Open Eye: Testing the water in Antarctica

This summer's Arctic heatwave has been blamed on global warming. But on the opposite side of the world, the impact of climate change could be equally serious. Debbie Dixon reports

Dr Mark Brandon is a senior lecturer in environmental science in the Earth Sciences department of The Open University. For 12 years he has been making regular trips with the British Antarctic Survey, carrying out environmental research in the coldest place on earth. A key part of his current work is to examine the condition of the Antarctic ice shelves.

He explains: "Antarctica plays an important role in influencing the world's climate and weather because the ice reflects back the sun's energy. We know a lot about the thickness of Arctic sea ice, as nuclear-missile submarines have been going under it for years making measurements. But we know hardly anything statistically about the thickness of the Antarctic sea ice. It is a huge unknown."

The ice shelves are enormously important to the world's climate. They are the floating edges of the ice sheets that fringe Greenland and Antarctica. They contain 77 per cent of the world's fresh water, 99 per cent of all glacial ice and 10 per cent of the Earth's land area. If the ice sheets were to melt entirely, world sea levels could rise by up to 80 metres, seriously affecting up to 180 countries including China, India, Bangladesh, Vietnam, parts of the United States, Japan and the Netherlands. As many as 643 million people – 10 per cent of the world's population – could be displaced.

And there is evidence that melting is occurring in Antarctica. In 2002 the big Larsen B ice shelf collapsed within the space of a month, an event which Antarctic researchers have attributed to climate change. Researchers are now looking at the Wilkins and the King George VI ice shelves which, they believe, will be the next ones to go.

"We need to find out how much they are melting now," says Brandon. "One thing we can be certain of is that atmospheric temperatures are going to continue to rise over the next 50 to 100 years, whatever we do. After the Larsen B ice shelf collapsed, the satellites showed us that all the glaciers that previously fed into that ice shelf suddenly speeded up, a bit like taking a cork out of a bottle. That is adding to the sea-level rise."

The research is timely because the extent of world sea level rise likely to be caused by climate change is subject to debate. A report by the Intergovernmental Panel on Climate Change (IPCC), published earlier this year, estimated that sea level rises up to 2100 could be in the range of 18 to 59cm, less than previously thought. But Brandon warns these figures do not take into account the contribution of ice in Greenland and Antarctica melting. "This could easily add 10 to 20cm to the prediction, and it could be a lot more.

"I can see why the IPCC has ignored the data on ice shelves. We don't know much about them and the IPCC wanted to be as accurate as possible, because the more precise you can be, the more you can tie down countries that might deny there is an issue."

Brandon and his team see their research as vital to enable the IPCC to take ice shelves seriously. "We know from satellite data that this is an important region, but nobody has done this kind of research before."

The work, carried out in temperatures around -20C, involves making very precise measurements of the temperature and salinity of water flowing under ice shelves. Scientists work from onboard an icebreaker, the British Antarctic Survey's Royal Research Ship James Clark Ross, using high-tech and highly expensive instruments.

"In 2001 we carried out the first large-scale measurements of the thickness of Antarctic sea ice by using an autosub, an underwater robot which is able to survey remote environments. We were fantastically successful and got some high-profile science out of it," says Brandon. In particular, Brandon and his colleagues were able to get the first serious estimates of krill, the minute creatures which are food, directly or indirectly, for the abundant wildlife in the Antarctic seas. However attempts to use the autosub under the ice shelves were unsuccessful. So this year researchers have been using a different technique, lowering a piece of sensing equipment at the edge of the ice shelves down towards the seabed.

"This year we managed to measure all sides of the ice shelf we think is closest to collapse – the Wilkins. We know what water is flowing in and out of the cavity beneath the floating ice, and because we know the salinity, we can use conservation equations to infer how much of the bottom of the ice sheet is melting." Their results will be published next year.

As well as making their research available to the scientific community, Brandon has been reaching new audiences with his Antarctic blog, which attracted more than 100,000 hits (see below).

"A lot of academic research is hidden, and, for the first time, we were able to show our work," he says. "We always need to raise the profile of our research and this was a great way to do that. It was also the first time that my mum actually got to see what I do. In addition, I was in contact with junior schools in Essex explaining to the children about Antarctica and what I am doing."

As the world's only continent with no permanent inhabitants, Antarctica is governed by an international treaty system which protects its environment and explicitly promotes peaceful international co-operation in scientific research. During the summer, when most of the research takes place, it is home to as many as 4,000 scientists and support staff. Increasingly though, the scientists are not alone.

Growing numbers of tourists are choosing to spend £4,000 to make the day-and-a-half trip to the Antarctic Peninsula from Ushuaia in Argentina. Brandon himself has worked as a lecturer, boat driver and shore guide on a tourist ship. He is not unduly concerned about the environmental impact. "The tourists only visit a small area as most of the Antarctic is covered in ice. On average up to 15,000 tourists visit half-a-dozen sites each year. They think they are all getting a unique experience visiting untouched places when the truth of it is that they all come back with the same pictures."

Nevertheless the presence of tourists in what has been described as the world's last great wilderness can jar, he admits. "Once I was steering a passenger-filled boat through icebergs. It was so beautiful I stopped the engine to take in the atmosphere. All you could hear were penguins and camera shutters. Then an excited passenger cried out: 'Oh my God, it's just like Disneyland.' I bit my tongue, restarted the engine and carried on."

Mark Brandon is a contributor to the OU courses U316 The Environmental Web, S216 Environmental Science, U216 Environment and is working on a new first level environmental course. His Antarctic blog can be found at: www.open2.net/blogs/antarctic. More information about Antarctic research and the British Antarctic Survey can be found at www.antarctica.ac.uk

Extracts from Dr Mark Brandon's Antarctic blog:

16 March 2007

"Being on a ship breaking ice is a very unusual experience even to experienced sailors. Instead of a gentle roll as the ship makes way, there are constant judders, jerks and crashes...It is strange, and beautiful, but no-one could call it relaxing."

30 March 2007

"All the time the ship is being bashed around by the sea ice. It's OK work when the sun is out, and it's the middle of the day, but as I type this, it's dark again and we are in ice that's almost 4 m thick and being menaced by a couple of icebergs that can't decide which direction to drift in."

3 April 2007

"To get on in this environment, you need to be exceptionally relaxed and very calm. Now forty or so people with relaxed attitudes doesn't make for good exciting Big Brother-type television. We don't argue, shout at each other or anything like that, we just go and get the job done."