According to scientists, the West Antarctic Ice Sheet contains enough ice to cause a rise of between three to four metres in global sea levels, inundating heavily populated coastlines.
In the worst case scenario, this could occur over just a few centuries.
Peter Convey is tracking the changes in Robert Island, just off the Antarctic peninsula’s coast, for the British Antarctic Survey.
“97 per cent of the Antarctic peninsula is still covered by ice, so it’s not that it is all melting and and it’s just going to go away like that. But a small amount of the ice melting is enough to make a significant contribution to the water going into the ocean which makes a significant contribution to sea level rise,” he says.
At Robert Island, the ice retreat is observable on a small scale. Chilean plant biologist Angelica Casanova can’t help but notice the difference on the island, which she has been visiting for twenty years. Increasingly, plants are taking root in the earth and stone deposited by retreating glaciers – an early warning signal of what’s to come she says.
“As we know Antarctica has been the place that has registered the biggest increases in temperature – a rise of approximately 3 degrees in the last 50 years. We believe that these plants are true indicators of climate change and above all of global warming because they accurately illustrate change,” she says.
A few years back, scientists figured Antarctica as a whole was in balance, neither gaining nor losing ice. Now, two different studies use the words “irreversible” http://www.worldbank.org/depweb/english/beyond/global/chapter14.html and “unstoppable”.
It’s not the temperature of the water around Antarctica that has risen, but climate change has modified wind patterns pushing warmer water below the western ice sheet.
If nothing is done, the World Bank is warning of devastating flood damage to major coastal cities like Guangzhou, New York or Mumbai.