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**GordMay** · 19-08-2008, 10:35

Quote:

Originally Posted by gonesail

y... a recent NASA picture showed that in fact the arctic ice cap is actually growing over the last several years...

WRONG !!!

Not only is the Arctic ice cap shrinking, it is shrinking at a pace that places its disappearance two to three decades ahead of the gloomiest previous forecasts. It is now generally predicted that the Arctic ice cap will totally disappear in 20 - 25 years, leaving the Arctic Ocean totally free of summer ice as early as the summer of 2030. Some scientists even predict that Arctic summer sea ice will totally disappear as early as 2015. The previous most dismal prediction of the Intergovernmental Panel on Climate Change had the Arctic ice cap vanishing by the year 2050.

The Arctic ice cap’s area of coverage is not only shrinking. It is also getting thinner. It occurs all across the Arctic Ocean. Each year, as the cycle goes, Arctic ice freezes in the winter and reaches its maximum size, or extent, in early March and is at its smallest point in September. In 1991, the summer Arctic ice was about 10.2 feet thick (ice pack thickness is measured from sea level to the bottom of the ice pack). Since 2001, the thickest areas of Arctic ice have thinned to three feet, less than a third of the 1991 ice cap and half of its 2001 thickness. In some areas, the thickness is six inches or less. Yet, the ice above the sea level (called “freeboard”) in the spring of 2008 is about two to four inches less than it was in spring 2007.

According to images captured by NASA's QuikSCAT satellite, the Arctic icecap has lost at least 14% of its 'perennial' ice between 2004 and 2005. Data shows that at least 280,000 square miles of ice, at least the size of Texas has been lost. The eastern Arctic has lost at least 50% of its ice, but scientists say that ice was shifted by wind and other weather factors from the east to the west Arctic, causing the western areas of ice to actually grow.

The Arctic ice cap reached its smallest extent ever in 2007 (below, top), about 50 percent of its size in the 1950s. The image beneath it shows the ice cap’s average area in 1979-1981. (NASA images)

I'll leave it to others to explain why the shrinking ice is more a cause of climate warming, than it is an effect.

jzk · 19-08-2008, 10:54

Gord,

Your images compare Sept 2007 (when the cap is small) to an average over several years. How is that a scientific comparison?

How about this one?

Mar 1979 and Mar 2008:

Daily Arctic Sea Ice Maps

Still slightly less ice, but not the picture your images paint.

But that brings up the real questions:

What is causing this?

Is this change "bad?"

Should we reverse the change?

Can we reverse the change?

Dave the Canuck · 19-08-2008, 11:32

If anyone gets a chance, pick up Bill Brysons' book, "A Short History of Nearly Everything". He spends some time on the cyclical nature of climate change and presents it in such a manner that even a complete idiot such as myself can understand. It's not pure science but a very worthwhile and interesting read. Humourous and also very sobering esp when you realize how insignificant we really are. Another great reason to chuck it all and go sailing as soon as you can.

If you're teetering on the edge of the cruise/no cruise decision. Read this book. You'll cruise.

TaoJones · 19-08-2008, 11:59

jzk, your comparison of images from March, 1979 and March, 2008 are interesting, but they don't show what you seem to think they show. The extensive areas in white are, in fact, Greenland, northern Canada, Alaska, Russia and northern Europe with a covering of snow, not ice. Purple represents ice at a much lower temperature than the white areas. If you advance the image on the right to yesterday, August 18, 2008, you will see that the white is, as one would expect, almost entirely gone, save for that covering Greenland which lies beneath hundreds of feet of ice.

http://igloo.atmos.uiuc.edu/cgi-bin/...&sd=18&sy=2008

Or, if you set the date on the left to March 18, 2008 and the one on the right to August 18, 2008, you can virtually melt all that snow.

http://igloo.atmos.uiuc.edu/cgi-bin/...&sd=18&sy=2008

More to the point, if you have some objection to Gord's comparison of a specific date to an average, set the dates to September 18, 1979 on the left image and to September 18, 2007 on the right. That will illustrate Gord's point that, at summer maximum, the sea ice cover has greatly diminished.

http://igloo.atmos.uiuc.edu/cgi-bin/...&sd=18&sy=2007

TaoJones

**GordMay** · 19-08-2008, 12:18

jzk asks, what he thinks are (but aren’t) “the real questions”:

Q. What is causing this?
A. MOSTLY HUMAN ACTIVITIES

Q. Is this change "bad?"
A. YES. Why would anyone want to exchange a know(mostly) benign climate, for an unknown (tho’ predictably bad) climate?

Q. Should we reverse the change?
A. YES. See above.

Q. Can we reverse the change?
A. I HOPE & EXPECT SO.

jzk · 19-08-2008, 12:48

Quote:

Originally Posted by TaoJones

jzk, your comparison of images from March, 1979 and March, 2008 are interesting, but they don't show what you seem to think they show... TaoJones

I thought about explaining that the white parts were snow cover, and only available in recent years, but since the website contains that information in bold on the bottom, I figured that everyone could just read it there!

Brent Swain · 19-08-2008, 13:36

A friend who cruised the Arctic recently with the Canadian coast guard said they went a long way north and couldn't find the sea ice.Just open ocean.
Brent

TaoJones · 19-08-2008, 14:03

Quote:

Originally Posted by jzk

I thought about explaining that the white parts were snow cover, and only available in recent years, but since the website contains that information in bold on the bottom, I figured that everyone could just read it there!

Since you found Gord's NASA image, evidently, not scientific, and offered images from March '79 and March '08 as somehow more scientific and contradictory to the NASA image, what exactly is it you were trying to prove? The examples you posted a link to are from the end of winter, while Gord's NASA image is from the end of summer - isn't that a bit of an apples and oranges thing, at best, and misleading at worst, since the March '08 image shows snow cover that the '79 image omits? And, leaving all that aside, don't you agree that the last image I provided a link to, comparing September '79 with September '07 proves Gord's point?

TaoJones

anotherT34C · 19-08-2008, 14:16

Quote:

Originally Posted by TaoJones

Since you found Gord's NASA image, evidently, not scientific, and offered images from March '79 and March '08 as somehow more scientific and contradictory to the NASA image, what exactly is it you were trying to prove? The examples you posted a link to are from the end of winter, while Gord's NASA image is from the end of summer - isn't that a bit of an apples and oranges thing, at best, and misleading at worst, since the March '08 image shows snow cover that the '79 image omits? And, leaving all that aside, don't you agree that the last image I provided a link to, comparing September '79 with September '07 proves Gord's point?

TaoJones

I think it's fair to criticize (jzk) an image labeld as a multi-year average compared to one labled Sept (the month of ice minima) as misleading. I'd like to know the source of those images. It's possible it was an average of successive septembers, but poorly labled.

However, when you compare apples to apples (sept 79 to sept 07, or mar 79 to mar 07) the point is clear. The ice is receeding, and receeding fast.

anotherT34C · 19-08-2008, 14:27

In fact, I'm pretty sure the image Gord posted was a combination of successive Septembers. If you were to include March (ice maxima) the ice extent would be much greater than what was shown in Gord's pic.

http://igloo.atmos.uiuc.edu/cgi-bin/...&sd=18&sy=1979

I think it was just a poorly labeled image.

This image fits;

http://igloo.atmos.uiuc.edu/cgi-bin/...&sd=18&sy=2007

Lightfin · 19-08-2008, 15:40

Seems I recall reading or hearing that the ANTARCTIC has been colder and growing more ice.

Is this true, and if so, why the opposite of the ARCTIC?????

Amgine · 19-08-2008, 15:47

In scientific circles there is no discussion regarding whether or not there is human-influenced climate change, or that it is (generically) harmful to stable weather patterns.

It's only in political/economic settings that there is dispute about whether or not it's happening. That is, the ignorant and under-informed, or those who are lying, willfully or otherwise.

So, there's really no point in trying to argue with people who refuse to accept evidence and reports from the people most informed on the subject.

Amgine · 19-08-2008, 15:57

Quote:

Originally Posted by Lightfin

Seems I recall reading or hearing that the ANTARCTIC has been colder and growing more ice.

Is this true, and if so, why the opposite of the ARCTIC?????

It isn't. As an example, the Wilkins ice shelf is disintegrating; a 160 sq miles melted just in one month.

Eleven · 20-08-2008, 00:55

There is surely no doubt that the current levels of fossil burning is not good. In terms of whats left for the next generation and what condition we leave the planet in.
The increase in huricane activity n the past few years is co-incidence, the floods of the last few years are con-incidence, etc etc.
The rise in sea levels is due to the rainfall, not the ice melt up north. Sorry, can't hear you, my head is stuck in the sand.
Turn off the air conditioning, put on warmer clothing. Use carbon when the temperatures are ten degrees centrigrade outside your comfort zone, not one. Drive a little slower, keep your car a little longer. Nothing drastic, just do a bit while we wait and see who's right.
Unfortunately the safest place might not be at sea if the weather turns nastier but on land is not so good either. Buy a chunk of real estate with altitude so when it gets hot you've got a cool place to go ( or sell ).