Isaac Davison

Isaac Davison is a NZ Herald political reporter.

Antarctic key to tackling climate issues

As the PM heads to South Pole this week, Isaac Davison looks at why the continent holds the key to climate change

Antarctic Research Centre director Tim Naish with the drill rig that pierced the Ross Ice Shelf. Photo / NZ Herald
Antarctic Research Centre director Tim Naish with the drill rig that pierced the Ross Ice Shelf. Photo / NZ Herald

Antarctica is "ground zero" for global warming, climate scientists say, and New Zealand will be the first to feel the effect of its melting ice.

As the world warms, researchers' eyes are turning to the frozen continent, where trillions of tonnes of water is contained in the ice.

New Zealand scientists say gradual ice melt at Antarctica will transform the world, altering everything from coastlines to the frequency of storms.

Prime Minister John Key will inspect some of the New Zealand-led science projects after arriving in Antarctica early this morning.

He will be briefed on the Antarctic Research Institute's activities before travelling to one of the premiere science spots in the Dry Valleys tomorrow.

Gateway Antarctic director Brian Storey, from the University of Canterbury, said that as one of Antarctica's closest neighbours, New Zealand had a particular interest in the climate-related changes in Antarctica.

"What happens in Antarctica really influences the rest of the world - just simply the amount of water that's locked up in the ice and the 60m or 70m of sea-level change that could resolve from a warming Antarctica.
"Of course, New Zealand is directly in the firing line. This is totally relevant to the Christchurch rebuild and whether we should be rebuilding close to the sea."

Antarctic Research Centre director Tim Naish, based at Victoria University, said it had already been determined that human-influenced climate change would melt Greenland and the West Antarctic ice sheet. It was now up to researchers to work out how many centuries it would take.

A Victoria University-led team of scientists finished drilling through nearly 800m of ice on Roosevelt Island in the Ross Sea before Christmas. The ice core that was created was expected to help produce a highly detailed climate record of the past 40,000 years.

Professor Naish said: "When you drill through these layers of snow, it's like turning the pages of a history book, each layer is going further back in time."

The scientists would extract air bubbles from each layer, which would reveal the temperature and amount of carbon dioxide in the air in each previous year.

"It should give us a really good record of the Ross Sea region coming out of the last ice age.
"That'll be really useful for telling us what we might be in for as the climate continues to warm," Professor Naish said.

A similar study that he led found that when the earth last had similar levels of CO2 to the present day (three million years ago), the air temperature was 2 to 3C warmer.

One of the great unsolved questions in climate change science was how the melting polar ice caps would affect global sea level rise.

The Intergovernmental Panel on Climate Change has predicted sea levels would climb 1m this century. But that estimate did not take into account polar ice melt.
University of Canterbury scientists were monitoring the rate of sea ice retreat at Antarctica by satellite and by observing the speed that ice was moving in glaciers or streams.

Professor Storey said the group came up against one confounding factor. While ice was melting dramatically at the Arctic, the ice sheets at the East Antarctic were thickening.
"In fact, this past year there was the biggest extent of sea ice ever," he said.
The phenomenon appeared to be the result of the ozone hole over the continent, which had cooled the upper atmosphere by 2 to 6C. Despite this growth in sea ice on the eastern side, the West Antarctic ice sheet was still shrinking.


Kiwi-led climate science projects
Fish: University of Canterbury scientists are investigating how Antarctic fish will fare in warming waters. The fish were removed from their habitat, placed in warmer water and their oxygen intake, heart function and exercise ability measured.

Drilling: A Victoria University-led group of scientists have drilled through 760m of ice and planned to create a climate record of more than 20,000 years by extracting information such as historic carbon dioxide levels from the compacted layers of snow. The study will help researchers understand how greenhouse gas emissions could affect climate in the Ross Sea.

Ice: University of Canterbury researchers are using satellite images and GPS to measure whether East Antarctic ice sheets are melting/growing because of climate change. Glacier movement and surface images had determined the ice was thickening, but this was believed to be caused by cooling as a result of the ozone hole over the continent.

- NZ Herald

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