board77

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BTW, t0by, if an ice cube is sticking out of the water, then when it melts any part that isn't already under the water becomes water itself. Therefore the level of the water must rise if nothing's sticking out any more.

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Seriously though, don't refute climate change people- it's happening, and within living memory.

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Yes actually that is wrong, the ice cube sits in the water and displaces an amount equal to its total volume. when it melts that volume does not dissapear it runs off into the already present water, thus the water level stays the same.

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any ice that's sticking out of the water won't add to the volume of the water itself initially.

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Greenland's ice cap under threat

By Dr David Whitehouse
BBC News Online science editor



It could all go, say researchers
Greenland's ice sheet could disappear within the next 1,000 years if global warming continues at its present rate, a report in Nature magazine suggests.
Jonathan Gregory and colleagues from the University of Reading, UK, say their studies forecast an 8C increase in Greenland's temperature by 2350.

They believe that if the ice cap melts, global average sea level will rise by about 7m (23ft).

Even if global warming was halted the rise could be irreversible, they say.

Warming threshold

The researchers estimated that Greenland was likely to pass a threshold of warming beyond which the ice sheet - second in size to Antarctica - could not be sustained unless much greater reductions were made in emissions of greenhouse gases.

They found that over the next 350 years global warming was likely to pass the critical threshold in 34 out of 35 model calculations.

It's quite possible that Greenland is already making a slight contribution to global sea levels

Dr Jonathan Gregory, University of Reading
Greenland's average temperature only needs to increase by 3C to melt its ice sheet, but some of the modelling studies forecast a much higher rise by the year 2350.

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Although the current rate of sea level rise is as much as 2mm/yr, it is not known whether the present ice sheets are shrinking or growing. Each year, about 8 mm of water from the entire surface of the Earth’s oceans accumulates as snow on Greenland and Antarctica. The average ice accumulation on Greenland is about 26cm/yr and Antarctica about 16cm/yr (please note accumulation is in water amounts, or about 5 times greater in snowfall). We do not know, however, whether the amount of water returned to the oceans in icebergs and melt water runoff balances the snow accumulation to within + 25%. This large uncertainty exists because there is little direct information on ice sheet volume change.