Glacier Dynamics and Why Greenland Not in Danger of Collapse

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.

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.
http://www.youtube.com/watch?v=-o9rrjMZ_48

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.)

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.

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.

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.