Socialist Worker

Antarctic melt poses grim threat

by Dave Sewell
Issue No. 2518

The lakes on top of the Langhovde glacier

The lakes on top of the Langhovde glacier


As the Antarctic winter draws to a close, scientists watching the continent’s ice shelf have found alarming signs that it could be falling apart.

The Antarctic ice cap contains 90 percent of the world’s ice. The question of what happens to it could be one of the most important for humanity’s future over the next few centuries.

If it melts, sea levels would rise by up to 60 metres which would threaten London and most coastal cities. And the signs don’t look good.

A satellite-based study of the Langhovde Glacier in East Antarctica found nearly 8,000 striking blue lakes have formed on its white surface since 2000.

They show that ice is melting at the top of the glacier, apparently due to rising air temperatures.

The fastest period of lake formation was in the summer of 2012-13, when temperatures rose above freezing point on 37 days.

Worse still, they appear to be draining into the depths of the glacier.

Breaking

Bringing water down into a glacier’s core is key to breaking it apart. The lakes are new to the region, but similar to meltwater lakes found in Greenland—where a much smaller icecap is already melting fast. East Antarctica had been thought to be mostly stable.

If this happens on as large a scale as in Greenland, scientists should expect to see “meltwater plumes” of water carrying sediments into the sea around the ice shelf. So far they haven’t.

Glaciologist Stewart Jamieson, one of the study’s authors, said the lakes “are probably not big enough to do much at present, but if climate warming continues in the future, we can only expect the size and number of these lakes to increase.”

But the authors stressed that they chose Langhovde not because it’s special, but simply because there is more data for it. What is happening there is likely to be happening all over East Antarctica.

Greenland-style meltwater drainage is believed to have been part of what caused the spectacular break-up of the Larsen B ice shelf in 2002.

Then the US National Snow and Ice Data Center said the Earth had lost a major feature that had “likely existed since the end of the last major glaciation 12,000 years ago.”

Developing

Now another study has found that event could be repeating. A huge crack is developing in the Larsen C ice shelf.

It’s Antarctica’s fourth largest ice shelf—ice spread 350 metres thick over an area almost as big as Scotland.

The British Antarctic Survey’s project Midas found this month that it had reached a length of 80 milies—14 miles longer than when they last saw it in March before the Antarctic winter.

Since last year it has widened from 200 metres to 350 metres.The researchers warn that 2,316 square miles of ice could soon break away and melt.

That could mean the whole Larsen C ice shelf follows Larsen B into destruction.

The pressure on the ice is only going to grow. Every single month this year has broken temperature records. Earth was hotter in July than in any month in the past 100,000 years.

We need urgent action to prepare for the mounting climate chaos and to bring down the greenhouse emissions fuelling it.

Fighting the capitalist class who keep increasing them is a matter of life or death.


If you enjoy Socialist Worker, please consider giving to our annual appeal to make sure we can maintain and develop our online and print versions of Socialist Worker. Go here for details and to donate.

Mobile users! Don't forget to add Socialist Worker to your home screen.