This man swam under the East Antarctic ice sheet to highlight the impact of climate change

It's been 200 years since Russian explorer Admiral Bellingshausen discovered Antarctica. It’s a frozen wilderness, and the East of the continent is the coldest place on Earth – but scientists say they are starting to see signs of ice loss even there.

To draw attention to this plight, endurance swimmer and climate campaigner Lewis Pugh undertook a 1 kilometre swim under one of the region’s glaciers.

Braving freezing waters and a windchill factor of -15°C, he explored a river running through an ice tunnel formed as a result of the glacier melting.

And the experience was eye-opening. “Antarctica is melting,” he says. “Everywhere I looked, there was water rushing off the ice sheet, carving long ravines deep into the ice sheet, or pooling into supraglacial lakes.”

“This place needs protecting,” he adds. “It needs protecting because all our futures depend on it.”

‘The Polar Bear’

Pugh is the only person to have undertaken long-distance swims in all the world’s oceans. At 50, he’s a veteran of many icy adventures, including swimming over the North Pole during a brief break in the sea ice, and crossing a lake that formed on a glacier on Mount Everest.

He was named one of the World Economic Forum’s Young Global Leaders and in 2013 was appointed as the United Nations’ Patron of the Oceans.

His ability to withstand extreme cold has earned him the nickname of "The Polar Bear".

Pugh’s East Antarctic swim is part of his campaign to secure a series of Marine Protected Areas around the continent. Antarctica already has one of these zones, in the Ross Sea, but Pugh wants all the seas around the continent to be designated protection areas in order to stem the effects of climate change.

He has already visited Moscow to mark the anniversary of Admiral Bellinghausen’s momentous discovery. And he plans to head to Beijing, London and Washington to persuade world leaders to increase protection for Antarctica.

Warning to the world

Since the early 1900s, glaciers around the world have been melting fast, as temperatures have risen due to global warming.

This melting causes sea levels to rise, which increases coastal erosion and creates more frequent and intense extreme weather events. Together, the Greenland and Antarctic ice sheets are the largest contributors to global sea level rises.

The East Antarctic, with ice sheets formed over millions of years and several kilometres thick in places, has long been considered the most stable part of the continent.

But researchers say that is changing, with glaciers starting to move more quickly, which could indicate widespread shifts in the region.

"What is very clear to us from the science is that we now need to create a network of marine protected areas around Antarctica,” says Pugh. “It's an amazing place."

The World Economic Forum’s Net Zero Challenge was launched during this year’s Annual Meeting in Davos, challenging nations and corporations to do more to achieve the targets set out in the 2015 Paris Agreement.