I have recently watched a film called the inconvenient truth by al gore and it is all about global warming and how the earth is suspected to change drastically within the next 5o years due to global warming. The film states that within the next 70 years or so the uk is likely to be in a iceage.and it is said to last up to 1000 years. This will happen by the north polls ice is melting drastically by the sun. this is not from the sun hitting the ice though this is caused by the sun hitting the water around the ice and heating it up. 90% of the suns rays just reflect off of the ice but as atmosphere aroun us is being thickend due to global warming 40% of the suns rays out ogf 90% is getting trapped.as the ice is melting less of the suns rays is reflecting off of the ice and is going into the atlantic ocian and is therefore warming up the ocian and is causing the ice to melt dramastically quicker than what was origonally suspected. the way that the ice age is suspected to happpen is that the tide of the ocien will stop going round in its normal cycle when the ice is compleatly gone and this will effect the cycle of whick the tide goes and will cause the iceage. urope will get a iceage becaus we are right by the cold tide and if that stops it will just freeze. when this happens aswell it is said that 45% of the earths land will be under water because when the ice melts this is causing more wather to be in the ocians and also it is said to rise at least 20 ft when the north poll ice melts. 
If you want any more information feel free to ask.

Yes, it is widely believed that global warming should ultimately make the UK a colder place due to the cessation of the Gulf Stream. This is not a tide though, it is part of what is called the Thermohaline conveyor (according to the Open University Oceanography course that I did about 4/5 years ago now) or in other words it is the main (cold) deep water currents and the corresponding (warm) upper water ones.
Melting of ice at the North Pole will make the surface waters far less saline and therefore less dense so they will not sink like they do at the moment (the start of the North Atlantic deep water current). This is what will lead to the end of the Gulf Stream coming our way and keeping us relatively warm despite our latitude.
The Gulf Stream has stopped before in previous glacial periods of this ice age, but I can't remember which book that I have that gives the details.

It's the melting of the Greenland Ice Sheet that will cause the main problems rather than the North Pole sea ice.

Yes, you are right, I said North Pole in a general 'up there' sort of way which is not very scientific is it! Next to Greenland is where the North Atlantic deep water sinks and starts it's journey.

Try the Hollywood film "The Day After Tomorrow" - vastly exagerrated (as most films), but the priciple's the same - melting ice cools the sea and stops the Gulf Stream, everywhere north of the Med freezes.

Melting ice might cool the sea, but that is not what will cause the Gulf Stream to stop, (well, at least not as I understand it though I am happy to be corrected.)

This is how I understood it. Currently, winds evaporate water in the Arctic which leaves more saline water at the surface. This is denser than the water below so it sinks through the water column. It then travels south along the thermohaline conveyor - which is a basic circulation pattern of deep and surface currents over the globe. The Gulf Stream is the surface current drawn in to replace the water that has sunk.

spikey said:

melting ice cools the sea and stops the Gulf Stream

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Maybe thats how the film portrays it but what I believe happens is: Large amounts of melting ice (fresh water) pouring into the North Atlantic where the Gulf Stream water usually sinks causes lower salinity and thus less dense water and so it doesn't sink which probably breaks the cycle of flow..

My high school geography is a distant memory, and I am not as well versed as others in the physics of the Gulf Stream, but as I stated, the film is vastly exagerrated and simplified. Apart from anything else, there probably wont be a great deal of the UK left, after the rise in sea level, and the  isostatic depression of the land due to the weight of ice.

Bring it on!....

spikey said:

My high school geography is a distant memory, and I am not as well versed as others in the physics of the Gulf Stream, but as I stated, the film is vastly exagerrated and simplified. Apart from anything else, there probably wont be a great deal of the UK left, after the rise in sea level, and the  isostatic depression of the land due to the weight of ice.

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If we are going to get isostatic adjustment due to the weight of ice on the UK then surely the sea level rise will not happen (assuming we are not the only ones covered in ice) because the ice will not have melted after all. Or at the very least it will have melted then reformed in other places.

Sorry, couldn't resist pointing that out!

If anyone wants some light reading.....

http://www.ipcc.ch/

I'm confused, should  Ibuy my fly-drive holiday home in France or Scotland then???  :-\

Yes I am confused, I thought we had just had the warmest year for
three hundred & fifty years and are on course for the warmest, wettest & windyest January ever & we were told that for us Global Warming would mean
Sun like Spain & wind & wet!
Stop confusing me.

I would assume that there's more water in the north Atlantic than it would take to cover the UK with ice, even given that there would be a large amount of sea ice, and I also thought that isostatic adjustment swung one way then the other (ie. higher sea level, before land lowering), before finding equilibrium. However, on reading previous posts, Anne has a degree in this, so she's probably got a great deal more in-depth knowledge.

My apologies if I have got things wrong.

No, you are right when you say that it takes time for everything to settle into an equilibrium. Isostatic adjustment is going to take the longest. I understand Scotland is still rebounding from the ice from the last glacial period at the rate of 1cm a year!

Also the thermohaline circulation thing takes ages to do a complete circuit - somewhere in the order of a thousand years or so - I wonder whether this would suddenly stop when the North Atlantic water stopped sinking, or whether its momentum would keep it going long enough to keep the Gulf Stream going for the rest of my life time at least!

Anyway, is the UK going to become one huge ice cap? or are we just going to have the same sort of winters that other countries at the same level of latitude as us have?

Sounds to me that those of us living down here near sea level are not going to do well out of this. We will be flooded out and freezing cold at the same time!

Good job I live in the Peak District - We'll just hve the hypothermia to deal with, whilst skiing across the ice from one unsubmerged peak to the next!!

We've got some good examples of isostasy down here in Cornwall - Fal and Tamar estuaries and a few others.  Don't know if they're still rebounding though we do get a few small earthquakes from time to time.

Hi Gus,

What has/is happening to those estuaries that is an example of isostacy? - Just interested to know!

Anne said:

What has/is happening to those estuaries that is an example of isostacy? - Just interested to know!

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As Scotland rises, the south coast sinks (as a piece of floating wood does when you remove a weight from one end), drowning the valleys and forming the estuaries.

I've recently read an in depth well-researched (over 10 years) study which argues coherently and convincingly that the world's population has already tipped the brink into major, rapid, catastrophic decline resulting in the loss of about 90% of the present world's population due to famine, disease, wars and collapse of manufacturing, distribution and economies. Given that dying is worse than sun burn, doesn't this take priority over global warming being of concern?

Ref: The Rapid Growth of Human Populations 1750 - 2000, by Dr William Stanton, Multi-Science Publishing, September 2003, ISBN 0 906 522 218