The ice-free areas of Antarctica comprise less than 2 per cent of the
total land area of the continent. These areas are largely found on the
continental coastline (particularly in the Peninsula area) and on the
islands south of 60º. The ice-free areas are biologically active sites
with relatively easy access. They are therefore also the focus of increasing
human activities and infrastructure. Threats to Antarctic land arise from
this human activity, and threats to the ice sheets arise both as a result
of this activity and, more importantly, from global climate change.
|The Madrid Protocol on Environmental Protection
The Madrid Protocol on Environmental Protection to the Antarctic
Treaty came into force in 1998. The signing of the protocol significantly
strengthened the environmental objectives of the Antarctic Treaty.
It requires, among other things, that all activities be planned
and conducted so as to limit adverse impacts on the Antarctic environment
and dependent and associated ecosystems. The Madrid Protocol also
defines a framework for protected areas, enabling special protection
of unique, important or especially vulnerable areas.
It is yet too early to assess the effectiveness of the provisions
of the Madrid Protocol. However, some environmental measures adopted
since the Protocol have already proved efficient. For example, in
1992 the National Antarctic operators developed guidelines for fuel
handling and emergency response. Since then, a gradual decrease
in the number of reported incidents per year has been recorded,
indicating that these recommendations are being implemented and
are effective (COMNAP 2000a).
The risks associated with human uses of ice-free areas are related to
potential local pollution due to oil spills, deposition of combustion
products and sewage, habitat loss, terrain modification, disturbance to
wildlife due to operations and human presence and introduction of exotic
species and disease. However, so far little is known about the long-term
and cumulative significance of these impacts.
There are now 70 research stations in Antarctica; half operate throughout
the entire year and almost half are located in the Peninsula region (COMNAP
2000b). Few are located in ice-covered areas. Half of today's operative
stations were constructed before 1970. In addition to this scientific
activity, tourism in Antarctica is also increasing.
Ice covers 98 per cent of the Antarctic continent. The mass balance of
this Antarctic ice sheet is of global concern, particularly in view of
the impact on sea level of ice melting. The mass of ice is growing over
most of East Antarctica although coastal regions tend to be near balance
with some losses around some of the large ice shelves and coastal ice
streams (Budd, Coutts and Warner 1998). The ice masses of Antarctica are
therefore increasing rather than decreasing on a continental level (Vaughan
and others 1999). However, the ice shelves in the Antarctic Peninsula
continue to disintegrate because of regional warming. A total area loss
of 6 300 km2 was observed for the Larsen ice
shelf between 1975 and 1998 (Skvarca and others 1999) and an additional
1 714 km2 was lost during the 1998-99 season.
Iceberg break-up is consistent with global warming but is not a proof
of it. Melting of marginal ice shelves in the Antarctic Peninsula is,
however, not expected to have significant and direct effects on sea level