Climate Change

ASOC Publications on the Antarctic and Climate Change:

Policy Implications Arising from SCAR's Report:  Antarctic Climate Change and the Environment (Paper from ATCM 2009)

Impacts of Climate Change on Antarctic Ecosystems (Paper from ATCM 2008)

Impacts of Climate Change on Antarctic Ecosystems (Paper from CCAMLR 2008)

Global Climate Change, Antarctica, and Krill (article from the Antarctic Krill Conservation Project)

Climate Change and the Implementation of CCAMLR's Objectives (Paper from CCAMLR 2007)

The Antarctic and Climate Change (Paper from ATCM 2007)

The Antarctic and Climate Change (Paper from ATCM 2006)

The Antarctic and Climate Change (Paper from ATCM 2005)

A Short Bibliography, with abbreviated abstracts, on Antarctic Climate Change. Included are references to papers on " The meteorological viewpoint," " The past record from ice cores," "The collapse of the Larsen Ice Shelf," The West Antarctic Ice sheet (WAIS)," " The WAIS as a whole," and " The Antarctic ice sheet as a whole."

Summaries of SCAR Scientific Research Programmes

News from the Scientific Committee on Antarctic Research
"Antarctic Climate Change and the Environment" report
Following production of the Arctic Climate Impact Assessment report in 2005, SCAR decided that a southern hemisphere equivalent was required, and set about producing it. 100 scientists from 13 countries contributed as authors, and the manuscript was worked up by an editorial team of 9, headed by Dr John Turner of the British Antarctic Survey - reflecting the fact that the work began as a project of SCAR's "Antarctica in the Global Climate System" (AGCS) scientific research programme, of which he was at the time the scientific leader. The project expanded through time to incorporate the past climate dimension, provided by scientists from SCAR's "Antarctic Climate Evolution" (ACE) programme, and the biological impacts, provided by scientists from SCAR's "Evolution and Biodiversity in the Antarctic"(EBA) programme.

The completed report was printed in October 2009 and has been mailed to authors and to the Heads of Delegations to the 15th Conference of the Parties of the UN Framework Convention on Climate Change (COP 15), which took place in Copenhagen in December 2009. SCAR produced only 500 hard copies, having decided that this ought to be a web-based product that was readily available at no cost to the entire scientific community. Remaining hard copies will in addition go to SCAR national committees and delegates, to COMNAP and to the Treaty Parties as well as to a wide selection of polar and other libraries. Elements of the report have already been published as scientific papers in Reviews of Geophysics (January 2009) and will appear in the December issue of the Antarctic Science Journal. Annual reviews of the science of climate change in the Antarctic, based on the ongoing work in the report, have been presented to the Antarctic Treaty Consultative Meetings and the associated Committee for Environmental Protection.

The editors are most grateful to the many authors who contributed text, to the many reviewers who commented on the circulated drafts in summer 2007 and summer 2008, and to their parent institutions for allowing them the time to contribute to this magnum opus. SCAR will continue supplying annual updates on climate to the ATCM, and will in due course update the ACCE report itself as the science evolves. Thanks go to all those involved in the report's production, and to BAS for providing support for the press conference at the Science Media Centre in London on November 30, at which the book was formally launched.

The report is available from the ACCE page of the SCAR website, along with copies of the press release, and a document detailing the main 10 points from the report. For further enquiries, consult the SCAR Executive Director at cps32@cam.ac.uk

Meeting report and poster available on the Southern Ocean Observing System
The latest meeting report of the SCAR/SCOR Oceanography Expert Group, focussing on the Southern Ocean Observing System (SOOS), is now available as SCAR Report 35, as is a poster from the OceanObs09 conference. The goal of the SOOS is to provide the sustained multi- disciplinary observations needed to detect, interpret and respond to changes in the Southern Ocean. The Oceanography Expert Group, in consultation with other groups and invited experts, is currently finalising a draft of the SOOS planning document, which will be available for comment by the community sometime in December.

The Antarctic and Climate Change:  A Summary

Antarctica comprises two geologically distinct regions, East Antarctica and West Antarctica, separated by the great Trans-Antarctic Mountains but joined together by the all-encompassing ice sheet. The presence of the high ice sheet and the polar location make Antarctica a powerful heat sink that strongly affects the climate of the whole Earth. Furthermore, the annual sea ice cover around the continent, which seasonally reaches an area greater than that of the continent itself, modulates exchanges of heat, moisture, and gases between the atmosphere and ocean and, through salt rejection when it freezes, forces the formation of cold oceanic bottom waters that spread out under the world’s oceans.

Both the ice sheet and the sea ice are potentially subject to change in a changing climate; the ice sheet, in fact, may be changing now in response to past climate change. The greatest threat to the inhabited world comes from the West Antarctic ice sheet (WAIS), which rests on a bed far below sea level and so may have the potential for rapid shrinkage. The Antarctic is so vast, remote, and difficult to monitor, however, and the physical behavior of the ice sheet so complex, that there is as yet no definitive demonstration (or disproof) of such change, even though a pronounced climatic warming is ongoing in one northerly portion of the continent. Measurements from satellites early in the 21st century should settle the question of current growth or shrinkage, but prediction will remain problematic for many years. See C. R. Bentley. 2002. Antarctica. In T. Munn, ed., Encyclopedia of Global Environmental Change, Volume 1, The Earth system: physical and chemical dimensions of global environmental change, M. C MacCracken and J. S Perry, eds, John Wiley & Sons, 184–189.

The Antarctic ice sheet contains sufficient ice to raise world-wide sea level by more than 60 meters if melted completely. The amount of snow deposited annually on the ice sheet is equivalent to about 5mm of global sea level, as is the mean annual discharge of ice back into the ocean. Thus, a modest imbalance between the input and output of ice might be a major contributor to the present-day rise in sea level (1.5–2mm per year), but the uncertainty is large.

Despite all available measurements of snow accumulation, ice velocities, surface and basal melting, and iceberg discharge, it is still not known for certain whether the ice sheet is growing or shrinking. The uncertainty in the estimate of the total mass balance is at least 20% of the mass input, equivalent to a global sea-level change of about 1mm per year. Furthermore, the fact that rates of discharge from some of the Antarctic ice streams have changed markedly in recent decades and centuries suggests that the mass balance also may be rapidly changeable.

The volume and geographic extent of the Antarctic ice sheet certainly have undergone major changes over geological time. The ice sheet was significantly larger during the last glacial maximum, some 20,000 years ago, and retreated to near its present extent within the last several thousand years; that retreat is probably on-going at present. Several mechanisms in the ice-sheet–lithosphere system, notably post-glacial isostatic uplift and the effect of temperature on the viscosity of the ice in the deeper layers, have long response times. It is likely that the ice sheet is still reacting dynamically to the glacial–inter-glacial transition between 20,000 and 10,000 years ago and to the subsequent increase in the snow accumulation rate. Consequently, the present Antarctic contribution to sea-level change (whatever it may be) could reflect changes in the accumulation rate over the past 100 years, or the long-term dynamical response of the ice sheet, or both.

Future enhanced greenhouse warming will affect the mass balance of the ice sheet. Oceanic warming could increase basal melting of the floating ice shelves, whose thinning could result in faster flow of the ice into the ocean, contributing to sea-level rise. On the other hand, atmospheric warming and reduction in sea-ice cover almost surely will give rise to increased precipitation over the continent, thereby contributing to sea-level.

Realistic predictions of the response of Antarctica to enhanced greenhouse warming and the resulting sea-level contribution will not be possible until the present mass balance is determined and a better understanding of the atmosphere–ice–ocean processes and ice dynamics is developed. See C. R. Bentley, 2003. Mass balance of the Antarctic ice sheet: observational aspects. In J. L. Bamber and A. J. Payne, eds, Mass Balance of the Cryosphere: Observations and Modelling of Contemporary and Future Changes. Cambridge University Press, 459-489.

Climate Change and the Marine Stewardship Council (MSC)

The MSC is proposing to certify two fisheries in the Southern Ocean as sustainable.  However, their methodology fails to account for the effects of climate change, an omission which ASOC believes will make sustainable management of these fisheries nearly impossible.  Read more about our concerns on this issue here.

External Links:

The Scientific Committee on Antarctic Research (SCAR) is the international coordinating body for national programs of Antarctic research. International Scientific Research Programmes sponsored by SCAR: http://www.scar.org/researchgroups/

An extensive list of web sites on Arctic and Antarctic regions, and on Polar Research (from Scott Polar Research Institute): http://www.spri.cam.ac.uk/links/general.html

Photos and movies of the Larsen ice Shelf (from Scott Polar Research Institute): http://www.spri.cam.ac.uk/research/cpom/lis/

A description of the West Antarctic Ice Sheet research initiative, with many links (from Robert Bindschadler, NASA Goddard Space Flight Center): http://igloo.gsfc.nasa.gov/wais/