Ice age maps predict change in Australian climate

Sydney, Jan 20 (IANS) New maps of the earth’s surface during the peak of the last Ice Age points to northern Australia become wetter and southern Australia drier due to climate change in future. “During the last Ice Age - around 20,000 years ago - sea surface temperature was as much as 10 degrees colder than present and icebergs would have been regular visitors to the southern coastline of Australia,” Timothy Barrows of the Research School of Earth Sciences at Australian National University (ANC) said.

The temperature was estimated by measuring changes in abundance of tiny plankton fossils preserved on the sea floor, together with chemical analyses of the sediment itself.

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“One of our major findings was that the continent’s mid latitudes (Canberra, Perth, Adelaide, Melbourne and Sydney) are very sensitive and experience the greatest climate change in and out of Ice Ages. This is where we should focus monitoring and look at past impacts of climate change.”

The global warming at the end of the last Ice Age was the greatest in recent geological history. Temperatures warmed by as much as six to 10 degrees across Australia.

“We expect that the same pattern of change will hold for future global warming, with the temperate latitudes changing the most and the tropics changing the least,” Barrows said. “It should be wetter in the tropics and drier in the south as climate belts shift.

“Recently we have found that right at the end of the last Ice Age, temperatures were actually warmer than they are now in the southwest Pacific Ocean. We still do not know the reason for this.”

An international consortium of scientists from 11 countries has produced the maps, according to an ANU release.

The study is scheduled for publication in Nature Geoscience.