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The Saint
2005-Sep-28, 08:55 PM
What would be the differing world effects of the arctic ice cap completely melting over a) 1 year, b) 20-50 years and c) 100 years?
http://www.sky.com/skynews/article/0,,30000-13446042,00.html

Could human life continue without the ice cap?

Glom
2005-Sep-28, 09:58 PM
Suspicous temporal anomalies.


A joint study by the National Snow and Ice Data Centre (NSIDC) and NASA reveals that the polar ice pack has shrunk by 30% since 1978 and that melting is speeding up.

1978 eh? That's the time when the mid century cooling reversed. In other words, it has shrunk since the world stop cooling. Le shock!


The degeneration has been helped this year by the warmest Arctic summer in 400 years.

400 years eh? That's means it's the warmest since the Little Ice Age. Le shock!


By the end of the century the region is likely to be ice-free through the summer months - pushing temperatures not seen there for around a million years.

That's a prediction, not a fact. If it's from linear extrapolation then they should be bludgeoned. If it's from models, then it should be taken with a pinch of salt. Besides, wasn't the ice cap nearly gone during the MWP? I remember reading about that but can't find where.

Fram
2005-Sep-29, 11:55 AM
Suspicous temporal anomalies.

1978 eh? That's the time when the mid century cooling reversed. In other words, it has shrunk since the world stop cooling. Le shock!

400 years eh? That's means it's the warmest since the Little Ice Age. Le shock!

That's a prediction, not a fact. If it's from linear extrapolation then they should be bludgeoned. If it's from models, then it should be taken with a pinch of salt. Besides, wasn't the ice cap nearly gone during the MWP? I remember reading about that but can't find where.

1978 is the year from which they have reliable data (http://nsidc.org/sotc/sea_ice.html). You can find that suspicious as much as you like.
On the same page, they have data comparing the 1958-1976 period with 1993-1997. This gives the same image. Still suspicious?
By the way, the mid century cooling, that is the period when temperatures stayed stable instead of rising? When seen on graphs like this one (http://data.giss.nasa.gov/gistemp/2004/), this mid century cooling isn't that impressive at all, when seen on th eoverall view from 1880 till now.

worzel
2005-Sep-29, 12:01 PM
I saw this on the news the other day while I was half asleep and thought I had dreamt this 30% figure. If sea levels are supposed to rise by meters if all the ice melts, then shouldn't the level have risen by roughly a meter already due to this 30%?

Fram
2005-Sep-29, 12:15 PM
I saw this on the news the other day while I was half asleep and thought I had dreamt this 30% figure. If sea levels are supposed to rise by meters if all the ice melts, then shouldn't the level have risen by roughly a meter already due to this 30%?

No, this is about the arctic ice, which was already in the water. When ice that floats in the water melts, the water level doesn't change. The rising of the sea level would happen if the Antarctic ice, the Greenland ice, and other glaciers and so on would melt.

worzel
2005-Sep-29, 12:29 PM
No, this is about the arctic ice, which was already in the water.Thanks. Note to self: must improve my geography.

Glom
2005-Sep-29, 01:29 PM
1978 is the year from which they have reliable data (http://nsidc.org/sotc/sea_ice.html).

In that case, they have little grounds to draw conclusions about how shocking it is and they admit as much.


On the same page, they have data comparing the 1958-1976 period with 1993-1997.

Not quite. It compares the draft between those periods to demonstrate a shrinking. No surprise or dispute.


When seen on graphs like this one (http://data.giss.nasa.gov/gistemp/2004/), this mid century cooling isn't that impressive at all, when seen on th eoverall view from 1880 till now.

Well it was a mild drop in solar activity. ;)

It was obviously enough to cause another climate scare about an impending ice age.

electromagneticpulse
2005-Sep-29, 05:28 PM
If we've only had reliable data since 1978 we know nothing in the slightest. I mean hurricanes take energy out of the oceans and they think we're now going into a 40 year peak (I think it's 40 years anyway, I have a memory like well I don't know a hula hoop?) that could mean the oceans will cool and the arctic will freeze again.

Maybe all these fit into a larger global pattern that plays out over centuries, we simply don't know and scientists are simply being unprofessional and guessing. 30 years is a geological second and that would be like predicting how a football game would play out by watching a random second in the game, you wouldn't be able to tell a thing or predict anything.

I mean so the ice caps are melting boo hoo, I propose we should stop complaining so much about the environment. I mean if we can force ice caps to melt I'm sure we could hold back a couple of glaciers. Although my personal preference would be to leave this godforsaken planet as it has an extremely poor surface area to mass ratio. Plus I want to listen to some Beethoven in zero-g.

Fram
2005-Sep-29, 07:17 PM
Well it was a mild drop in solar activity. ;)

It was obviously enough to cause another climate scare about an impending ice age.

Yep. It's sad that this has caused much distrust of the AGW theory. The "cry wolf syndrome" (doesn't matter if AGW is right or wrong for this).

The Saint
2005-Sep-30, 02:39 PM
So is it correct that the Artic Ice melting over 1 year would be a very nasty surprise to all people living near or on permafrost and that it might stop the Gulf Stream, plankton etc.

Over 20 years the impact would not be so severe and people would have time to adjust but many would suffer from it.

Over 100 years there would be many old persons telling stories to their grandchildren about the North Pole and kids wouldn't believe it: where is Santa Claus going to live?!

pghnative
2005-Sep-30, 03:42 PM
I don't understand the last line of the article:

This year is expected to see the lowest amount of ice cover in more than a centuryIf the arctic has seen this low of an amount of ice cover in the past, then how do they extrapolate that things will be worse this time?

I suppose the answer is "because this time humans are at fault", but I don't see how this observation adds to the debate. If the ice cover has been this low in the past when humans weren't at fault, then why are we shocked that it's happened again?

Perhaps if the rate of decrease were statistically different than in the past, but I'm not sure we have enough data to assess that.

pghnative
2005-Sep-30, 03:43 PM
where is Santa Claus going to live?!He'd have enough time to outsource to Antarctica

electromagneticpulse
2005-Oct-01, 12:13 AM
I don't understand the last line of the article:
If the arctic has seen this low of an amount of ice cover in the past, then how do they extrapolate that things will be worse this time?

I suppose the answer is "because this time humans are at fault", but I don't see how this observation adds to the debate. If the ice cover has been this low in the past when humans weren't at fault, then why are we shocked that it's happened again?

Perhaps if the rate of decrease were statistically different than in the past, but I'm not sure we have enough data to assess that.

No the real question is if we've only had reliable data for 30 odd years then how the heck do they know what the ice cover was like more than a century ago? We're working with Llama's here, yes Llama's. I would have said monkeys or apes but they can use tools and would probably be doing a better job as I doubt they have the concept of guessing yet and I also doubt they have the phrase "Oh my God, who removed these peoples brains?!"

Personally I would trust a magic eight ball to give a more probable result; I mean the things are never wrong.

Oh and I thought Santa Claus lived in Lapland. Can't we just have fun telling kids that Santa is dead and then they won't care if the arctic melts or not.