ANTARCTIC
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 Human and Environment Interaction
By Meghan

Antarctica is the only continent that does not have any permanent residents living on it.  Many nations have tried to lay claim to this region but none have fully succeeded.  In 1959, twelve states that were active in the Antarctic region began negotiating what is now known as the Antarctic Treaty System. These nations included Argentina, Australia, Belgium, Chile, the French Republic, Japan, New Zealand, Norway, the Union of South Africa, the Union of Soviet Socialist Republics, the United Kingdom of Great Britain and Northern Ireland, and the United States of America.   The Antarctic Treaty was ratified in 1961 and has remained a major influence on Antarctic affairs.  In the treaty, Antarctica is defined as all land and ice shelves south of the southern 60th parallel. The treaty has now been signed by 44 countries, with the understanding that Antarctica is to be left as a scientific preserve, establishing freedom of scientific investigation and bans all military activity on the continent.

Today, Antarctica is visited by about 4,000 researchers and tourists during the summer months (October through the end of February) with only about 1,000 people remaining through the harsh, winter months.  These people that remain, live mostly at government research stations along the coastal regions.  Mean temperatures in the interior of the continent during the coldest month (August) range from -40° to -70°C (-40°to -94°F). Winter temperatures can drop to -121 °F to -130 °F (-85 °C and -90 °C) and by the middle of winter, so much of the sea around the continent freezes into pack ice that it basically doubles in size.  It is much like a frozen desert with very little precipitation, especially at the South Pole itself. This, coupled with harsh, hurricane force winds and blizzards makes traveling in and out of the region virtually impossible during the winter.  Also, the instability of the shifting ice layers and the blowing and drifting snow that piles up around structures make it difficult to even build and maintain access to buildings during the winter months.  This very harsh environment makes permanent settlements and buildings to house people year around highly unlikely.

Antarctica's summer months do bring somewhat warmer temperatures with mean temperatures ranging from -15° to -45°C (5° to -49°F).   This is the time of year when most scientific research can be performed and transportation in and out of the area is safest. Temperatures are warmer on the sub-Antarctic islands ranging from about -40°C in August to +14°C in January or February (-40°to +50°F).

Visitors to Antarctica, whether for research purposes or through tour organizations, must comply with environmental requirements and other obligations outlined in the Antarctic Treaty System.  These requirements include thorough planning of the expeditions (including prior environmental assessment) and complete self-sufficiency.  The most important legal requirements relate to prior environmental assessment of the proposed activities, prohibition on taking or harming flora and fauna, waste disposal, contingency planning and the need for permits if visits to protected areas are part of the trip.  Also, an international non-governmental organization, known as the Scientific Committee on Antarctic Research(SCAR) was formed by the member nations to help coordinate scientific research in Antarctica. 

Environmental issues that are studied in the Antarctic region include marine life and habitats, climatology and global warming related issues, measuring and studying ozone, and astronomy. The South Pole happens to be one of the best places in the world to study astronomy due to the high altitude of the ice cap and the low precipitation.

The climate in Antarctica as well as the Arctic has a profound affect on the climate in other areas around the globe.  Thus, changes in the climate at either pole can have an affect on weather patterns and ocean currents and ultimately on environments, ecosystems and human society.  This is why it is important to study polar climates and how they interact with polar environments, ecosystems and societies. By studying these polar climates and getting a better picture of conditions at the poles and how they interact and influence the oceans, atmosphere and land masses, the science community can develop a better understanding of the current global climate and what might happen in the future.

Unfortunately, existing climate models have thus far failed to predict the dramatic break-up of Antarctic ice shelves such as the Larson B Ice Shelf on the Antarctic Peninsula. Part of this ice shelf, bigger than the size of Rhode Island, broke off and floated out to sea between January and March 6 of 2002. A great video of the break up is on Tom Brokaw's documentary. Again in January, 2005 another piece broke off the Larson B Ice Shelf known as Iceberg 53 and in the Arctic region, the Ayles Ice Shelf on Ellesmere Island, the size of 14,000 football fields, broke free and is now floating in the sea. The three fastest warming regions on the planet in the last two decades have been Alaska, Siberia and parts of the Antarctic Peninsula.  This indicates that the Polar Regions are highly sensitive to climate change and this raises real concern for the future of polar ecosystems and Arctic life.

Scientists believe we are currently in an “interglacial” period, where the ice is gradually retreating – a phenomenon very much in keeping with past cycles.  However, it is thought that a slight drop in mean summer temperatures, of as little as 2-3 degrees Celsius of 4-5 degrees F, would allow seasonal snow fields to persist year round and develop into ice sheets.  Conversely, a slight rise in mean temperatures could cause more melting and break up of the continental ice sheets.  It’s possible the ice could return or disappear altogether.  Our impact on the Earth, especially our release of atmosphere-altering gases may be enough to not only alter natural forces but amplify them.

Scientists have been studying the man made phenomenon considered to be the most dangerous to the Antarctic environment called the Greenhouse Effect.  Our cars and factories are producing so much carbon dioxide that plants can’t absorb it all whether through photosynthesis or by plankton which normally absorb carbon dioxide in the sea.  At the same time, increasing populations and the destruction of forests, particularly rainforests, are occurring at a fast pace around the world.  This has created a surplus of carbon dioxide in the atmosphere which helps trap the sun’s heat within the earth’s atmosphere creating a progressive rise in the earth’s average temperature.  Scientists believe that even small increases in overall temperatures at the poles could be enough to melt large areas of ice and raise sea levels around the world.

Ozone is a major concern of scientists in the polar regions.  Ozone is a form of oxygen that is created naturally in the stratosphere, the atmospheric band (9-28 miles) above the surface of the earth.  It plays an important role in absorbing harmful ultraviolet (UV) radiation before it reaches the earth’s surface.  Ozone has been monitored by scientists for over 50 years.  However, in the 1970’s and 1980’s the ozone appeared to be thinning in areas especially over Antarctica.  A “hole” can now be observed over Antarctica and it appears to follow an annual cycle.  Every Antarctic spring (October) ozone values fall to less than half their normal amount and the ozone hole covers the entire continent. Sometimes the ozone hole becomes very elongated and can cross over the southernmost part of South America and the Falkland Islands. By mid summer the ozone hole has filled in, and the cycle then repeats the following year.

The thinning of stratospheric ozone is caused by a buildup during the cold winter months of chemicals containing chlorine and bromine.  These chemicals are released when the sun returns in late August, triggering the reaction that destroys the ozone.  Depletion of the ozone layer is related to both human-produced and natural factors such as volcanic eruptions, varying solar cycles and sunspot activity and the natural evolution of the atmosphere.  Most of the thinning is linked to the manufacture and release of ozone-depleting substances (ODSs) namely chlorofluorocarbons (CFCs), bromofluorocarbons (halons), methyl chloroform, carbon tetrachloride, methyl bromide and hydrochlorofluorocarbons (HCFCs).  In many countries, these ODSs are used in refrigerators, air conditioners, foams, aerosol sprays, fire extinguishing systems, pesticides and solvents. Commercial uses of ODSs first began in the 1930's and this long-term use combined with their atmospheric lifetimes (up to 100 years for some) have resulted in a large ODSs build up in the stratosphere. Even if ODSs could be banned around the world, their longevity after they are released means their concentrations would continue to rise and continue to react with the ozone layer for many years.  

Depletion of stratospheric ozone increases the level of ultraviolet (UV) radiation at ground level. Excessive exposure to UV is known to cause sunburn and has been linked to skin cancer, suppression of the immune system, and increased risk of developing cataracts in humans.  Although all of these chemicals- both man made and naturally occurring – are generated from sources all over the planet, the high level belt of circular winds over the Antarctic, known as the Polar Vortex, tends to concentrate them there over Antarctica.  Therefore, it is important that scientists continue to monitor changes in the Antarctic region with respect to global warming, climate changes and ozone depletion, because what chemicals we use today can be affecting how we will be living in the future.