Threefold increase in Antarctic ice melting recorded

Global warming has contributed to a threefold increase in Antarctic ice melting over the last five years, with sea levels rising faster today than at any time since 1993.

A study led by researchers at the University of Leeds has found that the continent lost 219 billion tonnes of ice each year between 2012 and 2017, compared with a steady rate of 76 billion prior to that.

This has seen global sea levels rise from 2mm a year to 6mm since 2012, while a separate study from the Grantham Institute warns of a possible 25cm rise by 2070 without action to limit global warming.

Under a worst-case scenario of high greenhouse gas emissions, it is thought that ice melting could lead to a collapse of the entire West Antarctic Ice Sheet, with sea levels rising by approximately 3.5 metres.

The researchers warn that some of the changes facing Antarctica are already irreversible, and that decisions made over the next decade will determine the future of the continent’s ecosystem.

“This will rely on governments recognising that Antarctica is intimately coupled to the rest of the Earth system, and damage there will cause problems everywhere,” professor Martin Siegert from the Grantham Institute, said.

Antarctica stores enough frozen water to raise global sea level by 58 metres, and knowing how much ice it is losing is thought to be key to understanding the impacts of climate change.

In the worst-case scenario forecast by Siegert’s study, Antarctica will undergo rapid change, with warming, sea ice retreat and ocean acidification all altering marine ecosystems.

However, under a low-emission and strict regulations scenario, Antarctica is forecast to look much like it did in the early decades of the century, with slowing loss of ice reducing the threat of sea level rises.

“To avoid the worst impacts, we will need strong international cooperation and effective regulation backed by rigorous science,” Siegert said.

“If we recognise the importance of Antarctica, then there is the potential to enact changes that avoid ‘tipping points’ that cause runaway change, such as the collapse of the West Antarctic Ice Sheet.”

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