate. If you read what I said, it was the contrary.
Of course, this is what makes denialists angry, this idea that their opinions in some way "don't count". The problem of course is that they don't count in science but they do count in democracy. So presuming you don;t want to abandon democracy, how exactly do you propose handling it?
With respect to point number 10 this is a concept that was determined thirty years ago, as outlined in a post in RC last year. That is why the Pine Island Glacier was referred to as the weak underbelly of WAIS. That this process has come to pass confirms that the dynamics were understood and correct then.
ReplyDeleteMT:
ReplyDelete"Nor am I taking a position that what he says is legitimate debate."
My bad, I stand corrected. But I still find your response to be too muted and garbled to make it clear that Fuller's talking nonsense.
What do I propose? Go straight to discussing the most easily debunked nonsense first, that's what I'll do -- there's no rule in the world that says that points must be answered in the same order as they appear in Fuller's original article. Start by pointing out, for the benefit of those whose minds aren't in the 'doing sums' mode, that -57Gt ± 52Gt means a range of -109Gt to -5Gt, which is clearly not an increase.
This is very simple to explain and very simple to understand. It doesn't require a whole bunch of introductory material that just flies over people's heads.
Then proceed to take Fuller to task for saying that you, and not himself, referred to the said paper first.
Then talk about the sciencey
stuff.
Maybe someone has better ideas, but for now, the above is what I might have done.
-- frank
This comment has been removed by the author.
ReplyDelete"The mass balance of Antarctica as a whole swamps the events in this area now, so the GRACE instrument may not pick them up. But nobody knows how quickly the destabilization will occur once the ice sheet lets go of its sill in the Amundsen embayment, which as I understand it, it already has. Once it starts, a one-time and abrupt sea level rise of about 2 or 3 meters in a few decades is plausible."
ReplyDeleteMichael were can I read more about this issue?
Here's a nice place to start with a few references to primary literature.
ReplyDeleteGood search keywords are "Pine Island Glacier" "Thwaites Glacier" and "Amundsen Embayment".
A nice overview comparable to the one I just tried to state is here.
glacierchange, if that's the worst criticism from a practicing glaciologist, I am pleased with my effort.
ReplyDeleteStill, Schoof is a nice paper, and I think it moves the phenomenon from the realm of the heuristic to the realm of the mathematically decribed.
I refer to Schoof (2007) Ice sheet grounding line dynamics: Steady states, stability and hysteresis. J. Geophys. Res. Earth Surface, 112, F03S28, doi:10.1029/2006JF000664 .
So, your response to my piece in WUWT is basically, "Huh?" "Huh?" "I'm not a scare artist!" and "Saying that other measurements, consistent with climate theory, show the Antarctic as gaining ice doesn't make it so, even if you say it twice."
ReplyDeleteCan't really respond to Huh. I think you're either a scare artist or a scared artist looking to be contagious.
As for the final point:
Other measurements have shown Antarctica as gaining ice. Here is one example: "rom 1992 to 2003, Curt Davis, MU professor of electrical and computer engineering, and his team of researchers observed 7.1 million kilometers of the ice sheet, using satellites to measure changes in elevation. They discovered that the ice sheet's interior was gaining mass by about 45 billion tons per year, which was enough to slow sea level rise by .12 millimeters per year. The interior of the ice sheet is the only large terrestrial ice body that is likely gaining mass rather than losing it, Davis said.
"Many recent studies have focused on coastal ice sheet losses and their contributions to sea level rise," Davis said. "This study suggests that the interior areas of the ice sheet also can play an important role. In particular, the East Antarctic ice sheet is the largest in the world and contains enough mass to raise sea level by more than 50 meters. Thus, only small changes in its interior can have a significant affect on sea level."
The study, funded by NASA's Cryospheric Processes Program and the National Science Foundation's Antarctic Glaciology Program, suggests that increased precipitation was the likely cause of the gain. This was based on comparisons with precipitation model predictions over the same period of time. The most recent U.N. Intergovernmental Panel on Climate Change reported that Antarctica would gain mass due to increased precipitation in a warming climate. However, the study made no direct link to global warming.
"We need more ice core measurements from East Antarctica to determine if this increased precipitation is a change from the past or part of natural variability," said Joe McConnell of the Desert Research Institute in Reno, Nev., who co-authored the study.
The researchers used satellite radar altimeters from the European Space Agency's ERS-1 and ERS-2 satellites to make 347 million elevation-change measurements between June 1992 to May 2003.
The research team found there was a strong correlation between the predicted precipitation trends and measured elevation change over the 11-year period for the ice sheet, which indicated that East Antarctica's interior was likely gaining mass due to the increased precipitation. The results, though, did not assess the overall contribution of the entire Antarctic ice sheet to sea level rise."
There are others. Here is IPCC TAR:
In the IPCC TAR Chapter 3 Executive Summary is this bullet point:
"Over the period 1979 to 1996, the Antarctic (Cavalieri et al., 1997; Parkinson et al., 1999) shows a weak increase of 1.3 ± 0.2%/decade.
…Satellite data indicate that after a possible initial decrease in the mid-1970s, Antarctic sea-ice extent has stayed almost stable or even increased since 1978."
Here is AR4: "Antarctic sea ice extent continues to show interannual variability and localised changes but no statistically significant average trends, consistent with the lack of warming reflected in atmospheric temperatures averaged across the region. {3.2, 4.4}"
Zwally et al (2002): "The derived 20 year trend in sea ice extent from the monthly deviations is 11.18 ± 4.19 x 103 km2yr-1 or 0.98 ± 0.37% (decade)-1 for the entire Antarctic sea ice cover, which is significantly positive.
...Also, a recent analysis of Antarctic sea ice trends for 1978–1996 by Watkins and Simmonds [2000] found significant increases in both Antarctic sea ice extent and ice area, similar to the results in this paper."
Cont.
NOAA website: "Sea ice in the Antarctic has shown very little trend over the same period, or even a slight increase since 1979. Though extending the Antarctic sea-ice record back in time is more difficult due to the lack of direct observations in this part of the world."
ReplyDeleteAnd this is consistent with climate change theory as developed over time. I assume you're not saying that's made up.
Real Climate (2006): "In the Science paper, Monaghan and others show that there has been no significant change in Antarctic snowfall in the last ~50 years. This is a potentially important result because most calculations suggest that as the globe warms, polar snowfall should increase, somewhat mitigating the sea level rise that is expected to result as the margins of the ice sheets melt and thin."
Real Climate (2008): "Despite the recent announcement that the discharge from some Antarctic glaciers is accelerating, we often hear people remarking that parts of Antarctica are getting colder, and indeed the ice pack in the Southern Ocean around Antarctica has actually been getting bigger. Doesn’t this contradict the calculations that greenhouse gases are warming the globe? Not at all, because a cold Antarctica is just what calculations predict… and have predicted for the past quarter century."
So you can go back to babbling about my scientific illiteracy all you want... But it's just an excuse to hide how weak your arguments are.
Sorry MT, you do not comfort me one bit. I remain alarmed and alarmist. Ice is different from grape jelly near their melting points. Grape jelly does not form moulins through which falling water advect heat into the core of jelly mass. Nor does grape jelly contract as it melts. Ice has a much sharper melting point. Ice has more structural strength than grape jelly, and water has a lower viscosity than melted jelly. In short, grape jelly has different physics.
ReplyDeleteAnd, ice can melt into a structure of small particles of ice loosely bound by some ice bonds and surface tension, but with much lower structural strength than normally associated with ice. Grape jelly does not do this. When Dr. Barber touched such ice in the Arctic ocean, it collapsed into an ice slurry. I think I see similar microwave signatures from some land ice. I think some of our land ice has much less structural strength than the ice guys think it has. I think we will soon see ice structures undergoing progressive collapse under the force of gravity resulting in high speed flows consisting of ice particles with a small volume of melt water.
It is not the standard model, but this is what happened at Lake Missoula. There was a canyon full of ice, and a trickle of water, and the ice collapsed in a flood that bored huge pot holes in hours.
Tom, I try to clarify, and you go back to conflating a bunch of different issues.
ReplyDeleteYour job in writing about this is to DISENTANGLE the issues, and put them into perspective. Instead, you muddle them all together.
In particular, I see at least eight questions you raise in your confused comments. I offer my answer in brief to seven of them, in the hopes that I can remove some of the confusion you reinjected into the discussion.
1) Is the Antarctic interior warming?
This seems to be a close call.
2) Is the Antractic interior in net accretion?
Possibly, but this will eventually be overtaken by decay at the edges. The basic issue is whether this overtaking has already occurred. Most
3) Is the Antarctic interior expected to warm?
I don't know. I wouldn't be surprised to find predictions both ways. The recovery of the ozone hole would lead to surface cooling. The ice surface is at a high altitude, which would also somewhat weaken the greenhouse signal.
4) Is the Antarctic interior expected to grow?
As I understand it, yes, because more moisture will be carried over the plateau.
5) Is the total Antarctic mass flux dominated by the interior?
Measurements say not anymore. Logic says that eventually the fringe decay will win. As I explained above, if you had bothered to read it.
6) Is Antarctic sea ice increasing?
Yes but this is off topic.
7) Is Antarctic sea ice expected to increase?
There are some who argue that it is, and it's a hot topic in blogistan because Curry has a hand in it now. But it really has very very very little to do with the mass balance of the ice sheet, which is the topic your raised.
8) Does this repeated mention of sea ice despite various efforts at correction inidcate any competence at all on these questions? Does Tom Fuller know the basics of the climate of the cryosphere, or is he just ranting aimlessly because he cannot bring himself to believe the implications of climate science?
This question is left as an exercise for the reader.
Re: Tom
ReplyDeleteYour first source uses the word "interior" 5 times, but also specifically says:
"The results, though, did not assess the overall contribution of the entire Antarctic ice sheet to sea level rise."
How is misrepresenting what your chosen source says honest? Cherry picking at the very least.
Your other sources refer to sea ice, lack of anticipated increases in snowfall by some (unspecified) sources and increasing cold over the parts of Antarctica (look up the ozone hole and its effects on the winds encircling the Antarctic continent). If you cannot understand the difference between sea ice and continental glaciation in the form of ice sheets, no one can help you.
In the process of defending your scientific literacy, you confirm your lack of it.
Peddle your sophistry elsewhere among weaker minds than yours. Like at WUWT.
The Yooper
Aaron, the actual details of how the ice spreads at the edges is indeed different from the way jelly would spread at the edges. Moulins and surface hydrology are part of it.
ReplyDeleteMy article was getting long enough, and once you start getting into the details of the surface hydrology you are pushing the limits of what I'm confident saying.
If the table were lumpy and had spots where it was heated from below, conceivably you could get jelly to form moulins like in Greenland. It would take some work to get everything exactly right, though. That's why we use computer models instead when we want to get quantitative. Even so, the phenomenology is complex.
It's odd that you thought this was supposed to be comforting. It was just an attempt to be factual and balanced in contrast to Fuller's wild flailing.
"NOAA website: "Sea ice in the Antarctic has shown very little trend over the same period, or even a slight increase since 1979. Though extending the Antarctic sea-ice record back in time is more difficult due to the lack of direct observations in this part of the world."
ReplyDeleteAnd this is consistent with climate change theory as developed over time. I assume you're not saying that's made up."
What's made up, Tom, is your notion that sea ice and the antarctic ice sheet are the same thing.
Tom's basic problem is that he confuses his ability to quote papers he doesn't understand with knowledge...
ReplyDeleteI think we can all see who's doing the flailing.
ReplyDeleteI note with amusement that my first comment showing numerous citations for other measurements somehow, miraculously, didn't get posted.
I note that you say I attack you on WUWT, without noting how many times you have attacked me here. As you continue to do without justification.
Here are your answers:
1. This seems to be a close call.
2. Possibly.
3. I don't know.
4. As I understand it, yes.
5. Measurements say not anymore. Logic says that eventually the fringe decay will win.
6. Yes but this is off topic.
7. There are some who argue that it is, and it's a hot topic in blogistan because Curry has a hand in it now. But it really has very very very little to do with the mass balance of the ice sheet, which is the topic your raised.
And on the basis of this gigantic intellectual level of certainty you call me scientifically illiterate.
You, on the other hand, Mr. Tobis, who is certain of nothing and terrified of everything, are perfectly capable of insulting, misrepresenting, and repeating your own made-up garbage:
ReplyDelete. Once you say something like "I can't believe Tom Fuller's latest, um, topsy-turvy piece. He really has hid head, um, in the sand, that guy.
Perhaps Fuller doesn't understand that there is no ceiling, no worst case. I would have thought people would not be as foolish as they have been of late.
Tom Fuller is among the people lacking much clue about science, but who is happy to write about it and to try to attract an audience.
Tom Fuller, who has gone about as bonkers as anyone on this innocous publication, shows us just how far around the bend the response to this has been.
Now where the heck does he get that from? OK, kids, be polite. He pulled it out of his, um, hat. Right. Hat.
Tom Fuller, over at Eli's, castigates me for speaking of "bad guys" in the climate change debate. Tom is right on the edge of the category himself...
I think Fuller really thinks he is competent to make judgments on climate science. It's quite absurd; all the other absurdities follow pretty much directly.
And that's not even delving into your kind comment in your own and others' weblogs.
But now I am 'attacking' you. So you refuse to post one of my comments and continue to lie about me.
Pathetic.
As for disentangling the issue, here is what I wrote and to which neither you nor your companions here have attempted to answer:
ReplyDelete"So the paper referred to by scare artists like Michael Tobis of Only In It For The Gold says the Eastern Antarctic has lost 57 billion tons a year–plus or minus 52 billion tons. Hmm. I think we need a few more orbits, myself. Having a margin of error as large as the original figure doesn’t inspire confidence.
But to hear some talk, it’s back to the Day After Tomorrow tidal waves drowning New York. You can always tell when they’re trying to scare you–they talk about firm figures for how much ice is melting, without the data needed to put it into perspective. 57 billion tons certainly sounds like a lot of ice. However, as a percentage of the total it is not even an asterisk. Antarctica has 150 million billion tons of ice…
Do you remember that iceberg that calved off Antarctica in March? (Calving is a perfectly normal event, and has nothing to do with climate change.) The one the size of Rhode Island? It was estimated at 860 billion tons.
“A 2008 study estimated that Antarctica loses about 1.6 trillion metric tons of ice each year, but gets nearly that much back as annual snowfall. The icy continent may suffer a net ice loss of about 100-200 billion metric tons per year, but Scambos said the exact figure remains uncertain.” (Live Science, Is Antarctica Falling Apart? March, 2010).
In my mind these are the key issues to resolve when dealing with analyses of GRACE data.
In essence, what we have here is a new satellite using new tools to take measurements. The data recovered is analyzed using guesses and inferences. Their analysis is presented with a margin of error as large as the amount of ice they say is melting from Antarctica. The loss is is less than 1% of the normal annual melt.
Re: Tom
ReplyDeleteGiven your inability to mount a coherent defense of your position by properly referencing your source paper (to paraphrase what dhogaza said), it is rather surprising that any of your comments get posted at all.
Unless you're using that old "the Internet ate my supporting references" ploy. Oh, wait. You are...
The Yooper
Aha, the damned if you do damned if you don't trap. Informed uncertainty is treated as ignorance.
ReplyDeleteThis is polemics, not argument.
If one can be flamed for not expressing uncertainty, and flamed for expressing uncertainty, flamed for saying "it's near zero" in the one case and flamed for saying "it's obviously negative" in the other, you can't say anything.
This way of approaching reality is destructive and counterproductive in the extreme.
The topic at hand, the topic that Fuller raised the first time, is points 4 and 5, where the balance of evidence is clearly on one side and Fuller is clearly on the other.
The other issues, which are harder, are the smokescreen Fuller puts up to distract from the part where his main point is wrong. The fact that they are harder doesn't mitigate Fuller's incorrectness on the main points at hand.
It seems Fuller has quickly moved from being inadvertently wrong to being defensively wrong and willfully ignorant, a choice which I would call unethical.
Fuller's comment got caught in the spam filter. Google apparently got it wrong.
ReplyDeleteOr... ?
Or...?
ReplyDeleteAnd you are the one trying to distract and confuse the issue.
I do not for one second believe that expressing uncertainty is wrong. I do believe that it is a flimsy reed on which to base untrue allegations, even if they are the same baseless allegations you have been pushing for a year.
Shall I recollect the citations and submit them again as a comment? Is there any point? Do you really believe that there are no credible measurements of Antarctic ice growing prior to GRACE reports? Really?
And what if my next comment gets disappeared?
I note with amusement that my first comment showing numerous citations for other measurements somehow, miraculously, didn't get posted.
ReplyDeleteWhen you think the SPAM filters are all out to get you, it's time to see a pshrink.
Well, if I do them one at a time perhaps I won't be as annoyed if you disappear inconvenient ones.
ReplyDelete"From 1992 to 2003, Curt Davis, MU professor of electrical and computer engineering, and his team of researchers observed 7.1 million kilometers of the ice sheet, using satellites to measure changes in elevation. They discovered that the ice sheet's interior was gaining mass by about 45 billion tons per year, which was enough to slow sea level rise by .12 millimeters per year. The interior of the ice sheet is the only large terrestrial ice body that is likely gaining mass rather than losing it, Davis said."
The study, funded by NASA's Cryospheric Processes Program and the National Science Foundation's Antarctic Glaciology Program, suggests that increased precipitation was the likely cause of the gain."
In the IPCC AR4 the situation is described like this in Chapter 4, “Observations: Changes in Snow, Ice, and Frozen Ground” (p. 351):
ReplyDeleteAs an example, an updated version of the analysis done by Comiso (2003), spanning the period from November 1978 through December 2005, is shown in Figure 4.8. The annual mean ice extent anomalies are shown. There is a significant decreasing trend in arctic sea ice extent of –33 ± 7.4 × 103 km2 yr–1 (equivalent to –2.7 ± 0.6% per decade), whereas the Antarctic results show a small positive trend of 5.6 ± 9.2 × 103 km2 yr–1 (0.47 ± 0.8% per decade), which is not statistically significant. The uncertainties represent the 90% confidence interval around the trend estimate and the percentages are based on the 1978 to 2005 mean.
Re: Tom
ReplyDelete"Well, if I do them one at a time perhaps I won't be as annoyed if you disappear inconvenient ones."
Resorting to ad hominems now? Weak.
With every comment you make here, you further reinforce Michael's last assessment:
"It seems Fuller has quickly moved from being inadvertently wrong to being defensively wrong and willfully ignorant, a choice which I would call unethical."
I personally consider MT to be unfailingly impartial to either side of the AGW (politicized) debate; he time and again takes the side of the science and the facts. Neither of which support your side, Tom.
The Yooper
The Yooper
From the NY Times: "The eastern half of Antarctica is gaining weight, more than 45 billion tons a year, according to a new scientific study.
ReplyDeleteData from satellites bouncing radar signals off the ground show that the surface of eastern Antarctica appears to be slowly growing higher, by about 1.8 centimeters a year, as snow and ice pile up.
The gain in eastern Antarctica snow partly offsets the rise in sea level caused by the melting of ice and snow in other parts of the world. The finding also matches expectations that the earth's warming temperatures would increase the amount of moisture in the air and lead to greater snowfall over Antarctica.
''It's been long predicted by climate models,'' said Dr. Curt H. Davis, a professor of electrical and computer engineering at the University of Missouri and the lead author of a paper that was published on the Web site of the journal Science yesterday. ''This is the first observational evidence.''
The accumulation occurring across 2.75 million square miles of eastern Antarctica corresponds to a gain of 45 billion tons of water a year or, equivalently, the removal of the top 0.12 millimeter of the world's oceans."
Funny how it seems to be easier for you to talk about me, my education and my temperament than it is to discuss the results I am presenting to you.
ReplyDeleteFunny, but not unusual.
There are many measurements of Antarctic land mass ice extent that indicate it is increasing.
It is congruent with accepted climate change theory about what is supposed to happen as the world warms.
I do not for one second believe that expressing uncertainty is wrong. I do believe that it is a flimsy reed on which to base untrue allegations
ReplyDeleteEither it's uncertain or it's untrue, Tom. You can't say you're uncertain about a proposition and at the same time make a definitive statement about the truth value of that proposition.
You seem to be saying that you disagree with the finding that "the mass flux is clearly negative from all major ice sources." A persuasive case would include some specific refutation of that finding.
ALARM
ReplyDelete1: disturb, excite
from
Merriam-Webster
ALARMISM
: the often unwarranted exciting of fears or warning of danger
from
Different page
Do try to use the words with some care, please.
Re: Tom
ReplyDeleteYour references (IPCC/Comiso 2003 and Davis 2005) both refer specifically to the Antarctic interior gaining mass.
Velicogna 2006 clearly shows that both the WAIS and EAIS (interior and coasts combined), separately and together, are losing mass.
Again, you fail to consider all of the data available.
This is becoming fun, however.
The Yooper
Discovery Indicates that Ice Sheet once Thawed
ReplyDeletein agreement with the underlying rock being below sea level between the Admunsen Sea and the Weddell Sea.
This will happen again; the only question is the rate and ultimate extent of SLR.
PDA, perhaps I should use shorter words.
ReplyDeleteIt is our host who expresses uncertainty and then attacks me. I know that the words used in his attacks are not true.
Hence my irritation.
57 billion tons a year–plus or minus 52 billion… a margin of error as large as the original figure
ReplyDeleteUm, no: 57 > 52, and as Frank pointed out, "-57Gt ± 52Gt means a range of -109Gt to -5Gt, which is clearly not an increase."
“The icy continent may suffer a net ice loss of about 100-200 billion metric tons per year... The loss is is less than 1%
Notice anything interesting about these statements, chief? (For those of you playing at home: loss:increase::day:night.)
Satellite data indicate that after a possible initial decrease in the mid-1970s, Antarctic sea-ice extent has stayed almost stable or even increased… Antarctic sea ice extent continues to show interannual variability… The derived 20 year trend in sea ice extent... a recent analysis of Antarctic sea ice trends… the ice pack in the Southern Ocean around Antarctica has actually been getting bigger… The annual mean ice extent anomalies are shown."
As others have asked, do you know the difference between ice mass flux and ice extent?
"the ice sheet's interior was gaining mass by about 45 billion tons per year"
So finally, we get to a reference that mentions "mass," However, even this reference makes it clear that looking only the Antarctic interior gives an incomplete picture of mass flux: "The overall contribution of the Antarctic ice sheet to global sea-level change will depend on how mass changes in the ice sheet's interior balance mass changes from the coastal areas."
Sorry, Mr. Fuller: I award you no points, and may God have mercy on your soul.
Mr. PDA, I cannot be monosyllabic all the time.
ReplyDeleteMy point is not the polarity of the signal measured. I am well aware that their data comes back with negative mass.
My points are:
That the margin of error is as large as the result.
That the total observed ice loss is less than 0.5% of the annual melt loss.
Hence we should treat this data with caution.
What on earth is even mildly controversial about this?
Since WTFUWT doesn't deserve a link, why give it one? If people really feel the need to wallow in the muck, that's what Teh Google is for.
ReplyDeleteWord Verification: disess
No criticism MT, you did well, just a historical update, that shows glaciology saw this coming 30 years ago. The mass flux issue is dominated in Greenland and in WAIS by the ice discharge rates which vary considerably depending on the glacier. Pine Island Glacier is the WAIS equivalent of the Jakobshavn for the GIS. In both cases these are dominated by the dynamics at the ice front not surface melting. Much of the sensitivity is the depth of the glacier bed. Further north some glaciers do not have the same capabilities to discharge ice from the interior of the GIS, note Humboldt Glacier. Each glacier has its own story.
ReplyDeleteJust to refresh our memories, didn't this all start rather more simply?
ReplyDeleteTom had said on WUWT: "Sea levels are not going to rise by 20 feet. Or 10. Or five."
In defending this statement here, Tom averred: "I absolutely do not believe those saying that sea level rise will be more than the 18-59 cm projected in AR4." And then, when it was pointed out that this did not include ice sheet melt, he proclaimed that: "FWIW, I think accumulation in SH will more than balance out loss in NH and as I wrote, I think Greenland will lose a little around the edges."
When it was pointed out that both Greenland AND Antarctica are in signficant net mass loss, he seems to be trying to counter with two main lines of argument.
1. Parts of the Antarctic ice sheets may/are gaining mass - but he never ever seems to acknowledge/grasp that his premise that the entire southern hemisphere can offset the northern hemisphere if bogus if Antarctica is in NET loss. And the regular return to discussions about sea ice is “bogus squared”, totally non sequitur*.
and
2. A dismissal of the GRACE results as some combination of (a) contrary to what other (unknown) results that indicate net gain in Antarctica; (b) too preliminary and error prone; and (c) a refutation of climate predictions.
The first point is just a futile point to get bogged down on. Tom no longer seems to even be trying to defend his point about offsetting hemisphere changes, but neither does he acknowledge that it is wrong, wrong, wrong. Instead, we are arguing about whether East Antarctica is specifically losing mass. It certainly appears that it is, but it is also a total distraction from the point that his overall premise is egregiously wrong. Does he still stand by the claim that SLR will be less than 59 cm? (Even with or without caveats on "this century"?)
The second point seems just a desperate attempt to avoid dealing with results that don’t conform to his premise that this whole climate change thing is no big deal. And if there is “big deal” evidence, he’s somewhat like a lawyer manoeuvring to having certain evidence ruled “inadmissible”. But there is little offered in support of any this, except for personal conjuecture and a seeming presumptive dismissal that GRACE isn't yet telling us anything of use. But he still doesn't get around to addressing the fact that multiple lines of evidence are confiming ice mass loss from Antarctica.
Anyway, it’s kind of hard to follow all this, because we are jumping all over the place, so I just thought I would summarize, as best as I can recall it all. Seems to me the onus is on Tom to support his contentions that (a) net GLOBAL ice sheet mass loss is/will be largely inconsequential in terms of SLR, because (b) the Southern Hemisphere is gaining sufficient mass to offset the NH losses.
As far as I can tell, he’s not even close to doing so. I would say he is about 57 miles away from close, +/- 52 miles.
* Ha ha. In making sure my spelling of “non sequitur” was correct, Wikipedia gives a demonstration:
Q: How many surrealist painters does it take to change a light bulb?
A: Fish.
Heh. Maybe we can edit the entry and have it link to this thread!
One nit: ice911 can't solve the general ice-sheet problem, although it might help indirectly. The idea is to make cheap floating rafts of high-albedo material around the edges of the Arctic ice. of course that's likely the highest payoff place in the world to do that, given:
ReplyDeletea) High albedo difference from ocean to white material.
b) Right where ice-albedo feedback works.
Unfortunately, covering Greenland with aluminum foil is not so useful (I once back-of-enveloped ~ 3 years of world aluminum production :-))
I don't know what Leslie's current design look like, the older ones were like like cloth-covered hula hoops. I suppose these might work in Northern lakes as well, and I'd guess they might be useful for covering reservoirs and canals in hot dry climates (like California), which would also cut evaporation, not a bad thing.
I am well aware that their data comes back with negative mass.
ReplyDeletebut
Other measurements, consistent with climate theory, have consistently shown the Antarctic gaining, not losing ice.
The problem isn't that you use too many syllables, sport. You are saying two contradictory things. If you want to do that in words of less than five words each, it's still saying two contradictory things.
the margin of error is as large as the result.
Well, it's not as I said before, but it's your cite, as MT has said before. It's also the Eastern Antarctic, not the continent as a whole, as everyone has said before.
If you looked at Velicogna et al. 2006 as Daniel Bailey had suggested, you'd see an finding of -152 ± 80 km3/year of ice. If the corrections noted by Wu et al. hold, we're still talking 64±32 billion tonnes. Not increasing. Not within the margin of error.
It's not "treating data with caution" to cherry-pick and misrepresent it.
Why not respond substantively instead of these "monosyllabic" grade-school taunts?
John, if we build an ice sheet in the Amundsen Bay it seems to me we might plug the leak in the WAIS, no?
ReplyDeleteRust Never Sleeps,
ReplyDeleteYour attempt to summarize this discussion is needed badly, but sadly does not serve due to your own preconceptions.
I do believe that SLR this century will fall between 18 and 59 cm, as predicted by the IPCC absent significant contributions from ice caps.
I do not believe there will be signficant contributions from ice caps this century.
A decade of observation in the Antarctic consistently found net ice increases. I am not convinced by GRACE results, in part because it conflicts with what climate change theory predicts about ice mass in the Antarctic, and in part because of ambiguities in the data and analyses noted above.
I have given citations on each of my points.
I like my summary better.
In an attempt to provide more summarization, Tobis says in his post:
ReplyDelete"Other measurements, consistent with climate theory, have consistently shown the Antarctic gaining, not losing ice.
No. That is wrong. Say it twice and it's still wrong.
Fuller seems to believe in making up facts to tell a convenient story. I don't think this constitutes helping."
Fuller provides: "From 1992 to 2003, Curt Davis, MU professor of electrical and computer engineering, and his team of researchers observed 7.1 million kilometers of the ice sheet, using satellites to measure changes in elevation. They discovered that the ice sheet's interior was gaining mass by about 45 billion tons per year, which was enough to slow sea level rise by .12 millimeters per year. The interior of the ice sheet is the only large terrestrial ice body that is likely gaining mass rather than losing it, Davis said."
The pack responds that the interior is only part of Antarctica.
They don't bother to note the relative sizes.
Tobis responds: "4) Is the Antarctic interior expected to grow?
As I understand it, yes, because more moisture will be carried over the plateau.
5) Is the total Antarctic mass flux dominated by the interior?
Measurements say not anymore. Logic says that eventually the fringe decay will win."
And then, yap, yap, yoop yoop.
We can't find evidence of intelligent conversation here. And it's a travesty that we can't.
Here's NASA with a final thought:
Two-thirds of Antarctica is a high, cold desert. Known as East Antarctica, this section has an average altitude of about 2 kilometer (1.2 miles), higher than the American Colorado Plateau. There is a continent about the size of Australia underneath all this ice; the ice sheet sitting on top averages at a little over 2 kilometer (1.2 miles) thick. If all of this ice melted, it would raise global sea level by about 60 meter (197 feet). But little, if any, surface warming is occurring over East Antarctica. Radar and laser-based satellite data show a little mass loss at the edges of East Antarctica, which is being partly offset by accumulation of snow in the interior, although a very recent result from the NASA/German Aerospace Center's Gravity Recovery and Climate Experiment (Grace) suggests that since 2006 there has been more ice loss from East Antarctica than previously thought 5. Overall, not much is going on in East Antarctica -- yet.
So on the one hand we have the people who study ice for a living and who are very concerned and then we have a journalist on the other hand that doesn't believe they need to be so nervous.
ReplyDeleteHmm...so many tough choices.
Too close to call. I will look at previous examples to see what happened.
When Antarctica was last ice-free, sea levels were 70m (~230 feet) higher than today and CO2 levels were around 425 ppm. Given that we are on track for 3C or higher by 2100, I will side with the experts and be very concerned that seas will inundate us eventually, even if it isn't in this century.
What happens if we pass a tipping point and the melt cannot be stopped even when the world finally wises up? As Clint Eastwood would say, Do you feel lucky, punk?"
Tom, you'd be well advised to stop digging.
ReplyDeleteThe NYTimes peice (from 2005) is here. Points from that piece that Tom somehow forgot to mention:
"The gain in eastern Antarctica snow partly offsets the rise in sea level caused by the melting of ice and snow in other parts of the world. The finding also matches expectations that the earth's warming temperatures would increase the amount of moisture in the air and lead to greater snowfall over Antarctica."
"Dr. Thomas said that there could be as-yet-unseen melting of ice along the edges of Antarctica, where the satellites could not map the steeper coastal topography. "
OK? Consistent with what I've been saying? Yep. Or for the Yoopers in the audience, yoop.
As for this: " decade of observation in the Antarctic consistently found net ice increases"
No. No, no, no, no, no.
This is the whole point, Tom. This is completely, utterly wrong. The more you say it, the less it looks like a mistake and the more it looks like bullshit.
Every single piece of evidence you've brought to refute the GRACE estimate talks about either 1) the east Antarctic interior, not the entire continental mass balance or 2) sea ice. Neither is germane to the number you are debating. The figure in the posting shows the recent results for the continental balance.
As I understand it, recent evidence supports Thomas' 2005 conjecture above that the East Antarctic fringe is in retreat.
From a 2008 JPL press release: Rignot said scientists are now observing these climate-driven changes over a significant fraction of the West Antarctic Ice Sheet, and the extent of the glacier ice losses is expected to keep rising in the years to come. "Even in East Antarctica, where we find ice mass to be in near balance, ice loss is detected in its potentially unstable marine sectors, warranting closer study," he said.
(see the map at that link)
Now as for this:
"That the total observed ice loss is less than 0.5% of the annual melt loss."
a) what does that even mean? (It's too unclear for me to even express an opinion, never mind investigate.)
b) if it means anything, what is the evidence for it?
If you already provided a reference for this, please be good enough to remind me. I really have no idea what this item is about.
As for -57 +/- 52 being indistinguishable from zero, the mind just boggles. Please be so kind to write this as -1057 +/- 52 + 1000.000 so as to increase its accuracy.
As a lawyer, I've been trained to separate truth from b*llsh*t, and Tom has really set off my bs meter.
ReplyDeleteOn the science, even a non-expert like me can tell the difference between a part (East Antarctica), the whole, and the unrelated (sea ice).
I also note that Mr. Fuller fails to address what will happen to sea rise more than 100 years out. It may be the case that our descendants will have the wealth and technology to address sea level rise. It may also be the case that the destruction of ports, marshes, and groundwater basins providing potable water will be far more expensive to address than expected. It's also worth noting that in every other environmental contamination problem, avoidance has turned out to be orders of magnitude less expensive than cleanup.
As to tone, Mr. Fuller doesn't exactly cover himself with dignity when he refers to MT as a "either a scare artist or a scared artist looking to be contagious", or puts him in the class of "apocaholics". In my extensive experience, that type of communication tends to stifle dialog rather than promote it (to say the least).
"Every single piece of evidence you've brought to refute the GRACE estimate talks about either 1) the east Antarctic interior..."
ReplyDeleteHmmm, which bits of the antarctic ice sheet are likely to land in the ocean, melt, and cause sea level to rise?
Those bits along the fringe, or those bits deep in the interior far, far away from the sea?
Enquiring minds wonder, Tom.
"They discovered that the ice sheet's interior was gaining mass by about 45 billion tons per year, which was enough to slow sea level rise by .12 millimeters per year."
ReplyDeleteTom fails to note that they're not claiming that the mass transported to the interior is great enough to reverse sea level rise, simply to slow it.
Regardless, Tom, accumulation in the interior is a totally separate mechanism than loss along the fringe.
The fact that whether or not the sum of the rate of change of these two mechanisms is positive or negative doesn't overthrow or support the equally separate scientific arguments which describe them.
Two phenomena, two scientific arguments, Tom insists that there's only one Theory of Climate Change.
That's a pretty basic misunderstanding.
“As climate shifts, Antarctic ice sheet is growing” –Los Angeles Times, May 20, 2005
ReplyDelete“Scientists link global warming to Antarctic’s ice cap’s growth” –Chicago Tribune, May 20, 2005
“Antarctica ice cap thickens” –Pittsburgh Post Gazette, May 20, 2005
“Warming is blamed for Antarctic’s weight gain” –New York Times, May 20, 2005
“Ice sheet confounds climate theory” – The Telegraph, May 20, 2005
“Antarctica ice cap thickens, slowing rise in sea levels” – Pioneer Press, May 20, 2005
As for Curtis et al, The study region covered about 70% of the total ice sheet area–the satellites couldn’t “see” all the way to the South Pole due to orbital constraints, and the altimetry doesn’t work well in areas of rough terrain such as along the coastline.
"We find that data from climate model reanalyses are not able to characterise the contemporary snowfall fluctuation with useful accuracy and our best estimate of the overall mass trend—growth of 27+/-29 Gt yr^-1 —is based on an assessment of the expected snowfall variability. Mass gains from accumulating snow, particularly on the Antarctic Peninsula and within East Antarctica, exceed the ice dynamic mass loss from West Antarctica." D. J. WINGHAM, et al, "Mass balance of the Antarctic ice sheet," Phil. Trans. R. Soc. A (2006) 364, 1627–1635, p. 1627
"We show that 72% of the Antarctic ice sheet is gaining 27+/-29 Gt yr^-1, a sink of ocean mass sufficient to lower global sea levels by 0.08 mm yr^-1." D. J. WINGHAM, et al, "Mass balance of the Antarctic ice sheet," Phil. Trans. R. Soc. A (2006) 364, 1627–1635, p. 1634
"We have used ice-flow velocity measurements from synthetic aperture radar to reassess the mass balance of the Ross Ice Streams, West Antarctica. We find strong evidence for ice-sheet growth (26.8 gigatons per year), in contrast to earlier estimates indicating a mass deficit (20.9 gigatons per year). Average thickening is equal to ~25% of the accumulation rate, with most of this growth occurring on Ice Stream C. Whillans Ice Stream, which was thought to have a significantly negative mass balance, is close to balance, reflecting its continuing slowdown. The overall positive mass balance may signal an end to the Holocene retreat of these ice streams." Ian Joughin and Slawek Tulaczyk, "Positive Mass Balance of the Ross Ice Streams, West Antarctica" Science, 295(2002), p. 476
Going way, way back in the thread, Frank and Scott mused about whether or not "engaging" on these sorts of frustrating disabusings of disinformation is productive...
ReplyDeleteWith that question, this subsequent thread, and the image of banging one's head against a wall in mind, I am reminded of the Woody Allen quote:
"More than any time in history mankind faces a crossroads. One path leads to despair and utter hopelessness.... the other to total extinction." ;)
So what does Fuller do when refuted? Ignore the refutation and post various unsourced copy and pastes conflating various issues and confusing sea ice and ice sheets. MT exhibits enormous patience sorting it out for him, knowing full well Fuller will just repeat the same stuff on the same thread or later.
ReplyDeleteFuller hosts a blog where he gets paid for web traffic, and web traffic is gained by providing red meat for the ideologues. Debunk him here, but don't feed the troll.
The pack responds that the interior is only part of Antarctica. They don't bother to note the relative sizes.
ReplyDelete"The pack" of a half-dozen people engaging you on this issue, Tom, respond that measurements show NET ice loss throughout Antarctica. Full stop.
We did not mention the size of East (or Greater) Antarctica for the same reason we did not mention the mating habits of the emperor penguin or the height of the Gamburtsev mountains or the growth rate of Buellia frigida in the McMurdo Dry Valleys: because these data are totally, completely irrelevant to the question at hand.
It turns out that Fuller is following in the footsteps of CEI, which several years back based an ad campaign in part on the same misrepresentation of the results of the altimeter studies:
ReplyDelete'Prior to Davis' 2005 study, the U.N. Intergovernmental Panel on Climate Change said that if global warming were occurring, increased precipitation in Antarctica's interior would likely result. In his study, Davis reported growth in the interior East Antarctica ice mass. He said this growth was probably caused by an increase in precipitation, and made it clear in his study that growth of the interior ice sheet is “a predicted consequence of global warming.” Davis said his study did not include the coastal areas of Antarctica, which are known to be losing mass at a rate that could easily offset or outweigh increases in the interior areas.
'"On one of those ads, they [CEI] chose to use the result I published last year to basically say the ice sheets are growing and not shrinking," Davis said in an interview with the Columbia Daily Tribune. "It’s a blatant misuse of our result to create confusion where confusion does not exist."'
"Poe" or no?:
ReplyDelete"I put it to you, Thomas Fuller, that your series of posts themselves are part of a ‘coordinated media strategy using calenders’. An evolved stategy, carefully planned, with the intention of increasing the reputation of the scientists and their carbon theories before implementing taxations."
And naturally, of course, when they cannot comment on the citations provided, it's back to the character assassination, ad homs, lies and insults.
ReplyDeletePerfectly predictable. Perfectly nauseating.
Faded Bloom, I neither follow nor pay attention to CEI, unlike you, who chooses to mimic some of their baser tactics. Funny how you drag CEI into this conversation and ignore the Phil Trans R. Soc... guess they're just another denialist rag.
PDA, I provide you with citations from peer reviewed academic studies that say that Arctic ice mass is rising. You wave your hands.
Rust Never Sleeps, in honor of your inability to address anything like the topic at hand, I command you to wear your underwear on the outside of your clothing. From back when Woody Allen was funny.
New York, yes, I'm sure citing academic peer-reviewed studies that say Antarctic ice mass is increasing is off topic for you. When the topic is sliming someone, you can't let facts get in the way.
See that "WH" in the figure?
ReplyDeleteThat's the Wingham result Fuller cites. (See Alley, Spencer and Anandakrishnan Ann. Glac. 46)
OK, there is one result that shows growing ice, which although it actually OVERLAPS the zero line, we need to take seriously because it SUPPORTS Fuller, as opposed to the GRACE data which don't overlap the zero line but get close to it, which we are to ignore, because Fuller doesn't like it.
Stipulate, then, that there is a study, somewhat on the early side, showing net growth of Antarctica. I would already have stipulated it, but Fuller has done us the kindness of identifying the study in question.
However, the claim wasn't that there was one such study. The claim was that there were a lot of them, all of them, etc.
The only other evidence provided so far (aside from what I already showed in the figure) is some newspaper headlines form the same week all presumably tracing back to a single press release about the Davis study which we've already determined doesn't address the continental mass flux.
It's all still craziness. Do you really expect the ice mass to increase forever while the globe warms indefinitely? What is the point here?
Oh, right, the point is that Michael Tobis is a bad person who will go out of his way to scare people by selective use of evidence. And that Tom Fuller is the epitome of balance and fairness.
I remain unconvinced, but I suppose I might be biased on the question.
No Michael, and no matter how you try to redefine the point, the points are:
ReplyDelete1. Climate change theory predicts ice accumulation in Antarctica for the first part of this century.
2. Observations (yes, plural) from other sources support that theory.
3. GRACE does not. However, there are problems with initial assumptions, margin of error, and risk of signal being lost in the noise of annual ice melt that mean the subject warrants much further study before making hysterical pronouncements.
Those are the relevant points.
This comment has been removed by the author.
ReplyDelete1. Climate change theory predicts ice accumulation in Antarctica for the first part of this century.
ReplyDeleteReally? Citation please, ideally from a consensus document or at least a literature review in a refereed journal.
In fact, do you even have a single refereed source for this "prediction"?
2. Observations (yes, plural) from other sources support that theory.
Well, we have the one, which I came to the table with in the first place.
3. GRACE does not. However, there are problems with initial assumptions, margin of error, and risk of signal being lost in the noise of annual ice melt that mean the subject warrants much further study before making hysterical pronouncements.
This is really the issue. What "hysterical pronouncements" were made by me? Or by anybody else?
Oh, by the way, what is the "noise of annual ice melt" in Antarctica? I would have thought liquid runoff from Antarctica was negligible, but feel free to correct me if I am wrong.
So anyway, you are 0 for 3. I believe that is known as striking out.
Observations (yes, plural)
ReplyDeleteplu·ral [ploor-uhl] -adjective: consisting of, containing, or pertaining to more than one.
??
Ironically, in the abstract to the 2006 Wingham et al, they state:
ReplyDelete"our best estimate of the overall mass trend: growth
of 27 +/- 29 Gt/yr
So, you see, in this case, a relatively tiny net flux number (compared to the vastness of the Antarctic ice sheet mass!) is something we need to pay close attention to. And even though it has an error bar that is actually larger than the mass flux it estimates? Yes, we need to pay close attention to this study. Definitely.
Alrighty then.
But a subsequent result of "-57 +/- 52 GT/yr"? That will require "a few more orbits" before we can possibly consider it. It's quite likely wrong, after all.
profmandia --- WAIS melting already is unstoppable, along with GIS. The only questions are rate and extent.
ReplyDeleteOff-topic, but intended to elict furthr commentary from MT on the inanity of (some) economists:
ReplyDeleteImportant Results from Micro(economics), a pdf file
> Observations (yes, plural)
ReplyDeleteBluster equals clickseeking.
Citing old information while ignoring new? Boring.
Try citations, e.g. here:
http://www.ingentaconnect.com/content/igsoc/agl/2007/00000046/00000001/art00002
http://www.igsoc.org/annals/46/a46a053.pdf
Ice-sheet mass balance: assessment, attribution and prognosis
Annals of Glaciology 46 2007
Richard B. ALLEY, Matthew K. SPENCER, Sridhar ANANDAKRISHNAN
"ABSTRACT. Contrary to prior expectations that warming would cause mass addition averaged over the Greenland and Antarctic ice sheets and over the next century, the ice sheets appear to be losing mass, at least partly in response to recent warming. With warming projected for the future, additional mass loss appears more likely than not."
"... ICE-SHEET MASS BALANCE
In assessing the state of our field, Houghton and others (2001) highlighted the large uncertainties, but found a central estimate that the net ice-sheet response to warming would be slight growth averaged over the next century. Snowfall increase on Antarctica and central Greenland was projected to exceed increase in low-altitude melting ...."
...
"... PROGNOSIS
The projections of warming adding mass to the ice sheets averaged over the next century were based on state-of-the-art ice-sheet flow models forced in various ways. As reviewed briefly by Alley and others (2005), those models did not accurately project the coastal changes that have since occurred around parts of the ice sheets...."
_________
1. Climate change theory predicts ice accumulation in Antarctica for the first part of this century.
ReplyDeleteWhen does the first part of this century end? From the figure in the post it looks like it might have been 2005.
Since Tom is still ignoring my points, I guess that makes me 4-0 by default vs the newsguy-turned-wiseguy-formerly-known-as-Tom.
ReplyDeleteThe Yooper
> noise
ReplyDeleteIf meant to imply audible water on the surface, citation needed
> liquid runoff
Described; not quantified
http://scholar.google.com/scholar?q=subglacial+water+discharge+antarctica
http://www.igsoc.org/journal/34/116/igs_journal_vol34_issue116_pg95-101.pdf
http://www.nature.com/ngeo/journal/v1/n12/full/ngeo356.html
http://www.nature.com/ngeo/journal/v3/n7/full/ngeo890.html
This graphic might help put Fuller's various meanderings, obfuscation, and insults into context:
ReplyDeleteMass balance estimates of Antarctica
Detailed discussion
So Fuller finds a single study from a less-than-recent time period that loosely support his hypothesis, and routinely dismisses all the others. And...
"...uses a low resolution radar altimeter which has a bias towards showing mass gains as discussed previously (Part Two). Some people may challenge this assertion but Thomas et al (2008) set out to find whether Radar Altimetry does create a bias towards more positive values. Their results? Radar Altimetry caused ice losses in Greenland to be less than measured by Icesat (extremely accurate) by 75 GTyear because of this bias."
Note that the individual touting the Wingham et al. study is another WUWT contributor, so we know where Fuller probably gets his stuff from.
Lastly, Shepherd and Wingham 2008:
"show that two of the main glaciers in two of those basins (Totten and Cook glaciers) are losing mass and that these losses were accelerating by 2003.
Here's their study:
Antarctic glacier thinning, 1992-2003, Andrew Shepherd; Duncan J. Wingham
Note the conclusion:
"These glaciers are sited in both East and West Antarctica and, because they are susceptible to changes in climate, we anticipate they will provide a substantial contribution to global sea levels over the twenty-first century should ocean warming continue as projected (Gille, 2002). "
Time for Fuller to throw Wingham into the "alarmist" camp?
Kudos to John Cook. His hours of research and readable summaries saves us a lot of time.
I see MT has already posted that graphic. Oh well. Fuller could use a refresher. His posts indicate that he hasn't read much of anything here.
ReplyDeleteOh, he reads them all right, but only so far as he needs to in order to come up with a non sequitur dodge that he imagines will trick his idiot followers into thinking there's something to his ideas, and then when he's challenged it's on to the next one. It's a classic Gish Gallop. What's interesting about it is that he seems to have decided that the pretense of respectability he appeared to once value is no longer worth having. That was worth finding out, I suppose.
ReplyDeleteBTW, Michael, in the first paragraph of your exposition it should read "substantial fringe of *East* Antarctica" rather than West.
Steve, correct, thanks, and fixed.
ReplyDeleteSee? This is how my breaks disappear. Instead of getting up, stretching my legs and breathing fresh air, I look at the inanity and insanity that is Only In It For the Gold.
ReplyDeleteNew York, you seem to be selectively quoting.
Mass balance of the Antarctic ice sheet
B Y D. J. W INGHAM 1, * , A. S HEPHERD 2 , A. M UIR 1
Centre for Polar Observation and Modelling, University College London,
Gower Street, London WC1E 6BT, UK
2
Centre for Polar Observation and Modelling, Scott Polar Research Institute,
University of Cambridge, Lensfield Road, Cambridge CB2 1ER, UK
3
British Antarctic Survey, High Cross, Madingley Road, Cambridge
CB3 0ET, UK
"4. Conclusions
We show that 72% of the Antarctic ice sheet is gaining 27G29 Gt yrK1, a sink of
ocean mass sufficient to lower global sea levels by 0.08 mm yrK1."
The Antarctic contribution to sea-level rise has long been uncertain. While regional
variability in ice dynamics has been revealed, a picture of mass changes throughout the
continental ice sheet is lacking. Here, we use satellite radar altimetry to measure the
elevation change of 72% of the grounded ice sheet during the period 1992–2003.
Depending on the density of the snow giving rise to the observed elevation fluctuations,
the ice sheet mass trend falls in the range K5–C85 Gt yrK1. We find that data from
climate model reanalyses are not able to characterise the contemporary snowfall
fluctuation with useful accuracy and our best estimate of the overall mass trend—growth
of 27G29 Gt yrK1—is based on an assessment of the expected snowfall variability. Mass
gains from accumulating snow, particularly on the Antarctic Peninsula and within East
Antarctica, exceed the ice dynamic mass loss from West Antarctica. The result
exacerbates the difficulty of explaining twentieth century sea-level rise.
TAR
ReplyDeleteFor Antarctica (Table 11.6), the ice discharge dominates the uncertainty in the mass balance of the grounded ice sheet, because of the difficulty of determining the position and thickness of ice at the grounding line and the need for assumptions about the vertical distribution of velocity. The figure of Budd and Smith (1985) of 1,620x1012 kg/yr is the only available estimate. Comparing this with an average value of recent accumulation estimates for the grounded ice sheet would suggest a positive mass balance of around +10% of the total input, equivalent to -0.5 mm/yr of sea level.
Yeah, right.
ReplyDeleteF refers to just one article out of the fourteen in this issue.
http://rsta.royalsocietypublishing.org/content/364/1844.toc
Reading articles in the rest of the issue puts that one F likes in perspective. Checking subsequent references does too.
http://rsta.royalsocietypublishing.org/cgi/crossref-forward-links/364/1844/1627 includes, for example, this mention:
"... the most profound changes in the ice sheets currently result from glacier dynamics at ocean margins." http://www.nature.com/nature/journal/v461/n7266/full/nature08471.html
Grabbing just one notion, that uses one set of instruments to look at one area, then claiming more than the authors do, is rhetoric. Effective? Only if you like that sort of thing.
There are obviously a bunch of bright guys posting here, but IMHO, some of you are missing, or glossing over valid concerns about the way GRACE satellite data is processed. Keep in mind this is gravity data from a new satellite. Gravity measurements indicate a loss of mass, which is most likely, (but not necessarily) from a loss of ice.
ReplyDeleteSeveral posters at WUWT correctly point out potential pitfalls with the way the raw data is processed. These are valid scientific concerns that need to be resolved and put to rest before the processed data can be trusted:
1) A fairly simplistic, un-calibrated computer model is used to adjust the satellite data for mantle rebound from the last glaciation ~12,000 years ago.
2) After processing GRACE data from the western Antarctic, the calculated loss of ice was so large that an expedition was sent to verify the numbers. They found that the processed data overestimated ice loss by a substantial amount.
3) GRACE should open their systems and software so that people can see exactly how they are processing the raw data from the instruments.
4) Statistically “manipulated” or “interpolated” data is not “observational data”, and should never be referred to as such.
Clearly, there are errors in the way the data is processed. The path forward is to find the error(s), fix them, and then reprocess the data to see what is really happening. Until then, it is premature, bad scientific form, and yes, 'alarmist' to publish conclusions from processed data that is known to be bad. Any conclusions made before the bugs are worked out of the processing will most likely be wrong.
Tom:
ReplyDeleteMore Gish Gallop I see.
From your Wingham paper, page 1631:
"To determine the change in mass requires knowledge of the density at which the volume changes have occurred. However, of the 21 Antarctic drainage basins included in our survey, we can confidently attribute the fluctuation to changes in ice or snow at only four: basins G–H and E0–E00 have, predominantly, lost and gained ice, respectively, and basins J–J0 and H–J have, predominantly, gained snow."
So their results are based on data from 4 of 21 basins, check.
And from page 1634:
"Even allowing a +-G30 Gt yr-1 fluctuation in unsurveyed areas, they provide a range of -35 to +115 Gt yr-1. This range equates to a sea level contribution of -0.3 to +0.1 mm yr-1 and so Antarctica has provided, at most, a negligible component of observed sea-level rise. In consequence, the data places a further burden on accounting (Munk 2003) for the twentieth century rise of 1.5–2 mm yr-1. What is clear, from the data, is that fluctuations in some coastal regions reflect long-term losses of ice mass, whereas fluctuations elsewhere appear to be short-term changes in snowfall. While the latter are bound to fluctuate about the long-term MAR, the former are not, and so the contribution of retreating glaciers will govern the twenty-first century mass balance of the Antarctic ice sheet."
So, limited control data shows possible losses or gains of snow/ice contributing to possible lowering or rising of the sea level. And specifically stating that the losses are long term while the gains are short term...to put it charitably, underwhelming.
This is indeed the best you've put up in your defence yet. But the data is current only through 2003, and does nothing to counter more current studies like Velicogna 2006 or 2008 (just to throw out a few un-cherry-picked examples).
Yawn,
The Yooper
Louis:
ReplyDeleteSo, you're suggesting an audit of GRACE?
Hmmm, seems familiar...
The Yooper
Does Fuller know the difference between sea ice and ice sheets, and if so when will he retract his conflation of the two?
ReplyDeleteNew York, you seem to be selectively quoting.
ReplyDeleteUm, yeah. NewYork was quoting a different study. Put the link right there in the text and everything
But please, keep complaining about ad homs while talking about "insanity and inanity," and go on accusing others of illiteracy while at the same time totally failing to read their posts. It's comedy gold.
Also: countering one study that claims the Eastern Antarctic has lost 57 billion tons a year–plus or minus 52 billion tons by pointing to another study that claims the Antarctic has gained 27 billion tons a year–plus or minus 29 billion tons? Classic. This is weapons-grade satire… Andy Kaufmann could only have aspired to such at the peak of his talents.
Whoah! from the "cited by" link posted earlier, this:
ReplyDeletehttp://www.springerlink.com/content/b13x0v3726x555g7/fulltext.html
"... The model predicts melting at all ice shelf bases in agreement with observations, ranging from below a meter per year for Ronne Ice Shelf to about 25 m/year for the Pine Island Glacier. In a warming scenario with a one-degree increase of the inflow temperature, the latter glacier responds with a 1.4-fold increase of the melting rate. Other caverns respond by more than a tenfold increase, as, e.g., Ronne Ice Shelf...."
There are obviously a bunch of bright guys posting here, but IMHO, some of you are missing, or glossing over valid concerns about the way GRACE satellite data is processed. Keep in mind this is gravity data from a new satellite. Gravity measurements indicate a loss of mass, which is most likely, (but not necessarily) from a loss of ice.
ReplyDeleteSeveral posters at WUWT correctly point out potential pitfalls with the way the raw data is processed. These are valid scientific concerns that need to be resolved and put to rest before the processed data can be trusted:
1) A fairly simplistic, un-calibrated computer model is used to adjust the satellite data for mantle rebound from the last glaciation ~12,000 years ago.
2) After processing GRACE data from the western Antarctic, the calculated loss of ice was so large that an expedition was sent to verify the numbers. They found that the processed data overestimated ice loss by a substantial amount.
3) GRACE should open their systems and software so that people can see exactly how they are processing the raw data from the instruments.
4) Statistically “manipulated” or “interpolated” data is not “observational data”, and should never be referred to as such.
Clearly, there are errors in the way the data is processed. The path forward is to find the error(s), fix them, and then reprocess the data to see what is really happening. Until then, it is premature, bad scientific form, and yes, 'alarmist' to publish conclusions from processed data that is known to be bad. Any conclusions made before the bugs are worked out of the processing will most likely be wrong.
By Louis' standards there practically is no such thing as observational data about quantities of physical interest. Even a thermometer, after all, is ultimately a model; it measures not temperature but volume of mercury. Sort of. Actually it measures how many notches up a tube the mercury expands to. Assuming you know what an eyeball does. That way lies madness, not science, of course.
ReplyDeleteAs for Louis' other points, they seem identical to the ones made and claimed surmounted in the Wu et al work cited in the posting.
Time for a quotation sanity check.
ReplyDelete"The trouble with the world is not that people know too little, it's that they know so many things that just aren't so.“ -- Mark Twain
"Everyone is entitled to his own opinion, but not his own facts." -- The late Senator Daniel Patrick Moynihan
"Sure, we're driving toward a wall on a foggy night at a high rate of speed, but it might be 30 yards ahead or 100, so why panic and assume it's only 30 yards to impact? The problem, as I pointed out, was that we can't decelerate at anywhere near the desired rate, so it's a difference of hitting the wall hard enough to sustain broken ribs and numerous bad lacerations, or hitting it so hard we wind up with life-threatening injuries." -- Lou Grinzo
Oops, its when the Ross and Weddell seas once again join, right through the heart of WAIS, as had happened not all that long ago.
ReplyDeleteBut please don't let facts about the past influence your thoughts about what the future will bring, despite the fact that CO2 concentrations are now higher than at any time since the Miocene.
By all means concentrate on the here and now, being sure to ignore to difficulties that massive SLR will bring to future generations (if any).
Michael Tobis said:
ReplyDeleteBy Louis' standards there practically is no such thing as observational data about quantities of physical interest. Even a thermometer, after all, is ultimately a model; it measures not temperature but volume of mercury. Sort of. Actually it measures how many notches up a tube the mercury expands to.
Your statement about the thermometer illustrates my point. A thermometer with only notches, and no numbers is nearly useless. Before you can get accurate readings, the thermometer must be calibrated correctly. If, after calibration, you stick it in boiling water, and it doesn't read 100 C or 212 F, then the calibration is WRONG. Therefore, if you draw conclusions from temperature readings taken with an incorrectly calibrated thermometer, they will also likely be wrong.
I stand by my previous statement: Clearly, there are errors in the way the data is processed. The path forward is to find the error(s), fix them, and then reprocess the data to see what is really happening.
Sort of, but the measurement will never be perfect, and the decisions have to be made in a timely way.
ReplyDeleteLouis, attempting to be scientifical:
ReplyDelete> If, after calibration, you stick it in boiling water, and it doesn't read 100 C or 212 F, then the calibration is WRONG.
Residents of Denver will be surprised to learn this.
How are we supposed to distinguish the Cool-It-Kids from those that scream "Teach the Controversy" when it comes to evolution?
Demonstrate that there is more than "the Art of Controversy" to your hand-wringing, by holding yourself to a higher standard of discourse and rigor, while obtaining published results in the same field of inquiry. Or naming practitioners who maintain your high standard.
Will the result be less shabby than what has been produced by intelligent design investigators? Unlikely. Feel free to prove the world wrong.
Mr. Fuller cites the following for support that the ice mass of Antarctica is slightly increasing. Mr Fuller has raised this point as evidence that loss of ice from Antartica is unlikely to contribute much to sea leavel rise in the 21st Century:
ReplyDeleteMass balance of the Antarctic ice sheet
www.cpom.org/research/djw-ptrsa364.pdf
Lets read the conclusion:
We show that 72% of the Antarctic ice sheet is gaining 27G29 Gt yrK1, a sink of ocean mass sufficient to lower global sea levels by 0.08 mm yrK1. The IPCC third assessment (Church & Gregory 2001) partially offset an ongoing sea-level rise due to Antarctic retreat since the last glacial maximum (0.0–0.5 mm yrK1) with a twentieth century fall due to increased snowfall (K0.2–0.0 mm yrK1). But that assessment relied solely on models that neither captured ice streams nor the Peninsula warming, and the data show both have dominated at least the late twentieth century ice sheet. Even allowing a G30 Gt yrK1 fluctuation in unsurveyed areas, they provide a range of K35–C115 Gt yrK1. This range equates to a sea level contribution of K0.3–C0.1 mm yrK1 and so Antarctica has provided, at most, a negligible component of observed sea-level rise. In consequence, the data places a further burden on accounting (Munk 2003) for the twentieth century rise of 1.5–2 mm yrK1. What is clear, from the data, is that fluctuations in some coastal regions reflect long-term losses of ice mass, whereas fluctuations elsewhere appear to be short-term changes in snowfall. While the latter are bound to fluctuate about the long-term MAR, the former are not, and so the contribution of retreating glaciers will govern the twenty-first century mass balance of the Antarctic ice sheet.
(emphasis mine)
I believe that Mr.Fuller has characterized the current state of the data well enough. It is highly uncertain with multiple (and conflicting) lines of evidence that show that Antarctica, on the continental scale, *may* be gaining ice mass. That he is concentrating on those papers which show ice mass gaining is reasonable, since that is his argument. He should not have to argue both sides of the issue. He is not presenting himself as a fair or balanced analyst. He is pursuing a line of argument. But given that he has cited Wingham 2006 in defense of his case, it's interesting that he fails to mention the conclusion of that paper.
Tom, did you deliberately choose to overlook the conclusions of Wingham et al in the paper that *you* cited? Or do you believe that Wingham 2006 supports your contention that Antarctica will contribute little to sea level in the 21st century *despite* their conclusions? Is there some other reason you fail to note the conclusions of the paper that you cited?
---
I see that Daniel Bailey has also noted that the paper Fuller has cited does not support the main thrust of his argument. But I think it is a point worth repeating. :)
Louis: "After processing GRACE data from the western Antarctic, the calculated loss of ice was so large that an expedition was sent to verify the numbers. They found that the processed data overestimated ice loss by a substantial amount."
ReplyDeleteSource, please. You might also want to read this.
Mr. Broberg, I cannot blame you for not having read all of the comments here, but I have said several times that I agree with conventional climat theory that projects ice accumulation in the Antarctic for the first few decades of the 21st Century, possibly helping to balance out melt from other sources.
ReplyDeletePDA: "Um, yeah. NewYork was quoting a different study. Put the link right there in the text and everything"
ReplyDeleteFuller is probably confused because some of the authors are the same, but the study has a different title, a more recent year, and additional authors.
In summary:
1. Most studies of recent observations (last couple of decades) indicate Antarctica is on balance losing sheet ice.
2. One outlier study (Shepherd & Wingham 2006) indicates a small net gain in Antarctic sheet ice over 1992-2003, although losses are within the uncertainty bounds. Their methods use radar altimetry, which is biased towards positive values. Nonetheless, Daniel Bailey posts some key quotes from the study, indicating the gains are primarily from snowfall and losses primarily from retreating glaciers. Since the effects of snowfall are considered to be short-term and retreating glaciers long-term, the authors conclude that retreating glaciers will dominate 21st century changes.
3. A more recent study involving the same authors note that losses to key glaciers has accelerated in recent years, and that they are expected to contribute significantly to global sea level rise this century.
So what might Fuller have left to sling at those big bad "alarmists"? He reminds me of a lawyer defending a hopeless client. 10 witness line up to testify against his client so he dismisses them and finds a witness, who when cross-examined, undermines his case further. Time for him to bust out some random quotes about Antarctic sea ice. Objection - irrelevant information...sustained.
The question at hand, Tom, is whether ice loss from Antarctica will cause long term sea level rise.
ReplyDeleteYou piece at WUWT seems to derides those, like Wingman 2006, who believe that answer to that question is 'yes.'
Do you, Tom, believe that melting ice from Antarctica will contribute to sea level rise in the 21st century?
If yes, how much SLR will melting contribute in your opinion?
If no, why not?
Even though I have read your latest piece at WUWT complete with insulting jabs at Tobis, I was unable to find the answer to these basic questions. Your replies here seem to indicate that you don't believe that there will be long term SLR contributions from AIS, but I won't assume that unless you explicitly state it.
What the IPCC says should be happening: "It is likely that there has been significant anthropogenicwarming over the past 50 years averaged over eachcontinent except Antarctica.
ReplyDeleteClimate changes during the 20th century are estimated from
modelling studies to have led to contributions of between –0.2
and 0.0 mm/yr from Antarctica (the results of increasing
precipitation) and 0.0 to 0.1 mm/yr from Greenland (from
changes in both precipitation and runoff).
Model simulations of this kind have not included the
possible effects of changes in climate during the 20th century.
The simulations described later (Section 11.5.1.1), in which an
ice sheet model is integrated using changes in temperature and
precipitation derived from AOGCM simulations, suggest that
anthropogenic climate change could have produced an additional
contribution of between –0.2 to 0.0 mm/yr of sea level from
increased accumulation in Antarctica over the last 100 years, and
between 0.0 and 0.1 mm/yr from Greenland, from both increased
accumulation and ablation.
For Antarctica, mass-balance sensitivities for a 1°C local
warming are close to –0.4 mm/yr (with one outlier of –0.8
mm/yr) of global sea level equivalent. A common feature of all
methods is the insignificant role of melting, even for summer
temperature increases of a few degrees, so that only accumulation
changes need to be considered.
For CO2 increasing according to the IS92a scenario
(without aerosol), studies by Van de Wal and Oerlemans (1997)
and Huybrechts and De Wolde (1999) calculated sea level
contributions for 1990 to 2100 of +80 to +100 mm from the
Greenland ice sheet and about –80 mm from the Antarctic ice
sheet."
Mr. Broberg, as I said previously, I think ice will accumulate in the Antarctic during the early part of this century.
ReplyDelete> expedition
ReplyDeleteAnother pony-here-somewhere delivery from Mr. F.
Well, let's see
This? http://www.sciencedaily.com/releases/2009/10/091019122838.htm
ScienceDaily (Oct. 20, 2009) — "New ground measurements made by the West Antarctic GPS Network .... suggest the rate of ice loss of the West Antarctic ice sheet has been slightly overestimated.
'Our work suggests that while West Antarctica is still losing significant amounts of ice, the loss appears to be slightly slower than some recent estimates ....'"
Nope, that doesn't come close to F's "substantial amount" description. Anyone got anything?
Mr. F? Got anything?
Tom, Ron asked you a specific question. You copy/pasted the answer to a different question.
ReplyDeleteCare to try again?
http://www.springerlink.com/content/r410j700162342j0/fulltext.html ?
ReplyDeleteDon't think so, but it's a good survey article with a full section citing significant GPS work in Antarctica.
PDA, I'd like to speculate on what your initials actually refer to, but I'll restrain myself.
ReplyDeleteMr. Broberg actually asked three questions, but I guess arithmetic is beneath you.
I actually think if he wants more information he is capable of asking for himself.
However, if you're feeling a bit of prurient curiosity, my answers are:
1. Not through 2030/
2. Maybe 1 mm, maybe less.
3. (In case that counts as 'not'), because I don't think temperatures will climb quickly enough to cause more, obviously.
With that, I'll bid this thread adieu until the next time Tobis decides to lie about me. Which won't be long--I get slimed about once a week here, it seems.
But I guess it keeps dhogaza happy.
Ron: Do you, Tom, believe that melting ice from Antarctica will contribute to sea level rise in the 21st century?
ReplyDeleteTom: Mr. Broberg, as I said previously, I think ice will accumulate in the Antarctic during the early part of this century.
Is that a 'no'?
Do you agree or disagree with the conclusion of Wingham 2006 that Antartica ice loss at the edges will dominate ice gain in the interior during the 21st century?
Tom:
ReplyDeleteAll your cites thus far have either been misquoted or taken out of context (i.e., they don't say what you think they say), or have been dated and not reflective of the latest studies and consensus of thinking. And when called on it, you have ignored those calling you out.
I'm minded of the story of a teenage boy, full of bluster and bravado, who draws a line in the sand & dares another to cross it. And when the line is crossed, backs up, draws another line & repeats the dare. Kind of like this one, but not as humorous.
Been an entertaining day; I thank you for your part in that.
Not as unbelievable as those Climate Progress and Real Climate threads I participated in in which Curry imploded, but a wreck nonetheless. Less horror and more funny zombies.
That reminds me, the new Resident Evil:Afterlife movie comes out this week! Bonus!
The Yooper
Surely a respectable author wouldn't blow off a request for a cite?
ReplyDeleteThis? http://www.sciencedaily.com/releases/2009/10/091019122838.htm
"... while West Antarctica is still losing significant amounts of ice, the loss appears to be slightly slower than some recent estimates ....'"
doesn't come close to F's claimed "substantial amount" that he found somewhere.
Mr. F? Got a cite? What's your trusted source for that?
It's been great sport but is accomplishing nothing further.
ReplyDeleteI agree with Fuller on one thing at least. Let's put this thread to bed.