Draft Proposal 2004 - page 5

Anthropogenic Impact - The influence of human activity on climate and atmospheric composition over Antarctica has already had profound effects. Unexpectedly, the continent has been subjected to massive ozone depletion as a consequence of its unique setting in relationship to global circulation systems and the introduction of humanly engineered CFCs that are able to destroy ozone. Recent changes in Antarctic snow accumulation and sea ice extent have been linked, in principle, to greenhouse gas warming (Morgan et al., 1991; Thompson et al., 1994; Vaughan and Doake, 1996). Human source nuclear fallout from bomb tests and the Chernobyl nuclear accident (Dibb et al., 1990) demonstrate the potential for the introduction of a variety of anthropogenic source pollutants to the continent.

Ice Dynamics and the Climate/Sea Level Connection

Antarctica’s role in global climate is largely propagated through changes in its ice cover. The scale of this connection ranges from seasonal changes in sea ice extent that cause changes in albedo, atmospheric circulation, ocean productivity, and ocean circulation to potentially massive changes in sea level triggered by collapse of portions of the Antarctic ice sheet. Much of the ice in West Antarctica and portions of coastal East Antarctica is grounded below sea level, and is therefore inherently unstable. Geologic evidence affirms the potential for catastrophic disappearance of such marine-grounded ice sheets in the Northern Hemisphere. The potential exists for future ice sheet collapse in response to humanly forced changes in climate. There is sufficient marine-grounded ice in the region of particularly West Antarctica to raise sea level several meters, and immense potential for dramatic influences in the production of Antarctic bottom water as a consequence of changes in both West and coastal East Antarctica. Precise measurements of these changes are now becoming available (e.g. Wingham et al., 1998; Hamilton et al., 1998) but they are of limited distribution, require careful interpretation, and exhibit spatial variability.

Assessing Climate Change in Antarctica Through ITASE – The Role of ITASE in IGBP and SCAR

ITASE evolved from discussions between representatives from several national ice coring programs during a meeting hosted by the European Science Foundation in Grenoble, France in 1990. Twelve nations formulated the original concept (Australia, Canada, China, France, Italy, Germany, Japan, Russia, Sweden, Switzerland, the United Kingdom and the United States). Scientists from Belgium, Brazil, Chile, India, Korea, New Zealand and Norway have since joined the program. Since the initiation of ITASE, several international workshops have been held for purposes of organization and data interpretation. One of these workshops led to the development of an international Science and Implementation Plan for ITASE (Mayewski and Goodwin, 1997, see the Science and Implementation Plan. Other workshops have taken place in Durham, New Hampshire (March 1999), Potsdam, Germany (September 2002) and Milan, Italy (August 2003). These workshops, sponsored by SCAR and IGBP, have provided important venues for data sharing, concept development, and coordinated logistics planning.

ITASE was formally accepted in 1991 by the Scientific Committee on Antarctic Research (SCAR) as one of its primary initiatives, GLOCHANT (Global Change in Antarctica). As a consequence of the reorganization of SCAR in 2001, ITASE is now officially a Scientific Programme Group. It was adopted as an IGBP (International Geosphere-Biosphere Program) PAGES (Past Global Changes) Project in 1993 under PAGES Focus II. The first SCAR sponsored ITASE Project Office was housed at the University of Tasmania, Australia (I. Goodwin, Director). As of 2001 the SCAR ITASE Project Office moved to the University of Maine.

Previous page, Next page