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Antarctic melt - sea could rise 5m
Last updated 12:58 02/07/2009
Sea levels could rise by up to five metres because of a melting Antarctica ice sheet, says Professor Tim Naish, director of the Antarctic Research Centre at Victoria University.
He said Antarctica's most vulnerable element, the West Antarctic ice sheet, presented a huge issue for civilisation.
Polar ice sheets had grown and collapsed at least 40 times over the past five million years, causing major sea-level fluctuations, he said.
The most recent "interglacial" had lasted 10,000 years, with relatively constant global sealevel and atmospheric temperatures allowing human civilisation to flourish.
Evidence shows the West Antarctic ice sheet was expected to melt first, along with Greenland.
"West Antarctica sits below sea level, so as the ocean warms, the ice sheet also warms."
Prof Naish said the earth in past ages had greenhouse gases slightly above today's levels and was two to three degrees warmer.
"When the West Antarctica ice sheet collapsed numerous times, it raised sea levels by up to 10 metres.
"In the past, these climate changes were happening naturally but now we've accelerated this process, the greenhouse gases are rising and temperatures are rising faster than they ever have in the past.
"It's one of the big issues of our time and it will have a profound effect on our future society."
Much of his research focused on the international Andrill drilling programme in the sedimentary layers of the West Antarctic ice sheet.
Scientists have in the past said a lot of Antarctic ice looks set to melt over the next 100 years, with the entire West Antarctic sheet likely to melt within 1000 years.
Victoria University vice-chancellor Professor Pat Walsh said Prof Naish's research had raised international awareness about the role of Antarctic ice sheets in climate and sea-level change.
Prof Naish will present his evidence of global warming at a lecture at Victoria University next Tuesday.
- NZPA
Last updated 12:58 02/07/2009
Sea levels could rise by up to five metres because of a melting Antarctica ice sheet, says Professor Tim Naish, director of the Antarctic Research Centre at Victoria University.
He said Antarctica's most vulnerable element, the West Antarctic ice sheet, presented a huge issue for civilisation.
Polar ice sheets had grown and collapsed at least 40 times over the past five million years, causing major sea-level fluctuations, he said.
The most recent "interglacial" had lasted 10,000 years, with relatively constant global sealevel and atmospheric temperatures allowing human civilisation to flourish.
Evidence shows the West Antarctic ice sheet was expected to melt first, along with Greenland.
"West Antarctica sits below sea level, so as the ocean warms, the ice sheet also warms."
Prof Naish said the earth in past ages had greenhouse gases slightly above today's levels and was two to three degrees warmer.
"When the West Antarctica ice sheet collapsed numerous times, it raised sea levels by up to 10 metres.
"In the past, these climate changes were happening naturally but now we've accelerated this process, the greenhouse gases are rising and temperatures are rising faster than they ever have in the past.
"It's one of the big issues of our time and it will have a profound effect on our future society."
Much of his research focused on the international Andrill drilling programme in the sedimentary layers of the West Antarctic ice sheet.
Scientists have in the past said a lot of Antarctic ice looks set to melt over the next 100 years, with the entire West Antarctic sheet likely to melt within 1000 years.
Victoria University vice-chancellor Professor Pat Walsh said Prof Naish's research had raised international awareness about the role of Antarctic ice sheets in climate and sea-level change.
Prof Naish will present his evidence of global warming at a lecture at Victoria University next Tuesday.
- NZPA
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