Dr John Shears is an Environmental Officer at British Antarctic Survey
I've been wondering for some time, when standing on the South Pole holding a compass, is every direction North? I see on the map in this article that there is East and West Antarctica but how can this be?
Correct. If you are standing at the geographic South Pole (90 degrees South) then every direction is North. The place names East and West Antarctica suggest themselves because all of West Antarctica lies within the Western hemisphere and almost all of East Antarctica lies within the Eastern hemisphere. These place names have been in existence for about a century, but have become more widely used and recognised since the International Geophysical Year (1957-58) and geographical exploration showing that the Transantarctic Mountains give a useful regional separation of the continent into East and West Antarctica.
How does global warming threaten Antarctica?
The Intergovernmental Panel on Climate Change (IPCC) has determined that global warming was 0.6 +/- 0.2 degrees C during the 20th century and concluded that most of the observed warming has been due to the increase in greenhouse gas concentrations.
Global warming of Antarctica is of concern because the continental ice sheets contain vast reserves of water and increased melting of this ice in a warmer world could contribute to global sea level rise.
Global climate computer model predictions of how the Antarctic climate may change over the next 100 years differ in detail from model to model. Most models, however, indicate relatively modest temperature increases around Antarctica over the next 50 years. Over this time period, the models predict increased snowfall over Antarctica, which should more than compensate for increased melting of Antarctic ice. However, many natural processes occurring in the Antarctic are not well represented in present climate models and further research is needed to improve our confidence in these predictions.
The central and southern parts of the west coast of the Antarctic Peninsula is one region of the continent where detectable climate change is occurring. Climate records from this region extend back 50 years and show that annual mean temperatures have risen by over 3 degrees C, making it one of the fastest warming regions on Earth. However, scientists do not yet know whether this rapid regional warming is a natural event or linked to increased greenhouse gas emissions from human activities.
The observed warming of the Antarctic Peninsula region has already had a significant impact on the region and has led to the retreat of glaciers, reduction in snow cover and the retreat and collapse of the northern ice shelves. There has also been a reduction in the duration of winter sea ice. The warming has caused significant changes in lake ecosystems and promoted the expansion of populations of native flowering plants. The distribution of penguin populations is also changing as the climate warms. Adelie penguins, which require access to winter sea ice, appear to be declining on the central west coast of the Antarctic Peninsula, whilst Gentoo and chinstrap penguins, which occur near open water, are increasing.
With the growing economic and population pressures that face the 21st century, and the subsequent dramatic increase in energy needs, will Antarctica ever be used for wide spread oil exploration? And what would be the potential environmental effects on Antarctica's fragile environment?
Mining, including oil exploration, is banned in the Antarctic by the Environmental Protocol to the Antarctic Treaty (1998). There are no plans by the Antarctic Treaty nations to reverse the minerals ban, although the Environmental Protocol allows for the prohibition to be reviewed after fifty years.
There are no known economic mineral deposits in Antarctica, although coal and minerals, such as copper, have been found in small quantities by geologists. If mining were to take place it would be very costly and a major technical challenge because of the freezing cold weather conditions, rough seas, sea ice, and the long distances to commercial markets in South America, South Africa or Asia.
The potential effects of mining on the Antarctic environment could be serious. Probably the most significant impacts would be oil spills from tankers transporting crude oil from Antarctica to the rest of the world. It would be very difficult to clean-up a large crude oil spill in Antarctica, and if it occurred in an inshore area near to penguin colonies or seal breeding beaches then many animals could become coated in oil and die. The oil spill from the tanker Exxon Valdez in Alaska in 1989 has shown that even relatively small crude oil spills in coastal polar regions can have major and long-lasting environmental impacts.
Do you see tourism as a potential threat to the Antarctica ecosystem, or are there benefits to its development?
Tourism is a major activity in Antarctica, and each year about 12 - 13,000 tourists visit the continent. The vast majority travel there by tour ship, with around 20 tour ships operating in the region, mostly in the Antarctic Peninsula, each season.
Compared to other regions of the world, the overall number of tourists visiting Antarctica remains relatively low. For example, over 40,000 plus ship-borne tourists now visit Svalbard in the Arctic each year.
At current levels, there is no evidence that ship-borne tourism in the Antarctic has had a detrimental impact on either the Antarctic environment, or on science activities. This is demonstrated by the historic British base at Port Lockroy, Antarctic Peninsula, which is open to visitors each summer season. The base is now one of Antarctica's most visited sites, attracting over 9000 people a year. The base is also the site of a Gentoo penguin colony with 720 breeding pairs. The British Antarctic Survey (BAS) has been monitoring the breeding success of the penguins since 1996, when the base reopened. The results show that tourists have had no discernible impact on penguin breeding success, which instead is related to food availability and snow cover.
Most tourist ships operating in Antarctica are relatively small (both in tonnage and tourist carrying capacity), and are diesel powered. This ensures that tourist numbers ashore are easily managed, and that, even in the event of a major maritime accident involving a grounding or sinking, any environmental impact is likely to be relatively contained. Nearly all the small tour ships are members of the International Association of Antarctica Tour Operators (IAATO). This Association self-regulates its members and has established strict bye-laws, for example on numbers of tourists allowed to go ashore, to ensure that the Antarctic environment is not damaged.
But in the last couple of years several large tourist vessels, which are not IAATO members, have started operations in Antarctic waters. These vessels pose greater environmental and health and safety risks. Rarely, are such large ships ice-strengthened, whilst they are more likely to be fuelled by heavy bunker fuel oil carried in much greater quantities. In the event of a maritime accident serious, more long-lasting pollution may result. In addition there is a significant risk of major loss of life because of the hostile environment, and the inadequacy of current search and rescue (SAR) services to cope with such demands. To help address this problem the UK Government is pressing for Safety Guidelines to be adopted by the Antarctic Treaty nations for all ships operating in Antarctic waters.
As well as threats there are also benefits of Antarctic tourism. Most tourists who visit Antarctica have a wonderful holiday and see fabulous scenery and wildlife. When they return home they frequently act as "ambassadors" for Antarctica and help to promote the environmental protection of the continent and the important scientific research carried out there.
John was interviewed in June 2004