Research from drilling suggests that the
West Antarctic ice sheet will melt first,
along with Greenland.
Image: iStockphoto

Tim Naish says new evidence shows that changes to Antarctica’s most vulnerable element, the West Antarctic ice sheet, could raise global sea levels by up to five metres.

The Director of Victoria University's Antarctic Research Centre will present this new evidence at his inaugural professorial lecture tomorrow night at Victoria University.

"Polar ice sheets have grown and collapsed at least 40 times over the past five million years, causing major sea-level fluctuations. The most recent 'interglacial' has lasted 10 000 years, during which time global sea-level and atmospheric temperatures have remained more or less constant, and human civilisation has flourished."

Professor Naish says much of his research has focused on the international ANDRILL drilling programme in the sedimentary layers of the West Antarctic ice sheet.

"Evidence shows that this sheet is expected to melt first, along with Greenland. West Antarctica sits below sea level, so as the ocean warms, the ice sheet also warms. One way to understand this is to use the paeloclimate record to go back to a time when the earth was warmer and to see how West Antarctica behaved. We know that greenhouse gases in the atmosphere were slightly above what they are now, and the earth was two to three degrees warmer. When the West Antarctica ice sheet collapsed numerous times, it raised sea levels by up to 10 metres."

Professor Naish says his lecture will focus on this major finding, and its relevance to future climate change.

"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."

The findings are an opportunity to take a major step forward in our understanding of the Antarctic ice sheet’s response to global climate change.

Professor Naish became Associate Professor and Deputy Director of Victoria's Antarctic Research Centre in 2005 and was promoted to Director of the Centre in 2007.

For the past five years he has led four major paleoclimate research initiatives including the international ANDRILL drilling programme.