Under the ice

What does the latest research predict about the future for Antarctica? Amanda Cox reports.

When ANU researcher Dr Adele Morrison starts talking about deep-water ocean currents, I am intrigued, and then shocked, by a seemingly innocuous detail – her scale for referencing sea level rise is not centimetres but metres.

The last Intergovernmental Panel on Climate Change (IPCC) Report in 2013 was estimating around half a metre to a metre of sea level rise by the end of the century.

“More recent reports have suggested that that is a conservative estimate and it could actually be up to two metres by the end of the century,” she says.

As I contemplate what metres – plural – will mean for my favourite Batemans Bay fish and chip shop, Morrison explains that to predict how coastlines will change globally, we need to start by looking at the coastline of Antarctica.

“Hundreds of years into the future, Antarctica is the big uncertainty – we don’t know how much of it is going to melt.”

Antarctica’s glaciers slowly flow from the land down to the ocean. When they reach the ocean, they float as ice shelves within recesses along the coastline. The ice shelves are buttressed on the sides and ‘act like a cork, holding the rest of the land ice back’.