Ice could hold clue to greenhouse effect

Media Release
February 10, 2009

Ice could hold clue to greenhouse effect

It wasn’t always quite so cold at the north and south poles. Between 40 and 65 million years ago in the early Paleogene period, there were no permanent ice sheets at the poles and water temperatures were about 10–20 degrees warmer than today.

Waikato University Masters student Ben Andrew says during this time there was a cold spurt of about two million years, and with it the ice grew and that led to the invigoration of ocean currents.

Andrew is part of a team involving Waikato, Otago and Victoria universities and Geological -and Nuclear Sciences (GNS) looking at this climate changing event that took place 58 million years ago. “Just what happened then could help us to predict the effects climate change will have in the future,” says Andrew.

With colleagues from Otago, Ben will be travelling to subantarctic Campbell Island this month to continue his research.

The project is called Ice in the Greenhouse and is funded by a Marsden Grant. Scientists from the different universities and GNS are looking at various aspects of the sedimentary rocks from that period, the fossils found in them, and how the ice growth influenced ocean circulation.

“We’re pretty sure the event was caused by a drop in carbon dioxide in the atmosphere. We’re trying to find out the effects of this event on global climate and ocean circulation. My particular interest lies in the record of erosion contained within New Zealand’s rocks caused by deep cold currents from Antarctica at the time.”

Andrew will board the Otago University research vessel Pelorus this weekend, travelling first to Bluff where DoC will check their gear to make sure they’re not going to take anything unwanted onto the island. They’ll spend almost a month on the island, sleeping mostly on the boat, but have got special permission to spend some nights onshore in a tent.

“It’s a great project to be involved with,” says Ben Andrew. “It’s good science, and it shows the benefits of collaborative research, where everyone is bringing different skills and knowledge and putting it towards what should be a useful result.”

ENDS

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