Nice work the NZ harold.

[TwoSeven]

If the poles melted, wouldnt you have a couple of puddles of molten alloy ?

[WRT]

If the ice melted the volume would be less. Water expands when it freezes.

Maybe, but it also floats. When it melts, all the bits above the waterline will now be back below the waterline . . .

Now I may be wrong here, but wouldn't the WEIGHT be the key? After all, something (anything) will float if it displaces more water than it weighs. Hence how concrete and steel ships can float.

So, does ice weigh more than water? Cant see that it would, so therefore, if the polar caps melt and all that ice turns to water, its still only going to weigh the same and the levels wont change much?

Hell, maybe I just talking gibberish. Be an interesting experiment. Fill a jug with a liter of water, freeze half of it, then dump the resulting ice cube back in the remainder of the water. See what level the water goes back up to . . .

[ManDownUnder]

That's terrible news,the Poles are the entrance into the interior of the Earth - you do know that the Earth is hollow don't you?

I'm worried because the earth's just a big balloon, and if the poles melt, the corks holding the air in will be gone, and we'll go fizzing off to a part of the galaxy where I don't have any friends!

[Jamezo]

Maybe, but it also floats. When it melts, all the bits above the waterline will now be back below the waterline . . .

Now I may be wrong here, but wouldn't the WEIGHT be the key? After all, something (anything) will float if it displaces more water than it weighs. Hence how concrete and steel ships can float.

So, does ice weigh more than water? Cant see that it would, so therefore, if the polar caps melt and all that ice turns to water, its still only going to weigh the same and the levels wont change much?

Hell, maybe I just talking gibberish. Be an interesting experiment. Fill a jug with a liter of water, freeze half of it, then dump the resulting ice cube back in the remainder of the water. See what level the water goes back up to . . .

pure ice is less dense than water. if you were to put an ice cube in a half-filled glass of water, and let it melt, the resulting water depth would be identical to that of the un-melted system (as the ice cube displaces EXACTLY its mass of water)

the problems are infinitely more complex than this. there is a huge web of factors that affect ice melt and the effects of it. for example, sheet ice reflects sunlight back into space, whereas it is absorbed into ocean water, warming the area further. there is also a very large mass of ice that is not currently displacing water, located on continental areas. if this were to melt, it would be a Very Bad Thing. there is evidence that suggests there are a number of 'tipping points' that we are approaching with regards to our climate system; basically, if they happen, they can't 'un-happen'. if continental ice sheets were to melt, there's no way they can just regenerate this side of 10,000 years.

but meh, it's all a moot point if we release the aliens that are hiding under the arctic.

[chris]

Now, I'm no expert, but aren't there many different types of ice? I was always under the impression that the ice currently being discussed varies greatly in its density depending on the depth at which it sits? Ice at 1km below the surface is infinitely purer and denser than that which sits a few feet below the surface due to the weight bearing down on it. It is compressed to a point where it contains no impurities or air bubbles? Therefore, the deeper the ice, the heavier it is?

[Skyryder]

As I understand it is the ice on land that is going to increase ocean levels. Some time ago therewas an interview with one of the scientists who had come back from the Antarctica. They had taken measurements from one of the ice shelves that showed that the shelf was slipping off the land. Don't recall how much movement that was measured but do recall that the shelf was the size of France. I have never head of any news item about this again.

Skyryder

[Posh Tourer :P]

I'm worried because the earth's just a big balloon, and if the poles melt, the corks holding the air in will be gone, and we'll go fizzing off to a part of the galaxy where I don't have any friends!

We will go fizzing off? I presume this is just a cryptic admission that you dont have any friends anyway, and fizzing off somewhere would just make you think about it?

[Posh Tourer :P]

there is evidence that suggests there are a number of 'tipping points' that we are approaching with regards to our climate system; basically, if they happen, they can't 'un-happen'.

They said that 30 years ago too...... Who knows? :spudwhat: Every ice age is preceded by a spike in average temp, and we havent had an ice age for a while......

[Posh Tourer :P]

As I understand it is the ice on land that is going to increase ocean levels.

Correct-ah. Then there is also the continental rebound to worry about, ie what happens when you take the weight of the ice off the land. North America rose 10m when the last ice shelf receded. That'd displace more water, although it might balance out the equation a bit in terms of land loss for those areas already uselessly wasting away under 1km of ice. We wont be any better off, but it is a comforting thought, no?

Re the ice shelf, sure it is melting off.... There is a (slow) build up of ice off the mountains isnt there? Glacier-type things happen.......

I presume it is still a matter of great scientific concern, but the newspapers are bored of it, and couldnt get any new pictures. Perhaps they could re-run the story with pictures of Arctic sea ice floating about instead???

[Posh Tourer :P]

Pack ice and Polar Bears says Arctic to me.

Penguins and black mountains says Antarctic to me.

Ever see the Far Side cartoon with the polar bear disguised as a penguin? He was apparently very embarrased when someone wrote in to point out that they lived 12,000-odd miles from each other

Cartoonists with a well developed respect for reality are the best type......

[Jantar]

Lets just use a bit of science here. This link http://vortex.nsstc.uah.edu/public/m.../tltglhmam_5.2 will take you to the actual global atmospheric temperatures as measured by NASA for the lower troposphere. That is the part of the atmosphere in contact with the earth's surface and imediately above.

This one http://www.ssec.wisc.edu/data/sst/latest_sst.gif is for the current sea surface temperature.

For the sea surface to warm up then the atmosphere most also warm at the same rate. From the atmoshperic record we can see that for the Northern Hemisphere the rate of temperature change is 0.122 C per decade. Ice can not melt to water untill it reaches 0 C.

Here http://www.john-daly.com/stations/bodo.gif is the temperature data for Bodo in Norway, just inside the arctic circle. Note that the temperature there during this latest period ,which is suposedly the hottest in earths history, is still at least 1 C cooler than in the 1930s.

Have a look at Danmarkshavn in Greenland, http://www.john-daly.com/stations/dmkshavn.gif You can see that it is not unusual for the ice to melt in summer but to be ice free all year round will require an increase in temperaure of 25 C. At current rates of change that may happen in a little over 2000 years, but somehow I think the natural cycles will have repeated themselves a few times by then.

[WINJA]

14 YEARS TO PAY BACK THE MEDICAL BILL , THATS OUTRAGEOUS