Dear Jennifer,
Professor Ollier takes on James Hansen’s claim that the Greenland and Antarctic ice sheets are in danger of collapse due to global warming. Hansen’s claims are the basis for Al Gore’s suggestion, in An Inconventient Truth, that the seas may rise by 20 feet in the near future.
Professor Ollier argues that, “Hansen’s seeming ignorance of the mechanism by which glaciers flow leads him into major errors.”
You may have seen Professor Cliff Ollier’s write up of glacier dynamics originally circulated by Benny Peiser’s excellent CCNet newsletter. The Center for Science & Public Policy has published a paper adapted from the original article with expanatory footnotes and diagram added to clarify some of the more technical parts of the article.
This paper describes glacier dynamics, such as the glacier budget, how glaciers flow (through a process known as “creep”), how creep is related to temperature and stress, and how the simple rules of creep allow us to understnad some observations of glaciers.
We hope you find this paper useful.
http://ff.org/index.php?option=com_content&task=view&id=396&Itemid=77
Paul Georgia
Center for Science & Public Policy
Frontiers of Freedom
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Benny Peiser and the Frontiers of Freedom. Wow !
I simply believe them. These guys are good ! Especially the tobacco work.
Hey didn’t we already club each to death on this Greenland Ollier issue recently. Oh well – let’s start up again.
One slight issue though “seas may rise by 20 feet in the near future” – umm errr where did that get said again? I just can’t remember.
re: ‘One slight issue though “seas may rise by 20 feet in the near future” – umm errr where did that get said again? I just can’t remember.’
Yet another predictable tantrum and stunning display of intellect. Couldn’t figure out what the VP Gore’s AIT narrative and the flooding cartoon meant, eh, Lil’ Lukefish? Must be a tough for you — simple german GKSS climatologist translation involving “rubbish” auf Deutsch, and now an AIT CARTOON stumps you? Surprise and shock to us all…
We’ll leave out your complete misunderstanding of “the divergence problem” with AR4 … wait — maybe you want to come back and play at Warwick’s house?
Well all very bellicose and fascinating – but where was that reference again…?
I know denialists like Mccall don’t like it when called to task… – let’s be specific.
“Professor Ollier takes on James Hansen’s claim that the Greenland and Antarctic ice sheets are in danger of collapse due to global warming”
“Hansen’s claims are the basis for Al Gore’s suggestion, in An Inconventient Truth, that the seas may rise by 20 feet in the NEAR future.”
Luke
Obviously you don’t read much – Professor Ollier restricted his analysis to Greenland – so his citation of Hansen’s interpretation of increased CO2 into the atmosphere will cause the Greenland Ice cap to melt, is accurate.
Equally Al Gore needs a catstrophic source of water to cause sea levels to rise 20 feet or so, in the same period. Greenland’s assumed melting fulfils that requirement.
Hence your last comment is somewhat correct though why you need to include Antarctica into the scenario remains only something you know about.
Maddening isn’t it, being the only one here who “knows”.
Louis,
You’re such an Uber-noob (1) I am re-quoting the lead post which says Antarctica – (“cripes didn’t think of that” says Louis and disappears in a puff of logic). LMAO to the nth power.
Paul has already posted a comprehensive summary of this paper here: http://www.jennifermarohasy.com/blog/archives/002510.html .
And Luke Walker has nothing new to add, it seems?
(Sorry for the double posting)
Everytime I see something like this I wonder when and who is going to get this message out. I mean out so that every Joe Blow on the street can say “Sorry Mr. Gore but the ice cap of greenland is sitting in a bowl and it is impossible for it to flow into the ocean.” or “Sorry Mr. Gore but icecaps melt from the bottom due to heat from the Earth’s core, not from surface air temperature.
I want that guy hounded. I want him mainlining Milk of Magnesia for his chronic worry ulser.
I want him to be embarrassed to show his face in public. I want him to retreat from the laughter when ever he pokes his head out of his limo or greenhouse gas belching private jet. I want the school children to pelt the screen with spitwads whenever they show AIT in a classroom.
That’s not too much to ask for, is it?
James – “Sorry Mr. Gore but the ice cap of greenland is sitting in a bowl and it is impossible for it to flow into the ocean”
Whaaaat! – what about the times in the past when it has been ice free???? Impossible for it to melt????
“Sorry Mr. Gore but icecaps melt from the bottom due to heat from the Earth’s core, not from surface air temperature.”
Really do they??? Where do you get your info from perhaps you could supply a reference for this piece of crap.
hmmmm seems like LSD flashbacks still. happen “Peace out man” indeed.
Gee I wonder how any melting in the past occurred.
Funny thing earthquakes – I think we’re building up to another one.
Now James – let’s just play some charades until the helpful men arrive again. Quietly now. I know – let me guess – you’re imitating a goose.
lets see. The last time greenland would have been ice free hmm… the Cretaceous period? But then Greenland would have just been a blob of land sticking out the north side of Pangaea. Don’t think that counts.
Try again dude.
Jennifer,
it’s like asking Luke why he constantly says gravity makes things fall down. It’s always the same story, nothing new there either.
James you helping my earthquake theory no end:
(1) we’re not talking about ice free
(2) not talking that far back.
Try to do some research and keep off the streets eh.
James – “The last time greenland would have been ice free hmm… the Cretaceous period? But then Greenland would have just been a blob of land sticking out the north side of Pangaea. Don’t think that counts.”
Well it does actually as you said that it would be impossible for the Greenland ice to melt and yet is has melted to some extent in the interglacial and Greenland has been ice free. Perhaps you should be more careful with the word impossible. The current thinking is:
“Projecting forward in time, the implication is that our future will also see 4-6 m of sea level rise, and that — given the recent evidence for accelerated flow of both Greenland and Antarctic glaciers — this may occur much faster than we expect. In the model simulations, Greenland may already be warmer in 2100 than it was at the height of the LIG. The rate of sea level rise associated with the warming into the last interglacial was probably greater than 10 mm/yr* while current sea level rise is roughly 3 mm/yr. To the extent that the LIG is a good analog for our future, sea level rise is therefore rather likely to accelerate.”
4 to 6 meters is a hell of a lot of water and will inundate coastal areas. The whole Greenland ice sheet does not have to melt to cause problems.
James – BTW perhaps you should do some more research:
http://en.wikipedia.org/wiki/Greenland_ice_sheet
“The ice in the current ice sheet is as old as 110,000 years[3] However, it is generally thought that the Greenland Ice Sheet formed in the late Pliocene or early Pleistocene by coalescence of ice caps and glaciers. It did not develop at all until the late Pliocene, but apparently developed very rapidly with the first continental glaciation.”
and
http://en.wikipedia.org/wiki/Pleistocene
“The modern continents were essentially at their present positions during the Pleistocene, the plates upon which they sit probably having moved no more than 100 km relative to each other since the beginning of the period.”
Ender – indeed and aren’t facts tedious for our denialists who continue to exaggerate and deliberately misrepresent what has been written. How many times have we been over this now.
It seems our denialists are now alarmist denialists.
Melting of all terrestrial ice systems (Jame’s try-on) would add some SIXTY-NINE METRES of sea level – have you seen that mentioned anywhere?
Mr Ender and Lil’ Lukefish agreeing on, “given the RECENT evidence for accelerated flow of both Greenland and Antarctic glaciers” crap? Try again!
Try “Recent Ice-Sheet Growth in the Interior of Greenland” – Johannesen’05. — the Greenland Ice Sheets NET GROWTH was 21+ inches over 1993 to 2003. The interior high altitude ice sheet area was adding much faster than fringe low-level was melting. And this even happened during the HS (or more appropriately, the BS AR4) warmest decade in 1300 years.
As for the shrinking Antarctic Ice Sheet, you must be using that Gore-spew of Velicogna’06? It did show shrink that was due to the smaller West Antarctic Ice Sheet mass over a brief study period of a whopping 3+ years. Climatically, this is a joke that will likely be punch-lined when the analysis of the ‘07 winter comes in — you know, the one with record ice area as of 26-SEP-07 (The Cryosphere Today)?
And it is a cherry-pick! Davis ‘05 showed net Antarctic growth over a longer period from 1993-2003 — the end year overlaps the start of Velicogna’s 3+ years of brief decline. Then there’s Chen’06; Ramillien’06; and van de Berg’06 all showing growth in the massive and dominating East Antarctic Ice Shelf — which carries over to net increase of all of Antarctica.
Lil’ Lukefish — you should have warned Mr Ender that you already got filleted on this elsewhere. Wanna switch to the divergence problem?
Well Quickdraw I think you should carefully read what I’ve said on the issue. First base is to to get through the massive misrepresentation of what Hansen has actually said.
I enjoy your classicly assumptive style “you must be using ” is that so?
As for increased deposition in these areas – yep as you would expect. I would have thought a smarty pants like youself would’ve preferred not to mention such.
🙂 Think about it.
P.S. As for the divergence problem don’t beat around the bush – give us a guest post Quickdraw.
Ender,
accelerated flow from the glaciers means but one simple fact – that in the headwaters of these glaciers there is an enormous precipitation of snow, hence ice, which by gravity, pushes the ice down the valleys so that the glaciers disgorge this ice into the oceans. It is called “glacial calving” and is evidence of ice production, not ice reduction.
If melting were indeed the case, then glacial calving would be noted for its absence, and glaciers noted for their retreat backwards into the valleys constraining their flow.
Neither you or Luke have no idea about this topic. You are both blathering idiots.
a Non sequitur was added above, but for whom will the recognition inspire?
Careful Louis I’m an expert in earthquake origins.
Luke, are you fishing?: “Funny thing earthquakes – I think we’re building up to another one.” “I’m an expert in earthquake origins”…
I’ve also been boning up on earthquakes over the last month or so and what I’m seeing over the last couple of years around the western rim of the “Ring of Fire” is a hockey stick… I haven’t decided if it’s an artifact of improved measurements or whether it’s real, but there is a significant increase in earthquakes. And not just tremors – mag 6 and up happening constantly. May be worth a thread in its own right?
But since we’re on Greenland, there are a couple of things I’d like to point out.
There is ample evidence that during the Medieval Warm Period, the southern and north western Greenland environment was conducive to “European” type habitation for hundreds of years:
http://www.archaeology.org/online/features/greenland/
http://www2.sunysuffolk.edu/mandias/lia/end_of_vikings_greenland.html
This implies that the temperatures were as warm if not warmer than today – i.e. because we still can’t do it now. (Which is why I think that basing a paleoclimate record on a couple of strip barked pine trees that runs contrary to this is a bit suspect).
And the Greenland icecap and glaciers did not melt.
During the last interglacial, some 116,000-130,000 years ago the temperatures were some 5C higher than now:
http://www.nature.com/nature/journal/v431/n7005/full/nature02805.html;jsessionid=FC1A0B4DFEF8B016D8D3A5317CAD5685
And the Greenland icecap and glaciers did not melt.
Over the last million years, the southern edge of Greenland supported flora that is now found in the northern boreal forests, plus beetles, spiders etc etc that is just not found there today – i.e. the temperatures were FAR higher than today:
http://www.sciencemag.org/cgi/content/full/317/5834/111?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=greenland+ice+core&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT
And the Greenland icecap and glaciers did not melt.
Do you know why I know they did not melt? … Drum roll… Because somebody drilled them to find all this out!
Hansen’s got it wrong, and Ollier (very probably) has it right.
cheers
Arnost
Louis – “If melting were indeed the case, then glacial calving would be noted for its absence, and glaciers noted for their retreat backwards into the valleys constraining their flow.”
http://www.livescience.com/environment/051116_greenland_melts.html
“A new study reveals one of the largest glaciers in Greenland is shrinking and speeding to the sea faster than scientists expected. If it continues, Greenland itself could become much smaller during this century and global seas could rise as much as 3 feet.
“The rates of change that we’re observing are much higher than expected,” said Ian M. Howat of the University of California, Santa Cruz. “If these rates of response continue, it is not unlikely that Greenland could shrink by several tens of percent this century.””
http://www.solarviews.com/eng/earthpr1.htm
“In the March 5 issue of SCIENCE, researchers report the glacial thinning is too large to have resulted from increased ice- surface melting or decreased snowfall. The researchers believe the thinning, as much as 30 feet over five years in some locations, is the result of increasing discharge speeds of glaciers flowing into the Atlantic Ocean.
Krabill said surface-melt water might be seeping to the bottom of glaciers. Such seepage may be reducing the friction between the ice and the rock below it, enabling the glaciers to slide with less friction across the bedrock and thus allow more ice to slip off into the ocean, according to Krabill. ”
http://researchnews.osu.edu/archive/greenice.htm
“The finding has surprised scientists, because while the margins of the Jakobshavn (pronounced “yah-cub-SAH-ven”) Glacier had been slowly retreating from the southwest coast of Greenland since before 1900, this retreat appeared to have stopped by the early 1990s when the first accurate measurements were made. Now the glacier is accelerating.
Bea Csatho
The glacier, one of the major drainage outlets of Greenland’s interior ice sheet, is thinning more than four times faster than it had for most of the 20th Century. Accompanying this thinning is a substantial increase in ice speed. ”
It is a bit like shooting ducks in a barrel.
Mccall – “Try “Recent Ice-Sheet Growth in the Interior of Greenland” – Johannesen’05. — the Greenland Ice Sheets NET GROWTH was 21+ inches over 1993 to 2003. The interior high altitude ice sheet area was adding much faster than fringe low-level was melting. And this even happened during the HS (or more appropriately, the BS AR4) warmest decade in 1300 years.”
Try this instead:
http://www.sciencedaily.com/releases/2007/03/070327122328.htm
“Grace measurements have revealed that in just four years, from 2002 to 2006, Greenland lost between 150 and 250 cubic kilometers (36 to 60 cubic miles) of ice per year. One cubic kilometer is equal to about 264 billion gallons of water. That’s enough melting ice to account for an increase in global sea level of as much as 0.5 millimeters (0.019 inches) per year, according to Isabella Velicogna and John Wahr of the University of Colorado, Boulder. They published their results in the scientific journal Nature last fall. Since global sea level has risen an average of three millimeters (0.1 inch) per year since 1993, Greenland’s rapidly increasing contribution can’t be overlooked.”
The gains in the centre are being outweighed by losses at the margins.
Ender, do us all a favour and go and read Ollier, properly, without the paper bag over your head. All the references you provided were based on the same mix of ignorance and moronic speculation as Hansen’s.
You and Luke have been doing your classic set of diversionary vaudeville in a pathetic attempt to induce some (any) sad plodder to ignore Ollier’s work.
The facts on Greenland remain the same. On the available evidence, and ignoring new ice formation as per Johanessen, the 2.5 million km3 of ice will take 19,000 years to melt. Any so-called science that is based on an increase in the melt rate is nothing but speculation.
And if the total ice volume in Greenland would raise sea level by 7 metres then it follows that, at most, we can be “confronted” (add emotive term of choice) by no more than 37mm of Greenland sourced sea level rise over the next century.
Ollier has made it very clear that Hansen is a climate bimbo.
And has Mott read Hansen – of course not. Waste of time talking to these guys Ender.
Ender I am really dissappointed with your first Wiki link. I thought you were going to show me something that proved me wrong – blow my hair back.
Instead I find: – The massive weight of the ice has depressed the central area of Greenland; the bedrock surface is near sea level over most of the interior of Greenland, but mountains occur around the periphery, confining the sheet along its margins –
which is astonishingly simular to “Sorry Mr. Gore but the ice cap of greenland is sitting in a bowl and it is impossible for it to flow into the ocean.”
Or if you would prefer “Sorry Ender but the ice cap of greenland is sitting in a bowl and it is impossible for it to flow into the ocean.”
Also there is a link to the North Greenland Ice Core project – http://www.glaciology.gfy.ku.dk/ngrip/presse_070804_eng.html – where I found confirmation that our boy, Professor Cliff, knows what he is talking about. Geothermal heating from the bottom up, red basil melt water part of a sub-glacial water system that has been isolated from
the surface for perhaps several million years.
Next.
Atmos. Chem. Phys., 7, 2287–2312, 2007
However, Earth’s history shows that the long-term response
to global warming includes substantial melting of ice and sea level rise. During the penultimate interglacial
period, 130 000 years ago, when global temperature may
have been as much as 1C warmer than in the present interglacial
period, sea level was 4±2m higher than today (Mc-
Culloch and Esat, 2000; Thompson and Goldstein, 2005),
demonstrating that today’s sea level is not particularly favored.
However, changes of sea level and global temperature
among recent interglacial periods are not large compared to
the uncertainties, and ice sheet stability is affected not only
by global temperature but also by the geographical and season
distribution of solar irradiance, which differ from one interglacial
period to another. Therefore, it is difficult to use the
last interglacial period as a measure of the sensitivity of sea
level to global temperature. The most recent time with global
temperature 3C greater than today (during the Pliocene,
3 million years ago) had sea level 25±10m higher than today
(Barrett et al., 1992; Dowsett et al. 1994; Dwyer et al.,
1995), suggesting that, given enough time, a BAU level of
global warming could yield huge sea level change. A principal
issue is thus the response time of ice sheets to global
warming.
It is commonly assumed, perhaps because of the time scale
of the ice ages, that the response time of ice sheets is millennia.
Indeed, ice sheet models designed to interpret slow paleoclimate
changes respond lethargically, i.e. on millennial
time scales. However, perceived paleoclimate change may
reflect more the time scale for changes of forcing, rather than
an inherent ice sheet response time. Ice sheet models used
for paleoclimate studies generally do not incorporate all the
physics that may be critical for the wet process of ice sheet
disintegration, e.g. modeling of the ice streams that channel
flow of continental ice to the ocean, including effects of
melt percolation through crevasses and moulins, removal of
ice shelves by the warming ocean, and dynamical propagation
inland of the thinning and retreat of coastal ice. Hansen
(2005a,b) argues that, for a forcing as large as that in BAU
climate forcing scenarios, a large ice sheet response would
likely occur within centuries, and ice melt this century could
yield sea level rise of 1m or more and a dynamically changing
ice sheet that is out of our control.
Two regional climate changes particularly relevant to ice
sheet response time are: (1) surface melt on the ice sheets,
and (2) melt of submarine ice shelves that buttress glaciers
draining the ice sheets. Zwally et al. (2002) showed that
increased surface melt on Greenland penetrated ice sheet
crevasses and reached the ice sheet base, where it lubricated
the ice-bedrock interface and accelerated ice discharge
to the ocean. Van den Broeke (2005) found that unusually
large surface melt on an Antarctic ice shelf preceded
and probably contributed significantly to collapse of the ice
shelf. Thinning and retreat of ice shelves due to warming
ocean water works in concert with surface melt. Hughes
(1972, 1981) and Mercer (1978) suggested that floating and
grounded ice shelves extending into the ocean serve to buttress
outlet glaciers, and thus a warming ocean that melts ice shelves could lead to rapid ice sheet shrinkage or collapse.
Confirmation of the effectiveness of these processes
has been obtained in the past decade from observations of
increased surface melt, ice shelf thinning and retreat, and acceleration
of glaciers on the Antarctic Peninsula (De Angelis
and Skvarca, 2003; Rignot et al., 2004; van den Broeke,
2005), West Antarctica (Rignot, 1998; Shepherd et al., 2002,
2004; Thomas et al., 2004), and Greenland (Abdalati et al.,
2001; Zwally et al., 2002; Thomas et al., 2003), in some
cases with documented effects extending far inland. Thus
we examine here both projected surface warming on the ice
sheets and warming of nearby ocean waters.
Summer surface air temperature change on Greenland in
the 21st century is only 0.5–1C with alternative scenario climate
forcings (Fig. 4), but it is 2–4C for the IPCC BAU scenarios
(A2 and A1B). Simulated 21st century summer warmings
in West Antarctica (Fig. 4) differ by a similar factor, being
0.5C in the alternative scenario and 2C in the BAU
scenarios.
Submarine ice shelves around Antarctica and Greenland
extend to ocean depths of 1 km and deeper (Rignot and Jacobs,
2002). Figure 7b shows simulated zonal mean ocean
temperature change versus depth for the past century and the
21st century. Despite near absence of surface warming in the
Antarctic Circumpolar Current, warming of a few tenths of
a degree is found at depths from a few hundred to 1500 m,
consistent with observations in the past half-century (Gille,
2002; Aoki et al., 2003). Modeled warming is due to GHGs,
with less warming when all forcings are included.
Maps of simulated temperature change for the top 1360m
of the ocean (Fig. 7a) show warming around the entire circumference
of Greenland, despite cooling in the North Atlantic.
This warming at ocean depth differs by about a factor
of two between the alternative and BAU scenarios, less
than the factor 4 difference in summer surface warming
over Greenland and Antarctica, consistent with the longer response
time of the ocean. Although we cannot easily convert
temperature increase into rate of melting and sea level rise, it
is apparent that the BAU scenarios pose much greater risk of
large sea level rise than the alternative scenario, as discussed
in Sect. 6.
Recent Sea-Level Contributions of the Antarctic and Greenland Ice Sheets
Science 315, 1529 (2007);
Andrew Shepherd, et al.
Recent Sea-Level Contributions of the
Antarctic and Greenland Ice Sheets
Andrew Shepherd1 and Duncan Wingham2*
After a century of polar exploration, the past decade of satellite measurements has painted an
altogether new picture of how Earth’s ice sheets are changing. As global temperatures have risen,
so have rates of snowfall, ice melting, and glacier flow. Although the balance between these
opposing processes has varied considerably on a regional scale, data show that Antarctica and
Greenland are each losing mass overall. Our best estimate of their combined imbalance is about
125 gigatons per year of ice, enough to raise sea level by 0.35 millimeters per year. This is only a
modest contribution to the present rate of sea-level rise of 3.0 millimeters per year. However, much
of the loss from Antarctica and Greenland is the result of the flow of ice to the ocean from ice
streams and glaciers, which has accelerated over the past decade. In both continents, there are
suspected triggers for the accelerated ice discharge—surface and ocean warming, respectively—
and, over the course of the 21st century, these processes could rapidly counteract the snowfall
gains predicted by present coupled climate models.
James – “I am really dissappointed with your first Wiki link. I thought you were going to show me something that proved me wrong – blow my hair back.
Instead I find: – The massive weight of the ice has depressed the central area of Greenland; the bedrock surface is near sea level over most of the interior of Greenland, but mountains occur around the periphery, confining the sheet along its margins –
which is astonishingly simular to “Sorry Mr. Gore but the ice cap of greenland is sitting in a bowl and it is impossible for it to flow into the ocean.”
Or if you would prefer “Sorry Ender but the ice cap of greenland is sitting in a bowl and it is impossible for it to flow into the ocean.””
And that would be yes it is impossible for it to flow into the ocean except where it is. Please read links after this where studies show that the rate of melting and flowing into the ocean is increasing.
Also in the last interglacial:
“First, in a paper by Otto-Bliesner et al. they ran simulations for the Last Interglacial, and took a look at what happened to the ice sheets. They find that most of the icefields in Arctic Canada and Iceland disappear, and that the Greenland ice sheet is reduced to a steep ice dome in central and northern Greenland. These results are in very good agreement with the available ice core and other paleoclimate data evidence, which indeed show that the Canadian ice sheets disappeared during the LIG, and strongly suggest that much of southern Greenland was deglaciated.”
So obviously it is actually impossible for the Greenland ice to melt except when it does.
Not sure where this leaves you.
From your link:
“The Greenland ice sheet ice is melting from the bottom of the ice sheet AT THIS SITE due to high
geothermal heat” (my capitalisation)
This site has significant geothermal heating and no reference is made to overall heating.
All of a sudden, models are quite believable, James?
Standard side step by Luke. Of course I have read Hansen, hard to avoid really. But if cornered, Luke will look for ANY excuse to duck for cover.
Lets get this clear, THERE IS ONLY ONE TIPPING POINT. That is the temperature at which ice melts, ie 0.0C. The greenland ice sheet in mid summer is still between -20C and -30C and to suggest that this might all just slip away after an increase in global tyemperature of 2 or 3C is plain silly.
No, Ian. Ice sheet’s collapse, for a start. They become destabilised when one part melts, and the parts that didn’t melt depend on the parts that did. Also, no-one said it’s all going to go.
Ender – increasing from zero, yes I saw that link. You didn’t get the language exactly right. I believe the term used was accelerating. How isn’t “accelerate” much more alarming term then “increasing”? You have to pay attention to these nuances if you want to be a big league fear monger.
I’m looking at this map from 1440 made by some Viking dude – it shows Greenland as an island.
http://www.econ.ohio-state.edu/jhm/arch/vinland/vinland.htm
I’m thinking, how did a Viking sail all the way around Greenland some time prior to 1440, when today it’s so much hotter then back in that medieval time? Even with the Arctic ice retreated to it’s smallest size in “history”, Greenland today is still locked by unnavigable pack ice all year round.
http://www.realclimate.org/index.php/archives/2007/08/arctic-sea-ice-watch/
Could someone explain it to me?
Ian’s level of retort is now approaching the pinnacle of silliness. Indeed approaching Kafkaesque.
(1) We’re stuck on 100% MELT – that’s ALL folks of Greenland melting. How friggin stupid is this.
(2) Although it can’t melt we’re posting papers how forests have been in Greenland before – but this can’t be coz it can’t melt.
(3) interesting that Mottsa has now read a paper we’ve never metioned before. Thought he might of mentioned it. Yea sure. Bulldust.
(4) Antarctica’s involvement keeps slipping away as a discussion point yet the main source
(5) Despite all the nonsense the latest 2007 review puts the net mass balance as negative. (Notwithstanding – obvious caveats about decadal trends and a record 2007 southern season)
(6) We seem to have moved from there cannot be any liquid water – to oceans of it – natural dykes that occasionally break causing floods
(7) Surprise surprise – the models seem to predict increased snowpack which is what sprucing up the hydrological cycle would effect.
(8) the fact that sea level has varied considerbaly in the past seems TOTALLY ignored
(9) ice pack edges don’t nicely melt – they DISINTEGRATE and SLIDE
(10) flow is obstructed by buttresses which hold back the flow. Dislodge the buttresses and the flow will increase.
Is Hansen right – dunno – still a number of unknowns – but his clear and well referenced argument is heaps better than the sheer stupidity displayed in the puerile denialist arguments here.
As for Ollier – well none of Hansen’s hypothesis is necessarily inconsistent with his observations.
You dont like Kafka fly-boy?
thismustbebecauseyouwokeupthismorningasagiantinsect.
Fly papaer can be lethal to bugs.
James – “I’m looking at this map from 1440 made by some Viking dude – it shows Greenland as an island.”
Would this Viking dude be the same guy down the pub that John McLean got the info about the MWP having to be disappeared?
Maybe he just made the map up to try to sell Greenland real estate – you know what these people are like.
Luke, with your last sentence you have proven beyond doubt that you don’t have a clue.
None of Hansen’s hypothesis? is inconsistent with his observations? Hypotheses are usually based on observations, so it would be somewhat unusual for Hansen’s hypothesis to be inconsistent with his observations.
And think carefully about replying Luke.
rog,
I think the above is the first post from Luke in quite a while where I am encouraged to enter the fray and have a chat (and not be afraid of having my head chewed of…). Don’t, just DON’T irritate the curmudgeon. 🙂
James
have you seen the 1440 map of Australia?
OK, here’s an attempt at a start of rational discourse. Let’s start with the “Lets get rid of the MWP” piece.
Here’s a good bibliography to start with. http://ncpa.org/pub/st/st279/st279m.html
The second citation on this list is to Tkachuk, (here in full: http://www.grisda.org/origins/10051.htm ) where reconstruction fig 1f (using the same Bristlecone Pine Trees that are the MBH PC1) shows that the MWP was a bit warmer than 1970’s (from LaMarche 1974 Science 183:1043-1048). Futher, the fig 1a reconstruction in Tkachuk from Lamb 1997 shows a markedly higher MWP than the 1970’s.
An interesting read and the list goes on…
I don’t think that any one in all seriousness now will claim that the MBH reconstruction is not suspect (and this therefore has to extend to all the rest that depend on the MBH PC1, i.e. Hergel, Juckes, Osborn, and as it now turns out even Al Gore’s “Dr Thompson’s thermometer” that was shown as supposedly an independent support for the MBH hockey stick).
It’s interesting to note that the Moberg 2005 reconstruction has a pronounced MWP, which, with the elimination of the Arabian Sea G.Buloides proxy – which is openly acknowledged as being not a temperature proxy but a trade wind proxy (ref David Black’s criticism of the Baliunas & Soon 2003 paper) – would be considerably higher.
And then there are the Briffa Yamal substitutions for the Polar Urals proxy without which the MWP would also be much higher.
I have lots more ammunition. Icecore and borehole temp reconstructions all support the existence of the MWP on a global scale.
This would lead me to conclude that there has indeed been a concerted effort to “get rid of the MWP”. It appears that a rather large and independent body of work is now largely ignored and dismissed in favour of the single MBH piece of work, and most of the more recent reconstructions are slanted such that the MWP is eliminated or at least minimised. So whether you heard that in a pub or not – the evidence shows that this indeed is what has occurred and that history has been re-written for political and (esp. in the case of Al Gore) economic gain.
cheers
Arnost
Arnost can I encourage you to do a guest post on the issue. Plus tell us what’s left after you exclude everything that asserted to be sus.
I also note D’Arrigo has also reviewed the divergence issue.
So if you’ve got some ammo – give us both barrels.
Luke, if I had the time to do something like that properly, I would get it published in E&E rather than here 🙂 …
It is tempting though… However, if I did a summary of the strengths and weaknesses of the climate papers now and past, and had it as a lead post then (having an ego bigger than the planet) it would be painfull to defend it against the concerted ad homs and irrelevant diversions that currenly seem to be par for the course in this forum. And I really do not have the time to do this.
Seriously though, the fact remains that since MBH98 the majority of the mainstream paleoclimate reconstructions all seem to follow the same agenda. “Get rid of the MWP”. Steve McIntyre has done a sterling job of nit picking this work and is showing it (not all – but a lot) as pretty “lousy” (pun intended). All I would be doing would be leveraging his work plus bringing in some of the older reconstructions – which after all were what the famous AR1 “cartoon” was based on. It’s all out there for anyone interested – and really, not that difficult to find.
By the way, if I was in Steve’s shoes I would not publish any papers in the journals. I would publish a book (maybe multi-volume) assessing the science much in the same way you suggest I do. Get a couple of avaricious post-docs to do the menial stuff and detailed research, a good ghost writer with a sense of humour to match his… It would make squillions. Guranteed that you’d buy it.
So – as an aside – were you really fishing with the earthquake stuff? That’s something that I may be tempted to do. Joint guest post?
Oh, by the way – in science everything is “sus” so my net contribution will be what follows:
… Sounds of crickets chirping …
Arnost – Ok lets for the sake of argument assume that there is this conspiracy within the AGW scientific community to suppress the MWP.
What does it get you? MacIntyre’s sole job was (now I think it borders on obsession) was to inject sufficient doubt into the debate to deflect attention from the real issues. In this he succeeded brilliantly and now, apart from needing an appointment with Dr Phil, has delayed action on climate change and fulfilled the wishes of his masters.
As has been pointed out many many many many many many many many many many many many and yet again in the 100 year hockey stick wars that MBH99 was a first attempt that set the smoothing techniques high and suppressed the MWP. Later analysis’s done with the benefit of MBH99 could play around with the smoothing factors and the MWP re-appeared.
The MWP is not the killer of AGW as you seem to think. That is not to say that it is not interesting however it is a side issue and nothing more than that. The ‘suppression’ of the MWP is also nothing more than data smoothing.
I really do no know where you are going with this and McIntyre really needs a basket weaving course or something.
of all the places for those Danes to drill, they just happen to pick a spot in the middle of Greenland that supports Ollier – That is amazing luck.
From Sheperd, above,
“Our best estimate of their combined (Greenland AND Antarctica) imbalance is about 125 gigatons per year of ice, enough to raise sea level by 0.35 millimeters per year.” (or a mere 35mm/ century)
“This is only a modest contribution to the present (dubious) rate of sea-level rise of 3.0 millimeters per year. However, much of the loss from Antarctica and Greenland is the result of the flow of ice to the ocean from ice streams and glaciers, which has accelerated over the past decade. In both continents, there are
suspected (ie speculative, unproven, indeed, imaginary) triggers for the accelerated ice discharge—surface and ocean warming, respectively— and, over the course of the 21st century, these processes could (ie. might, not will) rapidly counteract the snowfall gains predicted by present coupled climate models.
But such is the impaired cognitive function of Spivanthropus climatecretinensis that these highly conditional, speculative, statements are taken as fact. So lets look at these so-called drivers again, surface and ocean warming, that MIGHT counteract the snow fall gains.
Surface and ocean warming is exactly that, surface warming. The snow fall gains in Greenland are taking place at an altitude of 2000m while those in Antarctica are taking place at altitude 3000m. So they are automatically 20C and 30C colder than the surface conditions.
Yet, Hansen made it clear that he believed the entire sheet would reach his “tipping point” beyond which it would rapidly collapse. But new snowfall could only begin that process when the altitude of the sheet has undergone major (ie 75%+) decline.
That is not to say that a theoretical point of rapid decline is not possible. Rather, due to the thermal mass and altitude of the ice sheets, any decline is likely to remain very slow for many millenia before an actual rapid decline sets in.
And the less said about Luke’s 10 point litany of bunkumitosis the better.
Ender
I think you do McIntyre a disservice by suggesting that “his sole job … was to deflect attention from the real issues” – the implication being that he purposefully wanted to delay action on climate change. Nothing of the sort – he just wanted dodgy science exposed.
I on the other hand WOULD like to see a delay on climate change.
You say that the suppression of the MWP is/was a function of statistical smoothing. This suppresses reality and hides data that may be critical to fully understanding the current climate. I recommend that you think about Poincare’s maxim: “never forget that exceptions are pernicious, there are laws hidden in them.”
Modern climate science approach to temperature reconstructions appears to be to select a limited set of parameters and smooth/tweak them such that they replicate reality. And if they don’t, then smooth/tweak reality – i.e. “get rid of the MWP”.
The MWP may not be a killer of AGW, but its existence sheds doubt on the thesis that humankind is the sole reason for the current warming. The increase in warming from the beginning to mid last century also can not really be well explained by the CO2 thesis. The warming in the previous century even less so. These are the pernicious exceptions that Poincare warns about. If the MWP and 18th Century warming was caused by a natural variation – and CO2 and other anthropogenic pollution, orbital cycles (and probably solar effects) was DEFINITELY not a factor – then is it not possible that this natural factor is also (currently) playing a key role?
Let’s say we achieve all the goals of mitigation / reduction of CO2 outputs as per Kyoto etc, – and spend trillions doing it, sacrifice industries and generally impoverish the world – then what happens if the temperature merrily keeps going up? What will happen if the temperatures sink to a Dalton or even Maunder minimum? We will now no longer have the resources for adaptation. This is the real risk management question that needs to be assessed – i.e. how to manage your finite resources to best effect into the future.
Formulating inappropriate policy on the basis of dodgy research may not be our best bet, and this really could do future generations a disservice. Policy decisions impacting future generations wellbeing should be done on the basis of “incontrovertible” evidence. And this is currently lacking simply because SIGNIFICANT exceptions are not explainable.
cheers
Arnost
Arnost – “Nothing of the sort – he just wanted dodgy science exposed.”
Yeah right. You just keep on believing this.
“Modern climate science approach to temperature reconstructions appears to be to select a limited set of parameters and smooth/tweak them such that they replicate reality. And if they don’t, then smooth/tweak reality – i.e. “get rid of the MWP”.”
No it is an attempt to extract data from a very noisy data set. The first go smoothed it too much and follow up studies refined the technique. Your real complaint is that MBH didn’t get the smoothing parameters right first time. Welcome to the real world.
“The MWP may not be a killer of AGW, but its existence sheds doubt on the thesis that humankind is the sole reason for the current warming”
How? Nobody maintains that human emitted CO2 is the only method of warming. Warming happens for many reasons. Natural factors are presently playing a role however their influence is dwarfed by the much larger greenhouse forcing.
You have no evidence the the MWP was anything other than an event confined to Northern Europe. You have no evidence to claim that it was warmer than today.
There is not scientist in existence that thinks that all warming is caused by humans. This is obviously ridiculous as humans have only been around for 100 000 years or so so your statement that the existence of MWP casts doubt on the present warming being caused by human greenhouse emissions is plainly wrong. It no more casts doubt on it than the fact that the last interglacial was natural or the previous one or the rest of them were all natural. This is why I cannot understand why all the crap there is about the MWP. The existence of the MWP proves nothing other then warming can be natural as well, which everybody knew anyway.
And finally if MBH had never decided to to sort out what information they could glean from a mish mash of tree ring data and never had published MBH98 and then MBH99 then this would have made absolutely no difference to the case for AGW or the needed action to mitigate AGW.
MBH99 is not the sole piece of evidence for global warming and casting doubt on one small section does not invalidate to whole theory of AGW. This is not a court of law where you have to show reasonable doubt to get a client off. In science even the best theories are accepted with holes in them because they explain more observations better than a rival theory. Often explaining or reconciling the holes is where science really advances. However such advances usually come through peer reviewed science not blogs or books.
Concentrating on one study the way you do only reinforces the view that McIntyre is simply trying the lawyers gambit of reasonable doubt rather than the scientists method of testing hypothesis and refining theories.
As usual Arnost, great posts, and one of the main reasons I come back and read this site when Ihave time. Please keep it up!
regards Toby
Thanks Toby
Ender, thanks for the effort you put in. Hope you don’t mind if I also reply in detail.
I have two issues with “Your real COMPLAINT is that MBH didn’t get the SMOOTHING PARAMETERS right first time.”
1) That’s not my complaint at all – my complaint is that the MBH Bristlecone pine proxy series is one of a very few that gives a flat paleoclimate / temperature and a warming in the modern times, and it is used over and over again. Using Principal Component Analysis, i.e. giving selected “important” components of a multi-component study a higher “weight” will naturally skew the result towards this component. The BCP in MBH was PC1 – i.e. the one with the highest weight thus overpowering the others.
2) There are two things wrong with “smoothing of parameters” in that a) it sets up bias in that you select which parameters a selected smoothing enhances or suppresses and thus potentially providing a false trend, and b) it assumes you have all the parameters in the first place.
Your statement “Natural factors … (are) … dwarfed by the much larger greenhouse forcing” is of course the mantra that is constantly offered as a call to action.
If I may point out, the level of understanding of the clouds, sun etc according to the IPCC is “low”. Can I therefore ask how come YOU are so sure? Please consider the following in your answer:
This is fig 9.5 from AR4 ch9 page 684: http://i16.tinypic.com/62h10xw.jpg The graph on the left (a) is reconstructed natural + anthropogenic forcings and the graph on the right (b) is natural forcings only. Neither reconstruction accounts well for the +/- temperature anomalies from 1905 –1945, whilst the natural + anthropogenic reconstruction fits the period post 1950 like a glove. So what forcings are missing / underrepresented in the first half of the century, and what is the likely effect of the inclusion / increasing of these on the “like a glove” fit in the latter part of the century?
“You have no evidence the MWP was anything other than an event confined to Northern Europe. You have no evidence to claim that it was warmer than today.”
You are entirely correct – this can not be PROVEN. But by the same token you have to admit that it can’t be proved that it WAS COLDER than today either. However, my “opinion” that it was warmer is supported by multiple independent proxy reconstructions (with some as I pointed out above using the same BCPs that are the MBH PC1) PLUS eyewitness records, agricultural records, tree line movements, stumps emerging from under glaciers, etc etc. Your “opinion” is based on a handful of studies that seem to overly rely on the MBH BCP series. Remember – most icecores and boreholes on their own show an elevated MWP or do not show an elevated modern period…!
“This is obviously ridiculous as humans have only been around for 100 000 years or so so your statement that the existence of MWP casts doubt on the present warming being caused by human greenhouse emissions is plainly wrong.” Does not follow as is – can you please clarify?
“If MBH had never decided to sort out what information they could glean from a mish mash of tree ring data and never had published MBH98 and then MBH99 then this would have made absolutely no difference to the case for AGW or the needed action to mitigate AGW”.
We can disagree. However I think that MBH is the one of the principal supports for AGW. Without it diminishing the past temperature fluctuations, there would be a very obvious need to explain these – which presently is not / can not be done – and to rule them out as not applying today.
“Often explaining or reconciling the holes is where science really advances.”
Couldn’t agree more … But first you have to find the holes – I guess that there is a space for the McIntyres of the world?
“However such advances usually come through peer reviewed science not blogs or books.”
A lot of times it also comes as a consequence of a lateral insight from an unrelated field – hence the issue that Wegman had with MBH and climate science as a closed cotterie. Also, Origin of Species, On the Revolutions, Astronomia Nova, Principia Mathematica, and many many other landmark insights that forced scientific paradigm shifts (see the book Structure of Scientifc Revolutions) were published as books. Look – peer review is not done PRIOR to publication – it is really done AFTER publication when all and sundry can pick holes and falsify (see the book Logik der Forschung). The medium of publication is irrelevant, it is the content that counts.
cheers
Arnost
So Arnost how about evolving the argument. You’ve written more than a guest post already.
Where we need to get to is what’s left when you discard what you’re unhappy with.
We also need to know if we have a solar MWP driver – otherwise you’re left with how much internal variability the climate system can have without significant external perturbation or massive internal volcanism.
Come on Arnost. Give up some decent sceptical material for a change.
I find it extraordinary that Ender can dismiss the concept of reasonable doubt as some sort of “lawyers gambit”. Reasonable doubt goes to the very essence of our notion of truth based on the fullest possession of the facts. It governs our use of assumption, to ensure that wherever assumptions are made, they are first and foremost, reasonable ones.
More importantly, it protects all of us from injurious affection from unreasonable acts that have been justified by unreasonable assumptions and unreasonable conclusions formed by a partial or fragmentary grasp of the facts.
And the fact that the climate mafia can regard this notion with contempt, as if it were some boorish inconvenience, some tedious obstacle, thrown in by saboteurs no less, makes it clear that they have a far more sinister potential than they would ever have us believe.
Arnost – “Nothing of the sort – he just wanted dodgy science exposed.”
For some reason he never questions Christy and his satellite records, despite the long history of errors from this source.
Arnost:
1) The peer reviewed literature disagrees with you and M&M criticisms have not passed peer review. What the current analysis says is that:
“Proxy-based Northern Hemisphere Surface Temperature Reconstructions:
Sensitivity to Method, Predictor Network, Target Season, and Target Domain
Rutherford, S.1*, Mann, M.E.2, Osborn, T.J.3, Bradley, R.S.4, Briffa, K.R.3, Hughes,
M.K.,5 Jones, P.D.3
We conclude that proxy based temperature reconstructions are robust with respect to a wide array of alternative statistical approaches.”
Now if you can dispute the 69 pages of science then write the paper and get it peer reviewed and published.
2) You have to do something to extract a signal and that is to suppress the noise. I don’t see the problem here.
“So what forcings are missing / underrepresented in the first half of the century, and what is the likely effect of the inclusion / increasing of these on the “like a glove” fit in the latter part of the century?”
In the first half of the century the sun did increase in output and then remained fairly constant and is now dropping slightly. There are no missing forcings as the increase in the suns activity in the first half plus the increased negative forcing of increased aerosols kept the warming to what you see. In the latter half of the century the greenhouse forcing really started to overwhelm the other forcings, positive and negative and you get the graph that you see. I rally do not see how this advances your argumenat at all.
“You are entirely correct – this can not be PROVEN. But by the same token you have to admit that it can’t be proved that it WAS COLDER than today either.”
I don’t care either way. You are the one making a song and dance about the MWP. As I realise that temperature events can be natural as well as man made I have no problem with the MWP. I do have a problem with claims that it was global that it was warmer than today. I object to such claims being made with so little evidence.
If you have 5 bodies in the morgue 4 of which died of heart attacks and the fifth of a gunshot wound do you then conclude that the fifth also died of a heart attack and ignore the gunshot wound? This is plainly ridiculous
Similarly if you have a range of climate events both warm and cold occurring naturally long before humans ever came about and one happening now when human activity is emitting known greenhouse gases that are known to affect the climate and then conclude that like all the others, including the MWP, that this one must be natural as well ignoring the gunshot wound of anthropogenic greenhouse emissions and is equally ridiculous.
“Couldn’t agree more … But first you have to find the holes – I guess that there is a space for the McIntyres of the world?”
Yes as long as they get the stuff checked first and write material that is both scientifically accurate and can be peer reviewed, something that McIntyre has failed to do and therefore advances science not one little bit.
The volumes that you speak of was the peer reviewed literature of the day – they just did it differently.
The hockey team doesn’t agree with you Arnost.
Ender seems to think this is relevant information.
Personally I think it’s a badge of honor.
James – “The hockey team doesn’t agree with you Arnost.
Ender seems to think this is relevant information.
Personally I think it’s a badge of honor.”
So Arnost and you are presenting a critique of the paper and submitting it for publication I guess from your sneering tone.
Perhaps you should put up or shut up.
Ender – McIntyre has already looked at Rutherford et al 2005 over on climate audit.
Paul – “Ender – McIntyre has already looked at Rutherford et al 2005 over on climate audit.”
And has published this in the peer reviewed literature?
McIntyre’s latest post highlights some of the issues with MBH 98/99. The Abaneh thesis is a PhD dissertation reviewed by Malcolm Hughes (the H in MBH). And PhD reviews are about as detailed as they get pre-publication.
This post highlights the cherry-pick in MBH with which I – and a lot of others – have an issue.
http://www.climateaudit.org/?p=2371
It’s worhtwhile to go through previous threads on the Abaneh issue in CA. Interesting things emerge. And I feel sorry that she has to be draged through this without being given the opportunity to reply.
It is of course interesting that nobody realy tries to defend against McIntyres findings any more. Used to be that the scientists involved used to post comments in the CA thread on the topic and RC posted replies… Now they just, like Ender/SJT, dismiss the work as crank simply becasue it’s from McIntyre and on a “blog”.
Its sad really that this does not happen. But I repeat – it’s not the medium but the content…
The problem, Arnost, is “is it science”. Science is what got us here. When it tells us something we don’t want to hear, then it’s time to abandon the scientific method, apparently, so we can hear alternative views that are not arrived at using the scientific method.
Arnost – “It is of course interesting that nobody realy tries to defend against McIntyres findings any more. Used to be that the scientists involved used to post comments in the CA thread on the topic and RC posted replies… Now they just, like Ender/SJT, dismiss the work as crank simply becasue it’s from McIntyre and on a “blog”.”
Well thats what happens if you cannot back up your rantings with peer reviewed science. The scientists depart to converse with other scientists leaving the cranks behind.
Mr Ender at November 12, 2007 08:37 AM
Try this instead:
http://www.sciencedaily.com/releases/2007/03/070327122328.htm
You must be joking! You cite a Velicogna cherry-picking study of a few years at the end of another decade+ precedent study with the opposite trend. And after you were just warned (slapped) upside the head for the same thing re: the Antarctic Ice Sheet?
Did you even look up and read the Johannessen’05 and Davis’05? ARE WE NOT DISCUSSING C-L-I-M-A-T-O-L-O-G-Y? You really should quit grasping at Dr Velicogna’s short (year) straws, especially when her ~11cm/year reduction was already surpassed in reported year-to-year fluctuations in Johannesen’05 that detailed Greenland Ice Sheet GROWTH!
Really Mr Ender; this reflexive flailing is approaching the silliness of Lil’ Lukefish. Get hooked like that again, and you’re assigned to the same aquatic school.
Good point, mccall. Both Ender and Luke were advised of Johannessens work in a thread some six months ago as well. But it met with similar response. The standard vaudeville shuffle and a massive cut and paste of off topic material to avoid the issue. The tighter the corner they find themselves, the larger the cut and paste in response.
What a smarmy bunch of dishonest gimps. McCall simply requoting cherry-picked drivel that he’s posted elsewhere in the blogosphere. A fawning Mottsa confidently agreeing with McCall on what he hasn’t even read. And you will be getting a larger than normal cut n paste to illustrate what a total ignoramus you are.
For if you had read it you would know that it stated:
Nonetheless, as mentioned, the NAO can
explain about three-quarters of the surface
elevation changes, leaving us to speculate on
other factors. A modeling study (30) of the
Greenland Ice Sheet mass balance under greenhouse
global warming has shown that temperature
increases up to 2.7-C lead to positive
mass-balance changes at high elevations (due to
accumulation) and negative at low elevations
(due to runoff exceeding accumulation), consistent
with our findings, which implies that
perhaps a quarter of the growth may be caused
by global warming in Greenland (31) in our
observation period. Furthermore, the observed
elevation change implies that ice-sheet growth
in the interior of Greenland may partly offset
the freshwater flow of the retreating subpolar
glaciers needed to explain the freshening rate of
the world ocean, which can be explained almost
entirely by Arctic sea-ice melt (32).
In conclusion, we have presented new evidence
of (i) decadal increase in surface elevation
(È5 cm/year) within a study area
comprising most of the Greenland Ice Sheet,
1992 to 2003, caused by accumulation over
extensive areas in the interior of Greenland;
(ii) divergence in elevation changes since the
year 2000 for areas above and below 1500 m,
with high-elevation increases and low-elevation
decreases, the former in contrast to previous
research (10, 13); and (iii) negative correlation
between winter elevation changes and the NAO
index, suggesting an underappreciated role of
the winter season and the NAO for elevation
changes—a wild card in Greenland Ice Sheet
mass-balance scenarios under global warming.
There are, however, caveats to consider.
First, we cannot make an integrated assessment
of elevation changes—let alone ice volume
and its equivalent sea-level change—for the
whole Greenland Ice Sheet, including its outlet
glaciers, from these observations alone, because
the marginal areas are not measured
completely using ERS-1/ERS-2 altimetry (see
Fig. 1). It is conceivable that pronounced
ablation (e.g., 10, 11) in low-elevation marginal
areas could offset the elevation increases
that we observed in the interior areas. Second,
there is large interannual to decadal variability
in the high-latitude climate system including
the NAO, such that the 11-year-long data set
developed here remains too brief to establish
long-term trends. Therefore, there is clearly a
need for continued monitoring using new satellite
altimeters—including advanced ones with
improved ice-sheet ranging in steeper coastal
areas—and other remote-sensing and field observations,
together with numerical modeling
to calculate the mass budget through net losses
and net input from snow (33)..
He might also know that:
Our results show that the East Antarctic
ice-sheet interior increased in overall thickness
within the ROC from 1992 to 2003 and that
this increase is probably the result of increased
snowfall. Both of these observations are consistent
with the latest IPCC prediction for Antarctica_
s likely response to a warming global
climate (6). However, the IPCC prediction
does not consider possible dynamic changes in
coastal areas of the ice sheet. Moreover, these
results have only sparse coverage of the coastal
areas where recent dynamic changes may be
occurring (4). Thus, the overall contribution of
the Antarctic ice sheet to global sea-level
change will depend on the balance between
mass changes on the interior and those in
coastal areas.
Hmmmm – not as cut & dried as our McGraw chicken hawk would make out. What a bullshit artist.
Students of the literature might also have read a more recent review such as Shepherd et al above which states:
After a century of polar exploration, the past decade of satellite measurements has painted an
altogether new picture of how Earth’s ice sheets are changing. As global temperatures have risen,
so have rates of snowfall, ice melting, and glacier flow. Although the balance between these
opposing processes has varied considerably on a regional scale, data show that Antarctica and
Greenland are each losing mass overall. Our best estimate of their combined imbalance is about
125 gigatons per year of ice, enough to raise sea level by 0.35 millimeters per year. This is only a
modest contribution to the present rate of sea-level rise of 3.0 millimeters per year. However, much
of the loss from Antarctica and Greenland is the result of the flow of ice to the ocean from ice
streams and glaciers, which has accelerated over the past decade. In both continents, there are
suspected triggers for the accelerated ice discharge—surface and ocean warming, respectively—
and, over the course of the 21st century, these processes could rapidly counteract the snowfall
gains predicted by present coupled climate models.
But as usual our Neo-Raphaelite rhetorical raconteur has missed the overall philosophical import of a wider view on the issue:
At the same time, the very variability that
these recent studies have revealed is the reason
why short-term records, no matter how
detailed, are so poorly suited to providing projections
of future change. To use a simple
analogy, they are measures of weather rather
than climate. In fact, in some instances, this is
not far from the truth. For example, the
recent precipitation-driven thickening of
the Greenland ice sheet is apparently linked to
the negative phase of the North Atlantic
Oscillation (NAO) which dominated during
the period of observation (Johannessen et al.,
2005). This is in direct contrast to previous
decades, and future predictions suggest the
NAO will become increasingly positive as climate
warms (Osborn, 2004; Kuzmina et al.,
2005), reversing this thickening trend. For
these kinds of reason, there is now some discussion
as to whether the late Holocene in general, and instrumental data in particular,
are the most appropriate basis from which to
infer future change (Henderson, 2005;
Kennedy and Hanson, 2006).
An alternative is to examine records from
previous interglacials, which provide a longer term
context against which more recent
changes can be assessed. The last interglacial
(LIG) has attracted particular attention as
Arctic temperatures were warmer, sea levels
higher and the Greenland Ice sheet smaller
than present. For example, Overpeck et al.
(2006) use a coupled ocean-atmosphere climate
model to simulate LIG climate and compare
this with simulations of the next 140
years to examine potential ice-sheet contributions
to sea-level rise. Their results suggest
that by 2100 the Greenland region will be at
least as warm as it was during the LIG and, by
implication, warm enough to melt large portions
of the Greenland Ice Sheet. Similar
results are suggested by Otto-Bliesner et al.
(2006) who use a global climate model, a
dynamic ice sheet model and palaeoclimate
data to evaluate LIG Arctic warming. Their
data suggest that retreat of the Greenland Ice
sheet and surrounding icefields can contribute
2.2–3.4 m of sea-level rise over 2000–3000
years.
The question of whether recent ice-sheet
changes are the first indications of possible
future trends cannot be resolved with existing
data. However, a study of marine sediments
in Antarctica suggests that the recent
breakup of a portion of the Larsen Ice Shelf is
unprecedented in the context of the
Holocene (Domack et al., 2005). A possible
cause is undermelting from warming ocean
waters (Shephard et al., 2003), and new
oceanographic data show signs that such
recent warming has occurred (Barnett et al.,
2005), although, critically, data coverage from
high-latitude seas is relatively poor (Hegerl
and Bindoff, 2005).
If nothing else, both instrumental and geological
data reinforce the fact that cryospheric
(and sea-level) change cannot be predicted
from simple indices such as temperature, and that
past changes have sometimes happened
abruptly (eg, Rinterknecht et al., 2006). They
also highlight the inadequacy of representing
future change as two-dimensional, despite
the iconic nature of certain x-y plots. This
‘deadening of environmental space’ as Lane
(2005) puts it, is something that must be
addressed if predictions of future change are
to be viewed with any degree of security. The
combination of satellite and tide-gauge data is
an example of one of the ways in which this
may be achieved (Church and White, 2006).
Gee eh? Is that so…
Your sneering trivialisation and ignorance of this whole research area is pathetic.
McCall – just another denialist mental midget.
Q.E.D. Mr Mott: “The standard vaudeville shuffle and a massive cut and paste of off topic material to avoid the issue. The tighter the corner they find themselves, the larger the cut and paste in response.”
Lil’ Lukefish gets hooked again; and in the very next post, as he puts up a circular argument WHOPPER without realizing it. Lukefish — the Antarctic temperature anomalies are FLAT TO COOLING FROM 1979-PRESENT … Greenland’s are the opposite, though still not to the level of the 1930s and early 40s warming! And I will bet you right now, that 2007 will go down with Antarctic anomalies among the coolest of the period. Not only do you misunderstand the AGW theory (of everything); but like the truly ignorant physical science guppy you are, you continue to flail on a circular argument.
BTW, hilariously predictable try with the giant Shepherd “Cut & Paste” shifting away from Davis, Johannessen, and Velicogna… I know Mr Mott is enjoying himself. Oh well, at least Dr Shepherd expressed the weather vs. climate flaw (of Veligogna among others) current arguments, even if you missed it.
Mr Ender — have you engaged your cloaking device?
McCall – cripes he doesn’t even know – I’m laughing even more widdle chicken hawk as I have posted from Davis and Johannessen – which you obviously haven’t read either.
All of these guys have warned about being definitive and have fully discussed everything we’re on about. But you only read the abstracts quoted from one of the many shonk centrals didn’t you.
As for cooling in the larger part of the continent (except on the Peninsula), well depends who you cite but yes it isn’t warming rapidly, which is exactly what you expect numb nuts as AGW changes SAM. Are you that stupid. I am really quite stunned.
You might also tell us why the troposhere above Antarctica is warming almost faster than anywhere.
“Oh didn’t know that” as chicken hawk get squashed by an ice flow falling apart. I’m also stunned that as a cherry picker you’re blatantly cherry picking yourself. Lots of decadal masking and a long ways to go.
Chicken hawk (demoted from Quickdraw) forgets to mention that the interim AGW position would be to see exactly what we’re observing in an locally intensified hyrdrological cycle balancing out coastal erosion.
But lets wait for a drivelly Neo-Raphaelite rhetorical serve from our journal reading property rights pugilist. Should be good.
McCall I just realised that you’re pretty junior in this whole field. For a while I thought you might have known something. Next time you go fishing mate take Marlin tackle and a higher breaking strain.
Hunter becomes the hunted. But I wouldn’t bother – chicken hawks not much use except for bait.
I say I say I say boy.
ROTFL and LMAO.
And I just realised who Foghorn is …. oooo LOL
(SJT and Ender – I told you they were flakes. You can always count on Motty not to have read it too. Easy marks.)
Mccall – “Mr Ender — have you engaged your cloaking device?”
No I have this thing called a life. You should try it sometime.
From Luke’s cut’n past above, “Their results suggest that by 2100 the Greenland region will be at least as warm as it was during the LIG and, by
implication, warm enough to melt large portions
of the Greenland Ice Sheet. (How large you ask?) Similar results are suggested by Otto-Bliesner et al. (2006) who use a global climate model, a
dynamic ice sheet model and palaeoclimate
data to evaluate LIG Arctic warming. Their
data suggest that retreat of the Greenland Ice
sheet and surrounding icefields can contribute
2.2–3.4 m of sea-level rise over 2000–3000
years.”
Now lets see now, 3.4m of sea-level rise is half the total ice sheet in 3000 years. And that would work out at (3400mm/3000) 11cm per century.
So these “large portions of the Greenland Ice Sheet” that are supposedly capable of being melted by 2100 will actually only amount to, at most, 1.6% of the ice sheet.
Now one cannot speak for everyone but we can state that the term “large portions” refers to the size of a portion in relation to the whole. And to use such a term to describe a portion that only amounts to 1.6% of the whole is highly misleading. It is a deceptive term in this context, and is either negligently so or deliberately, deceptive.
Luke’s own cut and paste job makes two things clear.
1. Contrary to the Author’s claim, “large portions of the Greenland Ice Sheet” will not melt by year 2100, and
2. Researchers in this field are prone to use exagerated terminology that reasonable men and women, in possession of the facts would not use when forming their conclusions on the evidence.
Looks like McCall has done a runner.
Luke,
Have you seen / read the new Loehle E&E (cringe) paper…?
http://www.ncasi.org/publications/Detail.aspx?id=3025
I’ve only skim read it… but already have an opinion. I’m interested in yours. (and without the flowery language please).
cheers
Arnost
Nope – but have now – very interesting.
But we must wait for McIntyre’s approval and total audit !!
Hard to say Arnost without contemplating a while and without seeing some paleo community reaction.
I did note:
“I am also curious why your plots seem to end around 1970 instead of 2000.”
and
“Now the real question is – how robust is your reconstruction? Without seeing the individual constituent proxy records, it is difficult for a reader to make a site-by-site assessment of MWP vs. present conditions. Also – as #9 notes above, the method you used could introduce bias when comparing MWP and present conditions. As I am sure Steve will tell you, some of your proxies may not be ‘true’ temperature proxies either.
If your series is robust, it would have major implications for attribution studies. However, by “giving” up after rejection from GRL and going for E+E, it is quite likely that your series will never be taken seriously.”
E & E sigh … wonder what GRL’s objection was?
Anyway Arnost you tell me !
Re: Lil’Lukefish at November 15, 2007 09:16 AM …
Wow! You can’t be that dumb; one hopes you warmed up, before you made that freaking stretch? A fantasy gotcha on my, “BTW, hilariously predictable try with the giant Shepherd “Cut & Paste” shifting away from Davis, Johannessen, and Velicogna…”post; have you always had difficulty reading/understanding English? And I mistakenly thought Mr Hissink was exaggerating (well, more about that hypothesis later).
First a little intro to help frame Lil’ Lukefish’s claim, “I have posted from Davis and Johannessen” — refers to the post:
Lil’ Lukefish at November 15, 2007 09:54 PM – a.k.a. THE MOTHER OF ALL CUT”n”PASTE (CnP) POSTS!
CnP 1: begins “Nonetheless, as mentioned, the NAO can…” Lil’s long ~50% CUT’n’PASTE from Johannessen’05
Science 11 November 2005: Vol. 310. no. 5750, pp. 1013 – 1016 NOTE: more on this below!
CnP 2: begins “Our results show that the East Antarctic…” Lil’s short summary paragraph cut’n’paste of Davis’05
Science 24 June 2005: Vol. 308. no. 5730, pp. 1898 – 1901
CnP 3: begins “After a century of polar exploration…” repost of Lil’s earlier Shepherd’07 abstract-only cut’n’paste
Science 16 March 2007: Vol. 315. no. 5818, pp. 1529 – 1532
CnP 4: begins “At the same time, the very variability that…” Lil’s long ~40% CUT’n’PASTE from Edwards’06
Progress in Physical Geography 30, 6 (2006) pp. 785–796
Note 1: for clarity, references for CnP’s 1, 2, and 4, were added by me! Lil’ Lukefish did attribute cut’n’paste 3 earlier in thread, and simply reposted after Mr Mott filleted him. It’s obvious that Lukefish understood neither the paper, nor Mr Mott’s arguments.
Note 2: Lil’ Lukefish sets record – serial-parroting 4 cherry-picked cut’n’pastes in one post, all while failing to grasp their linkage.
Now back to my post of, “BTW, hilariously predictable try with the giant Shepherd “Cut & Paste” shifting away from Davis, Johannessen, and Velicogna…” that Lil’ went “gotcha” on? This sentence clearly refers to the Shepherd’07 CnP 3, plus what turns out to be Edwards’06 CnP 4! The “BTW” (“by the way,”) and “GIANT SHEPHERD” are clues, Lil’ Lukefish – as I hinted earlier, perhaps help in reading/understanding English would prevent such fantasy jumps.
However, I will correct one phrase, due to Lil’ Lukefish’s (Shepherd’07 abstract-only + Edwards’06) cut’n’paste deception:
“Shepherd expressed the weather vs. climate flaw (of Veligona…” gets changed to
“Edwards expressed the weather vs. climate flaw (of Velicogna…”
Obviously, everything else stands – including Q.E.D. Mr Mott! Corner an AGW zealot, expect big cut’n’pastes in response.
Now on to Mr Hissink’s hypothesis…
It’s clear Lil’ Lukefish also demonstrated ignorance and (likely) deception, when he accuses me of abstract-only posts, without reading the actual papers. Ironically, this is something that is suspiciously like what he did with Shepherd’07 (abstract only), then deceptively appended Edwards’06, unattributed — a copyright sleight of hand? Maybe we’ve all come to expect such things from the desperate Lil’ Lukefish? Anyway, Lil’s abstract-only fantasy is easily dispelled to all (except perhaps Lukefish?), when one goes back to just one quote in my Velacogna critique post of November 15, 2007 12:32 PM, see
“… when her ~11cm/year reduction was already surpassed in reported year-to-year fluctuations in Johannesen’05 that detailed Greenland Ice Sheet GROWTH!”
This post refers directly to a paragraph*, more than ½-way through the Johannessen’05 paper:
“Regional temperature and precipitation are both influenced by the NAO (15)… (my emphasis) THIS IS EXEMPLIFIED BY THE CHANGES OBSERVED FROM 1994/1995 (–10.1 cm) TO 1995/1996 (+11.6 cm), ASSOCIATED WITH A RECORD POSITIVE-TO_NEGATIVE NAO REVERSAL (2.4 to –3.1) (Fig. 3).”
Note: tightly quoted, the last sentence in this paragraph, is operative support for my “year-to-year fluctuations” critique of Velicogna’s short-year study alarmism. And it definitely did not come from the abstract, as is so idiotically charged by Lil’ Lukefish. Odd how this paragraph was missing from the massive Johannessen’05 extraction that Lil’ cut’n’pasted for us – nah, the deceptive Lukefish wouldn’t have omitted it intentionally, would he? I’ll just let the rest of you judge that…
So Q.E.D. Mr Hissink, as well! Lil’ Lukefish is a “blathering idiot” – a deceptive (& perhaps copyright fraudulent) one at that!
Methinks little chicken hawk doth protest too much. At this point you’re hooked and have been dragged all over the harbour. You’re responding to me not me to you. You’re “gooooone”.
Mate you’re blathering – wipe the froth from your mouth – the arguments have been clearly made by all authors – don’t try your fraudulent methodology of dissectionism to bulldust your way out.
Arguments have been made from authors conclusions not half the story mate. And those conclusions are far from your skanky selective denialist interpretations aren’t they. I now know you’re an abstract only cherry picker.
You had your chance for a serious discussion and decided to wing it. Serious mistake. You’re a flake.
Chicken hawk swallowed by marlin. No trace….
P.S. If you’re a fan of Louis – just do one thing – just say his scientific views have your full support. We just like to hear supporting comments from friends. 🙂
Thanks Luke,
Yes, I’m also interested in SM’s response. There are already a couple of interesting points raised on CA WRT to this.
My biggest issue is that it’s only 18 proxies – which really is not a large number – on the other hand they do seem to be consistent with each other so that is a plus…
What seems to be missing from the paper – and somthing which would make it more robust – is some sort of discussion re WHY these proxies represent temperature. I am not really familiar with the papers where they first were used – will have to have a trawl through Google Scholar – but I reckon that the argument against this paper will principally come from this direction.
It also will be interesting to see how long before RC posts up a rebutal. The longer this takes will be a guide as to how difficult a rebutal will be… If they are silent on this – (well they can’t really be can they) – it will be a tacit acceptance. After all – the paper really puts to question the validity of using treerings as a temperature proxy and thus challenges tje accuracy of a lot of mainstream reconstructions.
WRT to the plots ending in the 70’s – well if that’s when the proxies end, that’s where the plots end. One of the key methodologies of the paper (and why there’s only 18 proxies used) is that you are not splicing / combining proxies.
Be good to keep an eye on this.
(Paul/Jennifer – it may be worthwhile to do a post around this one in a couple of days – especially if both Steve Mc and Gavin/Mike at RC post up on it).
cheers
Arnost
By the way, GRL sent it back unreviewed because they were “tired of seeing reconstructions”. Form Craig Loehle post 6 on the CA thread for this. Read into this what you want…
Luke
In case you are still following this thread, then an interesting take is here:
http://thatstrangeweather.blogspot.com/
Obviously Julien (Emile-Geay) has had a very quick stab at it – and I think is downplaying the point that all the reconstructions in Lohle (well maybe all but one) have been used in previously published works where they have been calibrated to temperatures – i.e. eight of the 18 are used in Moberg et al.
The argument that they are not “correctly weighted” is to me irrelevant. Loehle assumes no bias for any one proxy over any other. Which I think is fair.
As I said above, this is the first point of criticism that will be levied.
As to the lack of verification r2 statistics – this is where I think the paper will be ultimately ripped appart by the team. However, one may hope that a new paper will rise out of the ashes… Loehle’s hinting at this.
I would have just copied the paper structure identical to say this and then laughed out loud if it was criticised…
http://eas8001.eas.gatech.edu/papers/Mann_et_al-JGR07.pdf
cheers
Arnost