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have a full subscription to SCIENCE, and we read, and re-read the article in our bath,last week, and macerated its strange reasoning in my head. But the pictures of this cover story were great.

BTW, the article is ominous about the fate of West Antarctica:"INHERENTLY UNSTABLE" (first sentence of the article!).

Then I looked at the pretty pictures, and looked again, and looked on the side, where East Antarctica, most of Antartica, is found. How interesting.

There I saw a positively enormous area where the icecap bottom is LOWER than 200 METERS BELOW SEA LEVEL.Yes 200 meters below! Imagine the disaster when warm water is going to slip below that...

Thus, if anything, I found the conclusions scarier than ever. I want to see an article incorporating all what can blow up in a flash of steam in EASTERN ANTARCTICA. Now. Methinks it's got to be of the order of twenty meters of seal level rise, just looking at it.

So thank you science, thank you lord, and let's be real nomads, and run for the hills!

A bad emotion reinforced by a little bit of the wrong knowledge often spells disaster.

PA

Patrice Ayme Patriceayme.com Patriceayme.wordpress.com http://tyranosopher.blogspot.com/

by Patrice Ayme on Sat May 23rd, 2009 at 04:43:38 PM EST
So let's not get all emotionally charged, don't run for the hills just yet, and start building a durable planet instead.
by Nomad (Bjinse) on Sat May 23rd, 2009 at 05:20:35 PM EST
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The Fates are kind.
by Gaianne on Thu May 28th, 2009 at 06:57:22 PM EST
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If you are young or middle aged and planning for retirement by the sea, it might be prudent to look for something, say, 8-10 meters above sea level.  And while nonlinear processes could result in melting faster than current projections, it is unlikely that any process, other than a large meteor impact, could bring about a rise of even a meter in  a couple of years.  But one wouldn't want to try to sell one's retirement home when water is lapping at the front step. To me a one meter+ rise is quite conceivable, and perhaps likely, over a forty year period.  

"It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Sat May 23rd, 2009 at 05:51:02 PM EST
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The problem has nothing to do with one particular parameter of the possible, for example sea rise.  When all forms of ecosystems are now subject to irreversible damage, it's the totality of the effects which must be considered.  Who cares if the sea rises 1 or 3 or 5 meters if the basic foodstuffs are damaged by this civilization, if the destruction of genetic diversity leaves us hanging by our primordial toes, if the destruction of coral reefs is a symptom that even a higher sea has nothing to harvest, then it doesn't matter where you live.

"Life shrinks or expands in proportion to one's courage." - Ana´s Nin
by Crazy Horse on Sat May 23rd, 2009 at 06:12:01 PM EST
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Patrice Ayme Patriceayme.com Patriceayme.wordpress.com http://tyranosopher.blogspot.com/
by Patrice Ayme on Sat May 23rd, 2009 at 08:02:01 PM EST
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Certainly true.  The comment about selling your retirement home was a bit facetious.  Even with a +4C rise in temperatures we are likely to have other problems as bad as sea level rise.  Most basically, we could have a significant reduction in the carrying capacity of the earth.  

"It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Sat May 23rd, 2009 at 08:05:58 PM EST
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such as me, thinks that one meter is certain, but as much as 25 meters is possible by 2100 (more importantly, so does NASA's Hansen). Too many highly non linear guns in the face (methane, albedo). The planet is going to try to trsnsfer heat to the poles with even more enthusiasm, so melting is going to accelerate.
PA

Patrice Ayme Patriceayme.com Patriceayme.wordpress.com http://tyranosopher.blogspot.com/
by Patrice Ayme on Sat May 23rd, 2009 at 07:58:29 PM EST
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ARGeezer:
To me a one meter+ rise is quite conceivable, and perhaps likely, over a forty year period.

And Patrice seems to suggest he is as pessimistic about this. What are your reasons/thoughts behind this?

I ask because there are at least two groups that I know which do not think this is likely. The first the AR4 from the IPCC, the second the Dutch water boards. My uncle used to work for the latter, and the consensus remains that for 2100 the Netherlands will not face a 1 meter rise of sea level.

Granted, I'm one of the first to say that in climate change we don't know what we don't know, and a lot uncertainty remains, but on what is this pessimism based?

by Nomad (Bjinse) on Sun May 24th, 2009 at 08:13:07 AM EST
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radiative output (6% in some wavelenghts, it is claimed!)
Sun has got to be worshipping coal and Pluto.
Absent this solar silliness (demonstrated by fewer sunspots in a century), I gave the reasons  above for a considerable sea rise.

Moreover, upon warming I see a reason for the EAST Antarctic basins to melt. They front the sea at the polar circle (i.e., way far from the pole).

I will put all this together in a post on patriceayme.wordpress.com... But I can't believe the sun... Will not save us, because if the CO2 keeps on going up, the oceans will turn into diluted lemon juice...
PA

Patrice Ayme Patriceayme.com Patriceayme.wordpress.com http://tyranosopher.blogspot.com/

by Patrice Ayme on Sun May 24th, 2009 at 10:47:43 AM EST
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but on what is this pessimism based?

In my case, I am pessimistic that we, as a species, will be able to act with sufficient alacrity to avert ambient temperature increases of 2-4C, or possibly more.  The collective reporting I have seen on the Greenland and West Antarctic Ice Sheets, combined with what I have read about the probable rapid rate of melting of the North American Ice Sheet at the beginning of our current epoch, leads me to doubt that extrapolations of melt rates for these ice sheets will follow current linear models.  

I fear current models assume that the ice sheets will melt in place and perhaps the rate of calving of icebergs into the ocean will increase at about the rate of increase we have recently observed.  Were you able to inform me otherwise I would be relieved.  I am concerned that recent reports of melt water toward the center of these ice sheets creating channels to bedrock will increase and will increase the rate of motion in second order or higher ways.

I think it is more likely that we will document accelerating  processes at work within a decade or so than that we will confirm existing models.  I have no way of knowing how fast melting will occur, but a one meter rise seems much more likely to me than a 10cm rise by mid-century.  I am also concerned that responsible and competent authorities are not creating models that are based on accelerating melt rates and ice movement and using them to evaluate which model best fits observation.  If they are and if they have published results, I have missed the report.

We have all deplored the extent to which Bush era science was subjected to political censorship.  But I do not think that this problem has vanished with the change of one administration in one country.  Nor do I think that current estimates err on the side of pessimism.  To me the question is how much less optimistic should we be.  

"It is not necessary to have hope in order to persevere."

by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Sun May 24th, 2009 at 01:03:24 PM EST
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who is saying what. Sun seems confused too. I gave above new reasoning for 25 meter rise. But if the sun slows down seriously, that's out of the window, we will know soon. I will put things in an essay, to kill time before my next publication of Qur'an selects...
;-)!

Patrice Ayme Patriceayme.com Patriceayme.wordpress.com http://tyranosopher.blogspot.com/
by Patrice Ayme on Mon May 25th, 2009 at 02:28:18 AM EST
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I'm pessimistic because I suspect that the ice shelves are being modelled as more stable and warming-resistant than they really are. A while ago I wrote:
A lot of the climate models seem to have modelled the ice sheets as ice cubes when they behave more like a drop of honey. Ice cubes are very poor heat conductors, insulate their own interior, and only melt on the surface. A drop of honey gets less viscous and flows more easily as it warms up. But I am not an expert on climate modelling.
ARGeezer:replied with
Lately I have been reading articles in Science News and elsewhere about glacial lakes melting holes through very thick glaciers and disappearing through said holes. It appears that this additional water further lubricates the interface between the ice and the rock below, increasing the rate of glacier flow.
I was recalling an article we had discussed in the Salon a couple of years back where some climate scientists suggested that the "ice cube" model used in climate simulations led to melting times of the order of 1,000 years whereas the actual dynamics of the ice shelf might lead it to disintegrate on much shorter timescales.

Then I have seen footage of how meltwater pours into deep crevasses in the Antarctiva ice sheet, going directly to the bedrock where it lubricates the interface between the ice and the rock. I am not convinced large chunks of the Antactica ice cap couldn't simply slide into the sea as a result of this lubrication.

The brainless should not be in banking. — Willem Buitler

by Carrie (migeru at eurotrib dot com) on Mon May 25th, 2009 at 06:32:49 AM EST
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of the geologist, I think that's too pessimist. For now. Don't understand me wrong, if global temperatures creep up another 2 degrees, we are in deep serious - which is why business-as-usual GHG emissions cannot hold.

A few responses up, nanne actually links to one of the articles that illustrate the point, namely:

  1. as far as has been determined, current global temperature is still cooler than the Holocene climatic optimum - particularly in the northern hemisphere.

  2. the last interglacial period (prior to this one) did have 4 - 6 meters higher sea level - but temperatures were an estimated 2 degrees higher. See here and here for examples I've found quickly.

Looking at temperature correlations, we may be seeing calving reaching a new equilibrium and grow constant but on the condition that temperatures stablise.
by Nomad (Bjinse) on Mon May 25th, 2009 at 09:52:25 AM EST
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Nomad:
Don't understand me wrong, if global temperatures creep up another 2 degrees, we are in deep serious - which is why business-as-usual GHG emissions cannot hold.
On that note:



The brainless should not be in banking. — Willem Buitler

by Carrie (migeru at eurotrib dot com) on Tue May 26th, 2009 at 04:12:27 AM EST
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are still something else: bottom is below sea level. Way below. my hunch is that if ocean temps get above a threshold, the WAIS will disintegrate instantaneously.

Patrice Ayme Patriceayme.com Patriceayme.wordpress.com http://tyranosopher.blogspot.com/
by Patrice Ayme on Tue May 26th, 2009 at 07:46:59 PM EST
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