Professor David Walton of the British Antarctic Survey tells us that what happens in Antarctica affects us all

September 20th, 2010 by Richard Lord

Pat Costen, President of La Société Guernesiaise, introduced Professor, Emiterus Fellow David Walton of the British Antarctic Survey, who has made twenty-two visits to Antarctica.  Mrs. Costen thanked HSBC for sponsoring Professor Walton’s presentation.

Professor Walton began his presentation on Antarctica by telling the audience that climate change affects us all.  “The world is an interconnected place,” he said.  “What happens in Antarctica affects Guernsey.”

Professor David Walton told the audience that the whole world is interconnected and what goes on in Antarctica affects us in Guernsey (click image to expand)

Antarctica is a place of superlatives.  It has the world’s largest ice sheet and contains 65% of all the world’s freshwater.  The lowest temperature of -89.6 degrees Celsius has been recorded at the Vostok Station.  It is also one of the driest places on earth.  The dry valleys discovered by Robert Scott receives very little snow and the snow that is received sublimates.

Antarctica has some of the windiest places on earth with 300 days of gales per year.  During the summer the continent has an area of 14.2 million square kilometers.  In the Southern Hemisphere winter this area increases by 20 million square kilometers.  The whiteness of the continent affects the heat balance on earth.  Only 0.4% of the continent is free of ice.  The continent is covered by an ice sheet four kilometers thick.  The weight of ice depresses the rock lying underneath.  Only the tops of mountain peaks show through the ice sheet.

Research in the late 1960s and early 1970s showed many lakes under the Antarctic ice sheet.  More than 145 have been discovered.  The largest of these lakes is Lake Vostok, which is similar in size to Lake Ontario.   Lake Vostok has an average depth of 500 metres.  Professor Walton said that in the summer of 2011 the Russians would sample water from the lake for the first time that hadn’t been exposed to the atmosphere for half a million years.  The British are going to be drilling into Lake Ellsworth.

Geothermal heat from the earth’s crust, and massive pressure of the weight of the ice sheet allows the lakes to remain liquid.  Originally scientists thought that the Antarctica ice sheet sits on rock but they know now that there is a layer of water between the Antarctic ice sheet and the bedrock underneath.  This water acts as a lubricant to allow the ice sheet to move over the bedrock surface.

Antarctica wasn’t always snow covered.  Hundreds of millions of years ago Antarctica was a part of a supercontinent called Gondwana, which was made up of South America, Africa, Arabia, India, and Australia.  During this time dinosaurs roamed the continent and there were forests.

Many countries have claims on Antarctica but these claims have been put aside.  Antarctica represents international collaboration at its best.  The Antarctica Treaty of 1959 has 46 national signatories.  Twenty-eight of these nations do research in Antarctica and these represent the consultative parties that decide how Antarctica is governed.  These nations represent 65% of the world’s population.

Fishing in the Southern Ocean around Antarctica began in the 1970s with the arrival of the Soviet fleet and boats from Poland and other Eastern block countries, Professor Walton said.  It is now a world fishery that is closely monitored.  He said that stern trawlers and long-liners fish for squid, fish and krill.  About 400,000 tonnes of krill are harvested per year.  The prize fish is the Patagonian toothfish, Dissostichus eleginoides. Professor Walton admitted eating Patagonian toothfish and said it was tasty.  These fish live to the age of 50.  They can reach a length of two metres but grow slowly.  They are vulnerable to overfishing.

Professor Walton said that Antarctic fisheries is managed with an ecosystem approach but there is a large by-catch of commercially undesirable species that is killed and thrown back to the sea.  Unregulated pirate fishing in the Southern Oceans is fronted by Dutch, Spanish and Chilean companies.

Patagonian toothfish, Dissostichus eleginoides ©RLLord (click image to expand)

Professor Walton said that biodiversity of benthic organisms in the Antarctic was very high.  He compared the biodiversity to tropical coral reefs. There are gardens of cold water corals.

The British Antarctic Survey use Southern Elephant Seals to record oceanographic conditions in the Southern Ocean.  The BAS fit oceanographic equipment on the seals, which record temperature, conductivity, depth and other measurements.  The BAS has acquired hundreds of Southern Elephant seal transects.  These marine mammals dive to 1000 metres and travel great distances.  One Southern Elephant seal was traced from South Georgia to the Antarctic Peninsula.  Professor Walton said that this was a cheap way of acquiring detailed oceanographic data.

Professor Walton spoke of the Wandering Albatross, which is the largest marine bird.  These birds mate for life.  They breed every two years with their partner.  They are long-lived but they are dying out because of the long-line fishery and because of plastic pollution.  Professor Walton said that all marine birds around Antarctica are in decline.  The Wandering Albatross circumnavigates the Antarctic continent and migrates also along the coast of Africa and South America.  These birds dive into the sea for food.  They mistake plastic bags and polyurethane pieces for food.  As these materials are indigestible they accumulate in the bird’s stomach until the bird can eat no more and dies of starvation.

There are very few native fully terrestrial species in Antarctica.  Professor Walton illustrated this with an image of a arthropod from Antarctica.  It had a length of about 2 mm.  Arthropods are the only native Antarctic terrestrial species that can survive ice maxima.  These species are studied for their low temperature physiology.

Alien species introductions to Antarctica are of concern as there are potential habitat niches for invading species.

Professor Walton spoke about endolithic species – species living within stone.  He showed an image of sandstone containing layers of fungi and algae, and fungi and algae living symbiotically.  These species cannot survive outside rock.  They grow slowly, so slowly, that some species may grow for only five hours in a whole year.  These endolithic species may live for half a million years or more.

Scientists in Antarctic study the southern lights or Aurora Australis.  The Aurora results from the interaction of the solar wind with the Earth’s magnetic field.  Professor Walton emphasised the importance of studying the solar wind, using SuperDARN radar, because of its ability to interfere with man-made satellites.  He spoke of humanity’s dependence on satellites for telecommunications, remote sensing, land-management, GPS navigation, and entertainment.  Antarctica is also used as a base to study astronomy as the atmosphere is clear, cold and thin due to the elevation of the Antarctic plateau.

He said that the British Antarctic Survey employs 450 people and has a budget of £47 million.

Professor Walton spoke about the Antarctic’s role in studying climate change and sea level rise.  There has been a distinct warming trend since the 1880s.

The Antarctic Peninsula has recorded the greatest increase in temperature compared to the rest of the Antarctic continent.  Glacial speed into the sea has increased by 12 percent. Major discharges into the sea are at Pine Island, Thwaites and Smith glacier. Pritchard and Vaughan of the BAS measured flow rates of 300 glaciers.  They found widespread acceleration of glaciers on the Antarctic Peninsula.

The  melting of the west Antarctic ice sheet and the Greenland ice sheet is the largest contributor to sea level rise followed by ocean warming and thermal expansion of the sea.  The contribution to sea level rise of thermal expansion of the upper 700 metres of ocean is accelerating. Of all the contributions to sea level rise this is increasing the fastest.

Glaciers are melting around the world but their contribution to rising sea level is negligible.  Their main importance is as a source of drinking water – particularly the Himalayan glaciers providing melt water to feed the rivers of South-East Asia.

The melting of the west Antarctic ice sheet is of concern because it could contribute to a rise in sea level of 1.5 metres.  It is warming the most with an average increase in temperature over the last few decades of 0.25 degrees Celsius.  Professor Walton said that the East Antarctic ice sheet was very cold and wouldn’t melt for thousands of years.

Professor Walton spoke about the Thames Barrier is on land on that is subsiding.  In 1985 the Thames barrier closed twice to keep high tides out of the London area.  In 2009 it had to close ten times.   The sea level has risen on average by 20 cm between 1880 and 2000.  The Newlyn, Cornwall tidal gauge shows the sea level rising by 1.71 mm per year; in Brest, Brittany the sea level is rising by 1.0 mm per year.  The sea level around Guernsey could rise by between 10 cm and 90 cm by 2080.

Antarctica plays a major role in Thermohaline circulation.  The Antarctic deep water formation is fundamental to driving the Gulf Stream, which keeps Northern Europe warmer than it would otherwise be.  The Thermohaline circulation moves energy and nutrients around the globe.  The Southern Ocean C02 sink has weakened between 1981 and 2004 by 0.03 thousand million (billion) tonnes of carbon (gigatonnes)/y per decade.

Another major concern is ocean acidification. C02 dissolved in seawater produces carbonic acid.  A more acidic ocean interferes with the development of animals that require carbonates for building skeletons and shells.

In summary, Professor Walton said that scientific understanding is running ahead of economic modeling.  Humans are not thinking strategically because of the timescales involved.

“We want the world to stay the same because we like our quality of life but if we stay the same the world around us will not.” “And we cannot rely on quick fixes.  We don’t have an engineering solution to tackling climate change,” Professor Walton said.

However “the elephant in the room is world population.  There are too many of us.  Our population is now approaching 7 billion and is expected to rise to 9 billion.  The human population exceeds the carrying capacity of the world.  Biological laws apply to us like very other species but for financial and social reasons we don’t want to bite the bullet.”

(click slide image to expand)

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