Ross Ice Shelf melt and other cool fables

Ross Ice Shelf

Rob Fenwick, in Accelerating melt reason to worry (The Press, 21 May 2012), launches into a worry-fest about all the fabulous calamities said to be on the way with “continued” man-made global warming.

The astute reader will know that the word “fabulous” is derived from “fable”. It means unreal or imagined more than it means magnificent. I chose that word because all the disasters Mr Fenwick briefly catalogues are fantastic (cf. “fantasy”). But I should begin at the beginning of his niggle-gala. He says:

When the world’s polar scientists gathered in Montreal last month – all 3000 of them – it seemed like a case of preaching to the choir.

After 20 years of intense study of the effects of changing climate conditions at the poles, there is certainly no longer any debate over what is going on.

The ice sheets in Greenland and West Antarctica are melting, oceans are rising and acidifying, ecosystems are struggling to adapt. No-one can argue with the facts.

First, I am astounded that he claims that no debate took place at a conference. Those events are exactly where debate is most likely. They are arranged in the expectation of debate, designed to encourage debate, people go along anticipating debate and the organisers try to provide the very best means of managing debate (it’s the same with Caribbean fishing competitions — they try to manage de bait).

But he says there was no debate — the conference must have been a dismal failure, no better than a long lecture, and that’s hard to accept. Does he expect us to believe that, among 3000 scientists, none disagreed with any other? It implies that, astonishingly, not one of them even had an ego.

Second, it’s disappointing to hear this, because I have studied climate change for over eight years and I know that scientists differ on some vital features of climate change, yet he ignores them all.

Rob Fenwick is a leader in polar science and scientific management, and as a director of CarbonZero he makes money from the faddish measuring of carbon footprints, inspired by the story that humans are responsible for global warming. So it’s fair to assume that he is acquainted with some of the details of polar science and global warming. The reasonable conclusion therefore is that he has wilfully ignored them. Let me explain.

There are uncertainties, unknowns and there are strong disagreements on many aspects of global warming. Yet he says:

there is certainly no longer any debate over what is going on. The ice sheets in Greenland and West Antarctica are melting, oceans are rising and acidifying, ecosystems are struggling to adapt. No-one can argue with the facts.

But the ice sheets are not melting. 21st-Century Evolution of Greenland Outlet Glacier Velocities (Moon et al., 2012) reports Greenland glacier acceleration this century that indicates that “sea level rise from Greenland may fall well below proposed upper bounds.” The great Antarctic and Greenland ice sheets are not melting and even if they were, they would take hundreds of years to vanish.

Mr Fenwick mentions the Ross Ice Shelf, citing the depth of it as 750 metres. It actually measures about 330 metres at the ice front (out in the ocean), which is an astounding thousand feet down into the water. Closer to the land, where it rests mostly on the sea bed, it deepens to more than 800 metres — 2600 feet of solid ice. It’s enormous.

I calculated it contains something like 240 trillion tonnes of super-dense ice. I’m happy to share the calculations of that, but that slab of ice isn’t going anywhere in a hurry, whether as ice, water or vapour. Human emissions of CO2 are about 4% of the natural flux — 30 gigatons added to a natural 750 gigatons.

So we expect 30,000,000,000 tons of gas to melt 240,000,000,000,000 tons of ice at an average temperature well below freezing — yeah right. Anyone who fears that gargantuan glob of ice could be melted by our dainty emissions of carbon dioxide is pushed for entertainment.

Sea ice in the Antarctic (as Mr Fenwick must know) has been growing for the 30 years of satellite observation and in the Arctic has been recovering since the one-off record decline five years ago.

Yes, oceans are rising, but at the same steady and unremarkable rate as for the last 6000 years. Sea levels increased during the 20th Century by about 185mm and recent papers report no acceleration. For all the excitable chatter about Pacific islanders becoming homeless and evacuating to New Zealand, none of that has happened and the South Pacific Sea Level and Climate Monitoring Project run by the Australians continues to report it has nothing to report.

Ocean acidification is not a matter for concern. He should know that the oceans are still robustly alkaline. Acidification is minor, limited in extent, the effects on biota are hotly disputed, though many are beneficial, and the magnitude of predicted acidification is almost entirely a matter of guess-work.

The widely-available ocean maps showing regions of declining pH reveal that, as in the eastern equatorial Pacific, lowered pH is probably caused mainly by upwelling bottom water, not absorption from the atmosphere. There are also numerous sites where carbon dioxide bubbles naturally from the ocean floor and the ecosystems adapt.

Oceanic bottom water has slightly elevated pH due to higher levels of dissolved carbon dioxide. When it’s only just above freezing, water dissolves an enormous amount of CO2, which is available in abundance from the dead bodies constantly raining down. When that water surfaces and warms, it releases CO2 which feeds plankton and other plant life.

Chemists among the polar scientists will confirm that as oceans heat up from any cause, the dissolved carbon dioxide will outgas, instantly reversing any recent acidification caused by absorbing more CO2 from the slight anthropogenic increase.

Ecosystems may struggle in future to adapt if the wilder fancies of computer models are realised. But they’re certainly not struggling now, for the simple reason that there’s been no uncharacteristic warming.

Of the Ross Ice Shelf, Mr Fenwick says it is “not yet showing signs of significant, unseasonal melt.” As he cannot point to observations of dangerous change, he simply speculates. See how cleverly he leaves the impression that he’s making predictions.

What will cause the Ross Ice Shelf to melt?

When will it start and how fast will it be?

How will it affect the Pacific Ocean, New Zealand and its Pacific neighbours?

What should we be doing now to try to slow it down and prepare for it?

But he gives us no evidence for his outlandish suggestion that the ice shelf will melt.

So then he says, almost as though he heard me getting worried: “However, researchers are puzzled by unusual pulses of warm southern ocean currents that are circulating around Antarctica and which, in other parts of the continent, are starting to melt ice from below.”

The simple fact is that those “unusual pulses” are nothing more than natural current fluctuations. For what else, in heaven’s name, might they be? What is he trying to alarm us with? The ice has been floating in the Southern Ocean for thousands, nay, millions of years. It comes and it goes, waxes and wanes. Don’t panic, Rob!

Now he imagines what might happen IF it melted. Because to replace reality we must construct a dream.

If the Ross Ice Shelf starts to melt, its affect [sic] on the Pacific Ocean both physically and chemically, and its impact on the economies of our Pacific Island neighbours, will be catastrophic.

He doesn’t say what would cause that but I guess the effect would be even worse when it finished melting. Hundreds and hundreds of years later.

And even if all of these things were true, there’s still no evidence that we caused them. There’s still no reason to change what we’re doing, unless it is causing real environmental harm.

One of his statements is almost true: no-one can argue with the facts — except Rob Fenwick.


Rob Fenwick is chairman of Antarctica New Zealand and a former chairman of the Antarctic Heritage Trust. In 2005 the New Zealand Geographic Society named the Fenwick Ice Piedmont in the Ross Sea for his work in Antarctica.

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Andy
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Andy

3000 people get together. They all agree about everything.

How does this differ from a religious revivalist meeting?

Bob D
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Bob D

How will it affect the Pacific Ocean, New Zealand and its Pacific neighbours?

Easy – it won’t. If it “melts” it will have zero effect on sea levels. Ice shelves, by definition, float.
Archimedes.
QED.

Bob D
Guest
Bob D

(it’s the same with Caribbean fishing competitions — they try to manage de bait)

That hurt.

Andy
Guest
Andy

In 2005 the New Zealand Geographic Society named the Fenwick Ice Piedmont in the Ross Sea for his work in Antarctica.

It seems quite appropriate that he gets a feature named after him that by his own predictions will disappear in due course.

Richard Treadgold
Guest

You’re right, but, to be fair, there could be some effect. If the melt is swift, there might be dilution by fresh water (though doing what, exactly?), and a fair proportion of the shelf is grounded, so there could be a contribution to sea level rise. But it will be far in the future so there’s surely time to adapt.

Richard Treadgold
Guest

Thank you, thank you.

Alexander K
Guest
Alexander K

To reiterate my opinion from an earlier post, the gentleman in question (and I use the term very loosely) is a self-aggrandising opportunist of the first water who has more in common with revivalist preachers that star on and own bad-taste religious TV channels in the USA, selling religion’s version of snake-oil. While the gullible abound, so will such creatures who prey on them.
As someone once said, ‘A lie gets halfway around the world before Truth gets it’s boots on.’

Richard Treadgold
Guest

That’s a damn strong opinion, Alexander. Bad-taste preachers? Whatever happened?

PeterM
Guest
PeterM

The Václav Klaus talk at Heartland is worth reading. He understands the socialist mindset.

Also of interest is

‘Media liaison staffers have been sent to an international polar conference in Montreal to shadow Canadian government scientists during interviews, in what critics are calling the latest example of extreme information control by the Harper Conservatives’.

http://www.cbc.ca/news/canada/montreal/story/2012/04/24/scientists-muzzling-canada.html

Alexander K
Guest
Alexander K

Richard, you are damned right it’s a strong opinion! I have been in the position of trying to unpick some of the damage such people do even here in NZ.
I have no problems with religion per se, and know that millions of people have some sort of religious belief which they find helpful in their attempts to live morally and ethically ‘good’ lives, but when Man’s religious urge is misused by opportunists and con-men, they do make me more than a little angry.

Richard C (NZ)
Guest
Richard C (NZ)

“The ice sheets in Greenland and West Antarctica are melting”

Do they still only melt at and above O C or has the change of state changed? Even if it has I don’t see steams of melt water coming off the surface.

I suspect too that those figures are not attired for Caribbean fishing.

“….oceans are rising”

A team of researchers reports in Nature Geoscience that land-based water storage could account for 0.77 millimetres per year, or 42%, of the observed sea-level rise between 1961 and 2003. Of that amount, the extraction of groundwater for irrigation and home and industrial use, with subsequent run-off to rivers and eventually to the oceans, represents the bulk of the contribution.

http://www.nature.com/news/source-found-for-missing-water-in-sea-level-rise-1.10676

Kinda leaves anthro SLR out in the cold (Ha!).

At least Rob Fenwick has a hobby.

Mike Jowsey
Guest
Mike Jowsey

The astute reader will already know that manmade global warming is so last year.

Gary
Guest
Gary

Having had Rob Fenwick as a neighbour I can tell you that his carbon foot print is far greater than the average man. If there is money to be made Rob will be into it.
Rest assured he is a spin doctor, just another Al Gore seeing what he can rent seek.

Nick
Guest
Nick

Hi Richard T,
Moon et al. 2012 shows that glacier melt in Greenland is accelerating. The rate is slower than the theoretical upper limit upper limit from ice shelf dynamics but how you get from accelerating but less than the worst case scenario to “ice sheets are not melting” seems like a bit of a leap. Can you clarify your reasoning here please?

Bob D
Guest
Bob D

Nick, AR4 says (emphasis added): The present SMB of Greenland is a net accumulation estimated as 0.6 mm yr–1 of sea level equivalent from a compilation of studies (Church et al., 2001) and 0.47 mm yr–1 for 1988 to 2004 (Box et al., 2006). …Sufficient warming will reduce the SMB to zero. (SMB is surface mass balance.) This is reinforced by the following papers: H.J. Zwally et al, Growth of the Southern Greenland Ice Sheet, Science 281, 1251 (1998). They found an ice sheet thickening rate of about 5 cm/year. C. H. Davis, C. A. Kluever, and B. J. Haines, Elevation Change of the Southern Greenland Ice Sheet. Science 279, 2086-2088 (1998). They found a small increase (1.5 cm/year) over the period 1978-1988. R. Thomas et al, Mass Balance of the Greenland Ice Sheet at High Elevations. Science 289, 426-428 (2000). They find that “On average, the region has been in balance”. O. M. Johannessen, K. Khvorostovsky, M. W. Miles, and L. P. Bobylev, Recent Ice-Sheet Growth in the Interior of Greenland. Science 310, 1013-1016 (2005) – They used satellite altimetry over the period 1992-2003, and found the “spatially averaged increase is 5.4… Read more »

Nick
Guest
Nick

Hi Bob D,
Just to be clear,
1 – Do you agree that Moon et. al 2012 shows glacier speeds are accelerating?
2 – How do you reconcile this with Richard T’s claim that Moon et. al 2012 shows “ice sheets are not melting”?

Thanks

Richard Treadgold
Guest

I was perhaps incautious in picking Moon et al. from a bunch of references. My intention was to show a recent retreat from the strident claims of alarm over ice cap melting. Sorry, I chose entirely the wrong reference.

But even Moon et al. don’t claim that the Greenland glaciers are actually melting. Ice caps are too cold to melt and the mass balance is determined more by precipitation, ablation and velocity of outlet glaciers. Such velocity is not increased or reduced by melting except perhaps at the base, at temperatures well below freezing and nothing to do with atmospheric temperatures or even insolation. I’m still searching, but I’m pretty sure the ice caps are not generally considered to have a greatly negative mass balance.

Anyway, that was my thinking.

Bob D
Guest
Bob D

Nick, 1 – Do you agree that Moon et. al 2012 shows glacier speeds are accelerating? Moon et al. show that some are, some aren’t. It’s highly variable, driven by complex processes (“…numerous observations indicate that the trigger for the majority of dynamic thinning in Greenland during the last decade was episodic in nature…”). Certainly it is incorrect for anyone to suggest they are all accelerating due to global warming. 2 – How do you reconcile this with Richard T’s claim that Moon et. al 2012 shows “ice sheets are not melting”? They aren’t melting anyway, as Richard rightly points out. Please show me in the text of Moon et al. where they state the Greenland glaciers are “melting”. Glaciers flow like rivers – you can think of them as giant rivers of ice. Precipitation in the interior flows slowly outward, just like a slow-motion river, driven by the great mass of ice in the centre. They don’t “melt”, except at the very edges where they meet the sea, or fall to low altitudes where it’s warmer. Ablation occurs too, of course. Often the sheet extends out over the ocean as a shelf,… Read more »

Nick
Guest
Nick

Hi Richard T,
Thanks for explaining your error, I appreciate your candor. I think we (and Bob D) have some common ground here saying mass balance is the only real measure total of ice loss.

So maybe we should start with what appears to be the latest research. Jacob et al, 2012 use the GRACE satellites mass measurements to determine that “Glaciers and Ice Caps (GICs), excluding the Greenland and Antarctic peripheral GICs, lost mass at a rate of 148 ± 30 Gt yr−1 from January 2003 to December 2010”. This certainly this seems to show that the ice sheets are melting.

Nick
Guest
Nick

By the way Bob how much of your response is cribbed from here?

https://sites.google.com/site/globalwarmingquestions/ar4green

Have you actually read any of the abstracts for these papers? You might want to be a bit more careful because the paper you cite.

H.J. Zwally et al, Mass changes of the Greenland and Antarctic ice sheets and shelves and contributions to sea-level rise: 1992-2002

Shows a net loss of mass in the ice sheets. Some might even go so far as to say it shows that ice sheets are melting.

Please try to continue this discussion in good faith, dumping loads of papers copied from someone else’s analysis of a different topic is just wasting all our time.

Richard Treadgold
Guest

Does that represent a trickle or a flood? I’m trying to give it some context but I completely stuffed up the arithmetic so I’ll try again in the morning. The other day I worked out that Antarctica’s ice cap is about 24.0 × 1013 tonnes. Greenland’s is given in Wikipedia as 2.85 million km3, or 2.85 × 1015 m3. The glacial ice density I used for Antarctica is 850 kg/m3. What is the combined mass of the two ice caps?

Perhaps some kind soul will have the answer ready for me tomorrow.

Bob D
Guest
Bob D

By the way Bob how much of your response is cribbed from here? The references I gave were nicely laid out on that site, which is why I used the summary instead of typing the same stuff over again. Usually, all we get from warmists are links to Skeptical Science, I try to include text instead. …Have you actually read any of the abstracts for these papers? You might want to be a bit more careful because the paper you cite [Zwally (2005)] shows a net loss of mass in the ice sheets. Drivel, it doesn’t. How can you get it so wrong? Have you read the paper yourself (I have a copy if you’d like one)? It says quite plainly: The Greenland ice sheet is thinning at the margins (–42±2Gt a–1 below the equilibrium-line altitude (ELA)) and growing inland (+53±2Gt a–1 above the ELA) with a small overall mass gain (+11±3Gt a–1; -0.03mma–1 SLE (sea-level equivalent)). Which is exactly the number given: 11 Gigatons every year. That’s a lot of tons. And again in the conclusions: The small mass gain in Greenland is contrary to the widely held view that Greenland is… Read more »

Richard Treadgold
Guest

Whew. I don’t know how you keep your cool, my friend.

Nick
Guest
Nick

We seem to have our wires crossed. I understood Richard was referring to all the ice sheets when he said “The great Antarctic and Greenland ice sheets are not melting and even if they were…” The paper you referenced shows Antarctic ice loss of 47Gt/yr so the net loss is 36Gt/yr. If you have taken offense I certainly apologise but perhaps we can stick to the subject of net ice loss as Richard originally defined it?

Nick
Guest
Nick

Richard T,
I’m not sure what percentage 150Gt is of the total ice sheet mass but is suspect not a lot. But 150Gt/yr of ice sheet loss is approximately 0.04mm/yr of sea level rise, which looks pretty trivial.

Unfortunately this neglects accelerating ice sheet loss as measured by:

Velicogna, I. (2009), Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE, Geophys. Res. Lett., 36, L19503, doi:10.1029/2009GL040222

To be about 56Gt/yr with net ice loss in 2009 of 532Gt/yr.

My quick calculations extrapolating Veliconga’s trend would equate to about a 78cm sea level rise by 2100 from ice sheet melt alone, at which point the sea level would be rising at about 15mm or 5,628Gt per year. I’m slightly surprised at how large this is so if anyone else wants to have a go at the calculation please do so.

Bob D
Guest
Bob D

My apologies, Richard and Nick. I’ve just been dealing with Rob Taylor, who wouldn’t know a fact if he walked into it on a clear day, so I’m losing patience with some of the warmists who just insult, nit-pick and refuse to see the truth of things, constantly moving the goalposts.

If you’re genuinely interested in the science, Nick, then by all means press on, and I’m sure we’ll find some common ground. But if all you want is to score cheap points, then talk to the others, I’m out.

Bob D
Guest
Bob D

Nick, be careful of GRACE. It’s brand-new technology, and is at odds with all the current literature on this subject. Recently they found significant errors in their method and had to revise their numbers – we covered it here on CCG, you’ll have to search for it I’m afraid, I don’t have time. Basically GRACE uses a baseline geoid for their “calibration”, and it was in error.

I believe the same geoid is used for the satellite sea level measurements, and may explain (purely my speculation) the discrepancy between the satellite and tide gauge measurements around the world.

Nick
Guest
Nick

Hi Richard and Bob, to recap, do you have any evidence for your claim that ice sheets (Greenland AND Antarctic) are not melting? I think we agree that the preferred metric is mass balance.

Perhaps we could concentrate on what is currently happening rather than dragging papers from 10 years ago into it. If anything showing that there was no melting a decade ago supports contention that current ice sheet loss is accelerating.

I’m not trying to score cheap points here, I’m just trying to understand the evidence behind your position so that I can clarify my own understanding. If you have problems with GRACE then I’m happy to look at another data set but I do think we have to concentrate on ice sheet loss of both Antarctica and Greenland.

Richard C (NZ)
Guest
Richard C (NZ)

Nick what is the anthropogenic component of ice sheet melt assuming they are? And what is the evidence (i.e. a verified mechanism – hopefully there’s a solid physical basis for it unlike the IPCC’s vagueness/guessing on a radiative SLR effect)? Isn’t the current situation just a drop in the bucket? I ask this because it’s not as if ice sheets have not melted before – after spectacular growth:- 18,000 years ago ice sheets covered large areas of land [See plot and Click for Animation] The growth of the ice sheets began about 120,000 years ago as ice built up on the continents in the Northern Hemisphere, especially in Canada and Europe. The largest extent of these ice sheets occurred 18,000 years ago. At that time the largest ice sheets were between 3.5 and 4 km thick. In North America the largest ice sheet was the Laurentide Ice Sheet centered on Hudson Bay with other sheets centered on Greenland and in the Canadian Rocky Mountains. As these ice sheets expanded they grew together, covering Baffin Bay and eventually the Great Lakes and New England. In northwestern Europe the Fennoscandian Ice Sheet began to grow… Read more »

Bob D
Guest
Bob D

Nick: Greenland’s mass balance is increasing, as is the bulk of Antarctica (ie: the East). In the western area (mainly the peninsula), there is a decreasing mass balance. The reasons seem mainly to relate to changes to the regional ocean currents rather than warmer air. I don’t think the processes are fully understood yet in this region, I’d be interested in any papers you have that clearly explain what’s happening, and why the same isn’t happening everywhere else. This decreasing mass balance is greater than the increasing Greenland and East Antarctica mass balances. AGW theory has long held that the polar regions would display the greatest increase in warming. The loss of Arctic sea ice is well-known, but it has of course no effect on sea levels. The main sea level rise scare has always been two-fold: thermal expansion and ice sheet/glacier loss. Regarding just the ice sheet loss, the increasing mass balance of Greenland puts paid to the Arctic ice component (there are no other significant ice sheets in the Arctic) and the bulk of Antarctica is also increasing in mass balance, so there’s no danger there, so once again the main… Read more »

Nick
Guest
Nick

Hi Richard and Bob, sorry if this all seems a bit labored, I just want to see what areas of common ground and understanding we have before we get into more difficult discussions. We largely agree, I think, that the net mass balance of the ice sheets is decreasing which shows a loss of ice, either through melting or ablation. The effect on sea levels is the same either way. I also think we agree that East Antarctica and Greenland had small mass gains in the period between 1992 and 2002. This was offset by the larger mass loss in West Antarctic as shown by H.J. Zwally et al 2005, Mass changes of the Greenland and Antarctic ice sheets and shelves and contributions to sea-level rise: 1992-2002 Which Bob cited earlier. What interests me and I think is more relevant to your claims that the ice sheets are not melting is what has happened since then. Bob has indicated that he believes that the GRACE data is questionable so lets look at what H.J Zwally has published since his paper in 2005: H.J. Zwally et al 2011 Greenland ice sheet mass balance: distribution… Read more »

Nick
Guest
Nick

You may also want to consider:

Rignot, E., J. E. Box, E. Burgess, and E. Hanna (2008), Mass balance of the Greenland ice sheet from 1958 to 2007, Geophys. Res. Lett., 35, L20502, doi:10.1029/2008GL035417.

Which shows accelerating ice loss of 267 Gt/yr on the Greenland ice sheet in 2007.

Bob D
Guest
Bob D

Nick, On the Zwally (2011) paper, there are some things to consider immediately: 1) Two different techniques (ERS radar and ICESat laser altimetry) are used to compare two different periods (10 and 4 years). While it is of interest, it simply isn’t valid to draw conclusions from this sort of analysis, and as I mentioned before, extrapolating a short period of 4 years forward over a century is never valid. 2) The interior of Greenland continues to thicken. Over the 4-year period 2003-7, however, the edges thinned faster than the centre thickened, leading to an overall decrease in mass balance. This is entirely consistent with the general known reduction in Arctic sea ice loss during this period. However, the Arctic sea ice has since recovered, and it is equally possible that the Greenland low altitude thinning has reduced to previous levels, possibly restoring the positive mass balance, or reducing it to zero. Again, the short period of 2003-7 tells us little about this. 3) The edge thinning was by no means uniform. The SE and N regions showed no thinning (in fact the SE region increased), while other thinned greatly. Once again, this… Read more »

Bob D
Guest
Bob D

Which shows accelerating ice loss of 267 Gt/yr on the Greenland ice sheet in 2007.

See comments above regarding 2007 and short time periods.

Nick
Guest
Nick

Bob,
I’m happy to leave predictions of future ice loss or sea level rise and attributions of the cause out of this. Richard asked a question about trying to get the numbers into context and I tried to help.

While we clearly disagree on the causes and future predictions for ice loss, from your comments above can I take it that you agree that the current science shows that ice sheets, both Greenland and Antarctic, are losing ice rather than “not melting” as you and Richard originally claimed?

Btw I’m not particularly worried about getting my story straight with any particular group. I’m just interested in figuring out what is going on by reviewing the known science and I certainly appreciate you assistance with this.

Richard C (NZ)
Guest
Richard C (NZ)

‘….from your comments above can I take it that you agree that the current science shows that ice sheets, both Greenland and Antarctic, are losing ice rather than “not melting” ” Nick, why do you make no attempt to read, absorb, assimilate, comprehend, understand, analyze and generally extract the key specifics of what has been put before you? Is it your position that Bob’s rundown of the issues is of no consequence to you because you want to dumb down the argument in typical warmist fashion into a nice simple story line so that any contrary argument to your foregone conclusion is wasted effort. You respond with a simplistic, abstracted, generalization of those uncertainties and differentiations of the observed counteracting phenomena at various locations that immediately alerts that you have no intention of actually entertaining anything other than what you have decided is what everyone should “agree” to i.e. your opinion stands no matter what. You wont get much agreement from that approach here. Suggest a quick scan of ‘Climate Science and the Uncertainty Monster’ by J. A. Curry and P. J. Webster for some perspective http://journals.ametsoc.org/doi/pdf/10.1175/2011BAMS3139.1 Uncertainty Lexicon The nature of uncertainty… Read more »

Bob D
Guest
Bob D

Nick, I must say I agree with Richard C here. Either step up with some science or retire gracefully. I’ve seen no actual scientific discourse from you, you haven’t actually responded in any way to any of the points I or Richard C have made, you just keep re-stating your position and claiming we agree or disagree with it, despite the paragraphs of text I’ve written above discussing the science itself. You say: …from your comments above can I take it that you agree that the current science shows that ice sheets, both Greenland and Antarctic, are losing ice rather than “not melting” as you and Richard originally claimed? No you cannot. As I have explained at some length above, a short 4-year trend bang in the middle of a known downward spike in the Arctic sea ice does not prove that Greenland is losing ice to any great degree, certainly not enough to undo the decades of ice build-up previously. Remember too that all experts agree that Greenland has significantly more ice now than it did in the 1930s and 40s. And also during the MWP. As for Antarctica, the bulk of… Read more »

Richard C (NZ)
Guest
Richard C (NZ)

Also, it is entirely possible for the Greenland ice sheet to be losing ice but “not melting”. Glaciers flowing to the sea are by definition: ice forming where accumulation of snow exceeds melting. Howat et al 08 found that nearly 75 percent of the loss of Greenland ice can be traced back to small coastal glaciers. Melting occurs at the melt zone EVERY summer. From NASA Earth Observatory:- [See melt zone image http://eoimages.gsfc.nasa.gov/images/imagerecords/5000/5597/greenland_tmo_2005165.jpg%5D In this image, the melt zone appears along the western edge of the ice. In this zone, water has saturated the ice, darkening its color from white to blue-gray. The colored lines indicate the approximate melt zone extents for June 2001 through June 2005. Between June 2001 and June 2003, the melt zone increased substantially, then shrank somewhat in June 2004. The melt zone for June 2005 appears roughly equivalent to that of June 2002, the same year that later set a record in Greenland Ice Sheet melting. These images show the Greenland Ice Sheet midway through the seasonal melt. Summer melting generally extends from the spring through the early fall. http://earthobservatory.nasa.gov/IOTD/view.php?id=5597 That is, the melt zone RECOVERS each year… Read more »

Bob D
Guest
Bob D

See Howat (Science 2007):

Greenland was about as warm or warmer in the 1930’s and 40’s, and many of the glaciers were smaller than they are now. This was a period of rapid glacier shrinkage world-wide, followed by at least partial re-expansion during a colder period from the 1950’s to the 1980’s. Temperatures indeed were warmer in the 1930s and 1940s in Greenland. They cooled back to the levels of the 1880s by the 1980s and 1990s before resuming a rise in the middle 1990s. The recent warming is not yet at the same level as that of the 1930s and 1940s.

Richard Treadgold
Guest

apart from the Antarctic peninsula which is losing it.

So readers understand, the last thousand kilometres of the much-discussed Peninsula isn’t even part of the Antarctic, as it protrudes out of the Antarctic Circle into the normal world that sees the sun every day of the year. It’s hardly surprising there’s evidence there of some warming.

Nick
Guest
Nick

Thanks to everyone for the carefully considered responses.

Bob D what do you consider to be the “relevant climatic timescales”? I was expecting about 15 years but feel free to correct me if you had something different in mind.

Richard C (NZ)
Guest
Richard C (NZ)

Here’s summer melting for the entire Greenland ice sheet from the 2011 Arctic Report Card (ARC): Year 2011 is 6th for melting, after 2010, 2007, 1998, 2002, 2005 http://www.arctic.noaa.gov/reportcard/greenland_ice_sheet.html [The 2011 update at this link will be superseded by the 2012 update and 2011 goes to ‘Previous Arctic Report Cards’ see below].

I note:-

“A dominant source of energy for melting is absorbed solar irradiance, which depends on the surface solar reflectivity from ~0.3 µm to ~4 µm in wavelength, known as the albedo” […] “Negative albedo anomalies are widespread over the ice sheet during the 2011 melt period”

The Inconvenient Skeptic has compiled Mass Accumulation and SMB graphs from 2010 ARC and Wake (going back 150 yrs) here http://theinconvenientskeptic.com/2010/12/mass-accumulation-of-greenlands-ice-sheets/ (not vouching for their veracity). Quoting:-

“If only the last 8 years are looked at (like SkS) it appears that the recent behavior is abnormal. If a longer period is looked at it is clear that such behavior appears to happen in cycles.”

Previous Arctic Report Cards http://www.arctic.noaa.gov/reportcard_previous.html

Bob D
Guest
Bob D

Nick, Bob D what do you consider to be the “relevant climatic timescales”? I was expecting about 15 years I’m not sure to be quite honest. Most of the statements I’ve read seem to consider 15 years to be a minimum, but I suppose it depends on what you’re measuring. For example, it may be valid to use 10 years of data if the trend is statistically significant, but then the question arises: have we used a long enough period to exclude natural periodicity? What I mean by that is: take for example the PDO. We know that every 60 or so years there is a naturally-occurring cycle in world temperatures. Any 15-year period within that is quite likely to produce a significant trend, but if we ignore the larger cycle, we make fools of ourselves, as we saw happening in the 1970s (cooling scare) and in the 1990s (warming scare). It’s like taking a trend within a sine wave, and trying to draw conclusions from it. One moment it’s up, the next it’s down! And on top of those cycles there are even longer cycles, for example every 1,000 to 1,500-odd years.… Read more »

Richard C (NZ)
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Richard C (NZ)

If you use ARC (Greenland), 15 yrs gives small gain then loss http://theinconvenientskeptic.com/wp-content/uploads/2010/12/ARC-Accum-550×370.png

Wake shows similar but pronounced loss for the same 15 yr period http://theinconvenientskeptic.com/wp-content/uploads/2010/12/Wake-Accum-550×370.png\

ARC 1958 – 2010 gives loss – gain – loss but not yet back to 1970 level at 2010. Wake 1866 – 2005 gives gain – loss.

In terms of CO2, the last 15 yrs is hardly the relevant climatic timescale. The CO2 uptick started around 1950, that’s 60 yrs. of supposed influence.

See this comment https://www.climateconversation.org.nz/2012/05/ross-ice-shelf-melt-and-other-cool-fables/#comment-96710 re ARC and Wake.

Nick
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Nick

Hi Bob,
You say “on relevant climatic timescales, Greenland and Antarctica are gaining ice, apart from the Antarctic peninsula which is losing it.” but if you are not sure what the relevant timescale is how do you know that Greenland and Antarctica are gaining ice?

Nick
Guest
Nick

Bob and Richard T, recent research shows that ice loss in West Antarctica extends far beyond the Antarctic peninsular and well into the Antarctic circle.

Rignot et al 2008. Recent Antarctic ice mass loss from radar interferometry and regional climate modelling. Nature Geoscience

“In East Antarctica, small glacier losses in Wilkes Land and glacier gains at the mouths of the Filchner and Ross ice shelves combine to a near-zero loss of 4±61 Gt /yr. In West Antarctica, widespread losses along the Bellingshausen and Amundsen seas increased the ice sheet loss by 59% in 10 years to reach 132±60 Gt /yr in 2006. In the Peninsula, losses increased by 140% to reach 60±46 Gt /yr in 2006.”

Nick
Guest
Nick

Bob, Rignot et. al 2008 refered to above covers 50 years (the clue is in the title). They say

“We find that the ice sheet was losing 110 ± 70 Gt/yr in the 1960s, 30 ± 50 Gt/yr or near balance in the 1970s–1980s, and 97 ± 47 Gt/yr in 1996 increasing rapidly to 267 ± 38 Gt/yr in 2007.”

I’m not sure what you consider to be a “short time period” but Rignot et al. basically show 50 years where the Greenland mass balance was not increasing and shows accelerating ice loss since 1977.

Richard C (NZ)
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Richard C (NZ)

Completely contradicts ARC (annual update) and Wake, see this comment https://www.climateconversation.org.nz/2012/05/ross-ice-shelf-melt-and-other-cool-fables/#comment-96716 and this comment https://www.climateconversation.org.nz/2012/05/ross-ice-shelf-melt-and-other-cool-fables/#comment-96710

Does Rignot chronicle the years that gained too? If not, loss only is only half the story.

Richard C (NZ)
Guest
Richard C (NZ)

Paper finds Greenland unlikely to melt from climate change

http://hockeyschtick.blogspot.co.nz/2012/05/paper-finds-greenland-unlikely-to-melt.html

Knud Rasmussen pictures: Greenland is melting less quickly than 80 years ago

http://motls.blogspot.co.nz/2012/05/knud-rasmussen-pictures-greenland-is.html

Nick
Guest
Nick

Hi Richard, can you be more specific about how Rignot contradicts ARC?

ARC says:

“Rignot et al. (2011) find an acceleration of Greenland ice sheet mass budget deficit during 1979-2010, in close agreement with an independent mass balance model.”

So I would be surprised if they completely contradict each other as you claim.

Rather than asking me what Rignot (2008) says perhaps you could read it yourself. Here’s a link for your convenience

ess.uci.edu/researchgrp/erignot/files/RignotetalGRL2008GL035417.pdf

While Greenland may not melt completely if the temperature rises 5C to the level 125,000 years ago I do note that the sea levels were 5m higher at that time. That is quite a lot.

If the entire Greenland ice sheet melted sea levels would rise by 7.2 meters from this alone not including contributions from the Antartic ice sheet or thermal expansion. I’m not saying that this is likely to happen, I’m just trying to put into perspective the effects of even partial melting.

You seem to have misrepresented the Knud Rasmussen pictures. The article state

“…the average rate of retreat (in meters per year) is higher today than it used to be…”

So if anything the evidence shows a higher rate of melting than 80 years ago.

Richard C (NZ)
Guest
Richard C (NZ)

I’ll start with the Knud Rasmussen pictures to clear up your own misrepresentation Nick. The full quote from Motl’s article is:- The pre-satellite pictures of ice shelves are rare. One may evaluate them in various ways. For example, 55% of the retreating glaciers were retreating at a faster rate 80 years than in recent years. On the other hand, the average rate of retreat (in meters per year) is higher today than it used to be because there are some isolated very quickly retreating glaciers today. So whether the retreat of Greenland’s glaciers was faster 80 years ago than today may depend on the detailed specification of the “contest”. However, one thing is clear. And the clear fact is following one: the evidence convincingly shows that the dynamics of the Greenland’s ice is qualitatively similar to what it was 80 years ago when the carbon dioxide emissions per year were 4 times lower than today. That is, carbon dioxide has NOT been a factor in the recent retreat. Now for ARC vs Rignot. Not sure where you got your ARC quote from because neither ARC 2010 nor 2011 cite Rignot. Are you confusing… Read more »

Richard C (NZ)
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Richard C (NZ)

The relevant ARC SMB plot is here:-

http://www.arctic.noaa.gov/report10/figures/GL5.png

[Some things get mistakenly omitted after 10hr night shifts]

I note this from the Rignot conclusion:-

“Most likely, the ice sheet mass deficit in the 1925–1935 warm period was larger than in 1958”

That pesky 30s warm period again. Still around despite Hansen’s best efforts to adjust it away.

Richard C (NZ)
Guest
Richard C (NZ)

A conundrum especially for you Nick:-

Ice Age At 2000+ PPM CO2

Climate during the Carboniferous Period [linked]

Earth experienced an ice age 450 million years ago, with CO2 somewhere between 2000 and 8000 ppm. According to Hansen’s theories – all life on Earth should have been extinct before it even evolved.

http://stevengoddard.wordpress.com/2012/05/31/ice-age-at-2000-ppm-co2/

How does that CO2 “forcing” work again?

Nick
Guest
Nick

1 – Knud Rasmussen’s pictures. You originally claimed that the article showed Greenland was melting more quickly 80 years ago than it is today. From the quote above it is clear that the author makes no such claim, at best he shows that the rate may have been about the same. I don’t know why you are dragging CO2 into it I have never made any claim regarding correlation between CO2 and melting. I’m just pointing out that contrary to what many here seem to believe the ice sheets are melting and at an accelerating rate as shown by many independent lines of inquiry. Since we both appear to agree that melting is occurring perhaps we can look at how this compares with past events rather than rushing into attribution to CO2 or otherwise, I suspect we will find little common ground there and I would prefer to discuss things where there is some hope of agreement (however faint 🙂 ). It is also worth noting that the actual pattern of glacier retreat is much different today than it was 80 years ago. In the 30’s it was land terminating glaciers retreating. Today… Read more »

Richard C (NZ)
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Richard C (NZ)

“I don’t know why you are dragging CO2 into it” That is why we are here Nick. If CO2 is not the controlling factor (no correlation) then man-made climate change wrt Greenland ice loss is not an issue. “ARC does not contradict Rignot” What I am getting at Nick is that you have portrayed Greenland ice SMB as a loss-only situation (citing Rignot) when clearly that is NOT the case (75% of ARC values are ABOVE the 0 anomaly line last 30 yrs 1967 – 1997). This at a time when anthrro CO2 is said to be influential (the undisputed predominant climate driver and planetary control knob),The influence is apparently SMB greater than normal for 3/4 of the standard climate period. “I think it is generally accepted that the Holocene climatic optimum was due to Milankovitch cycles” Thank you finally for acknowledging cyclicity, “Perhaps you could tell me the period and amplitude of the cycle you are claiming exists before I decide if it is apparent or not” If you can tell me the period and amplitude of the interdecadal oscillations in GAT and SST (I would be interested too, to know if… Read more »

Richard C (NZ)
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Richard C (NZ)

Re your conundrum Nick.

The climate models use a forcing parameter based on the equation ÄF = 5.35 ln C/Co

Further documentation in the IPCC reports states that the forcing of each watt/m2 raises the global temperature by 0.75°C.

Therefore, for the situation 450 million years ago when CO2 levels rose 500 ppm here:-

http://stevengoddard.files.wordpress.com/2012/05/image277.gif?w=640&h=404

We can use the values Co = 4000 and C = 4500.

ÄF = 5.35 ln 4500/4000

ÄF = 5.35 ln 1.125

ÄF = 0.63 W/m2

Global temperature rise (supposedly) = 0.63 x 0.75 = 0.47°C

But in reality (something we’re particularly focussed on here Nick), Global temperatures plunged 15°C.

And just as it was 450m yrs ago, the CO2 rise this century has not resulted in global temperature rise. It would seem then, that the IPCC’s RF methodology is one of the more bone-headed constructs in respect to AGW because it neglects the overwhelming influence of natural variations. Wouldn’t you agree Nick?

[Someone check the calcs (Bob?). I have a brain full of kiwifruit dust, sleep deprivation and ears ringing from the incessant clatter of packing operations (labellers 80db). Not always conducive to clear reasoning I’ve found]

Mike Jowsey
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Mike Jowsey

It’s not an overdose of Keystrepto is it Richard?

Nick
Guest
Nick

Hi Richard, There may well have been a small net gain of ice between 1970 and the 1990s. Certainly the Rignot paper does not preclude it. You do need to keep in mind that increasing temperatures increase precipitation (ie it snows more) as well as increasing run off. It is quite possible that ice mass increases in the short term until increasing ocean temperatures and run off become the dominant factor. It is also worth noting that the current rate of ice loss is about 6 times greater than the rate of ice gain in 1970-2000 and while the mass gain of approx 50Gt/yr was fairly constant the current mass loss of greater than 300Gt/yr is accelerating. Regarding the Grand solar minimum Feulner and Rahmstorf. 2010. On the effect of a new grand minimum of solar activity on the future climate on Earth http://www.pik-potsdam.de/~stefan/Publications/Journals/feulner_rahmstorf_2010.pdf Find that “a moderate temperature offset of no more than −0.3°C in the year 2100 relative to a scenario with solar activity similar to recent decades. This temperature decrease is much smaller than the warming expected from anthropogenic greenhouse gas emissions by the end of the century” The existence… Read more »

Richard C (NZ)
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Richard C (NZ)

Still searching for that CO2 correlation Nick? Greenland ice loss (or gain) is of no consequence to man-made climate change alarm if you can’t.

Re F&R2010

“a moderate temperature offset of no more than −0.3°C in the year 2100 relative to a scenario with solar activity similar to recent decades”

Forget the “scenario with solar activity similar to recent decades”. The actual scenario has yet to play out and possibilities range from continued stasis (no warming or cooling but with sporadic cool episodes to conditions similar to LIA.

“This temperature decrease is much smaller than the warming expected from anthropogenic greenhouse gas emissions by the end of the century”

Is the warming expected from anthropogenic greenhouse gas emissions by the end of the century similar to what we’ve experienced at the start?

You say:-

“….the anthropomorphic influence is steadily increasing”

In the disconnected world of climate change alarmism it is but in the real world it has been conspicuous by it’s absence.for some time now.

Richard C (NZ)
Guest
Richard C (NZ)

Re Rignot:-

“The new Bjørk et al. (2012) study (as well as a slew of other recent studies which we have discussed: see here, here, here, here, here , and here for example) strongly suggests that “present trends” will not continue—and thus the Rignot et al. extrapolation is grossly inaccurate (i.e., far too large).

http://www.worldclimatereport.com/index.php/2012/06/04/historical-imagery-of-greenland-glaciers-lessens-sea-level-rise-alarm/

Richard C (NZ)
Guest
Richard C (NZ)

Fraunfeld et al., 2011 concluded (from WCR): The forces acting in concert with ice melt across Greenland to produce higher global sea levels currently, should also have been acting during the extended high‐melt conditions from the mid‐1920s to the early 1960s. There is some qualitative indication of an observable influence of the variations in input from Greenland in the decadal rates of sea level change over the course of the past century… However, there is no indication that the increased contribution from the Greenland melt in the early to mid 20th century, a roughly 40 year interval when average annual melt was more or less equivalent to the average of the most recent 10 years (2000–2009), resulted in a rate of total global sea level rise that exceeded ∼3 mm/yr. This suggests that Greenland’s contribution to global sea level rise, even during multidecadal conditions as warm as during the past several years, is relatively modest. http://www.worldclimatereport.com/index.php/2012/06/04/historical-imagery-of-greenland-glaciers-lessens-sea-level-rise-alarm/ All very underwhelming. WRC goes on:- Currently, ice loss from Greenland contributes about one-to-two hundredths of an inch per year to the global average sea level—that’s a total of 1-2 inches by the year 2100. So, even… Read more »

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