How fast seas will rise by a projected two metres by the turn of the century remains a large mystery, according to new research into Antarctic ice loss.
And scientists say the next 30-50 years will be critical to future planning for ice loss and the subsequent rising ocean.
New research published in the Nature journal, led by Monash University researcher Dr Felicity McCormack, studied the predictability of Antarctic ice loss and its impact on projected rises and found it to be — unpredictable.
Based on reports from the Intergovernmental Panel on Climate Change (IPCC), a rise in global seas of more than two metres by 2100 cannot be ruled out due to the large-scale collapse of the Antarctic Ice Sheet.
A university statement says such a rise in seas would expose a quarter of all Australian residential properties to flooding, render most Pacific Island nations uninhabitable and displace hundreds of millions of people globally.
RISING SEAS
However, the rate of the rising sea from now to 2100 is very uncertain due largely to the difficulty of projecting Antarctic ice loss.
Under a worst-case scenario, the IPCC says that the rise from just ice lose could nearly double in 30 years.
But until now, there has been no robust estimate of Antarctica’s contribution to sea level rise over the next few decades.
The research was designed to identify how much Antarctica ice will be lost over the next 30-50 years and if it can be predicted reliably enough to give governments and nations time to respond.
Dr McCormack says Antarctic ice loss at present is strong, steady and predictable until about 2050 according to reliable estimates.
“Accurately predicting how much and how fast global sea levels will rise offers vital information for future coastal planning and government policy,” she says.
This predictability breaks down by 2100 when the physical loss of ice becomes increasingly likely. For example, ice resting on bedrock below sea level can enter a rapid retreat which, once triggered, is difficult to reverse and could drive ice loss far beyond what climate change projections would suggest.
