Science and Implementation Plan: Appendix

Supporting Statements from Scientific Panel Reports

Concern about ice-sheet collapse raising sea level is not new. Research on this critical subject has been identified and endorsed by many panels of distinguished Earth scientists. By taking a multidisciplinary approach, WAIS satisfies many separate research elements ranked as priority research by these panels. What follows are statements supporting the WAIS goal excerpted from these reports.

A.1 Our Changing Planet: The FY 1990 Research Plan. The U.S. Global Change Research Program, Interagency Committee on Earth Sciences, 1989

"High Priority Research Needs:

Ice Sheet Mass Balance. The most important area of research in the cryosphere is to determine the mass balance of the ice sheets...and determine how their respective mass balances are changing...because of the linkage of negative mass balance in glaciers to rising sea level [p. 36]...

Sea Ice and the Oceans. The dynamics and thermodynamics of the interaction between sea ice and the ocean and the influence of sea ice on both ocean circulation and climate require further study [p.36]...

Ice-Ocean-Atmosphere Coupling. Much improved models are needed to link climate change to glacier mass balance changes and changes in sea level, so that the glacial component of sea-level change can be predicted. In addition, second-generation, three-dimensional ice-sheet models, which include thermodynamics, ocean coupling, and feedback effects of solid Earth deformation, are needed to simulate the present state of the polar ice sheets and to predict the response of ice sheets to climate change. A better model of a marine-based ice sheet, such as the West Antarctic ice sheet, is needed to produce a coupled glacier ice-ocean-atmosphere model [p. 39]."

A.2 Earth System Science, A Closer View, Earth Systems Sciences Committee, NASA Advisory Council, 1988

"Interactive ocean-atmosphere-ice models..." are identified as an important research focus for studying the Earth system on time scales of decades to centuries (p. 152).

The following parameters are listed as providing a fundamental description of the Earth (Tables 9.1A and 9.1B):

Importance/ Parameter

Essential / Ice Volume and Extent

High / Sea Level

Substantial / Ice-Sheet Surface Elevation and Ice-Sheet Volume Changes

A.3 The Role of Antarctica in Global Change, Scientific Priorities for the International Geosphere-Biosphere Program (IGBP), Scientific Committee on Antarctic Research (SCAR) Steering Committee for the IGBP, (1989)

"Tasks that must be included in an Antarctic component of the IGBP include:

To monitor the rate and extent of change in the Antarctic sea ice, atmosphere, ocean and biota, and study their interactions;

To establish a system to measure changes in Antarctic snow accumulation and ice flow likely to affect ice mass balance and sea level;

To clarify further the past global environmental changes using deep ice cores and sediment records from Antarctica." (p. 5)

A.4 Glaciers, Ice Sheets, and Sea Level: Effects of a CO2-Induced Climatic Change, Committee on Glaciology, Polar Research Board, National Research Council, 1985

"The physics of the dynamic response of the ice sheets to variations in climate is known in general terms, but some processes are not well understood or have not yet been incorporated fully in numerical models. Major gaps in understanding concern basal sliding, the coupling of ice streams with the ice sheets in which they are embedded, and what determines the position of the seaward (calving) face of ice shelves [p. 3]...

In the case of the West Antarctic Ice Sheet, the situation is further complicated by the possibly delicate stability of the interaction between ice streams and ice shelves. If melting from the base of ice shelves were to increase markedly, the effect on ice streams could be far more important than the expected minor increase in surface melting and runoff. [p. 4]"

A.5 Environment of West Antarctica: Potential CO2-Induced Changes, Committee on Glaciology, Polar Research Board, National Research Council, 1984

"It has been suggested that a rapid reduction of the ice mass of West Antarctica leading to a drastic rise in sea level might occur as a consequence of CO2-induced warming.

The existing West Antarctic environment is inadequately described by the available observations. This conclusion holds both for the general atmospheric and oceanic circulations and for their specific manifestations: the mass and energy balances of the inland ice sheet, the ice shelves, and the surrounding sea ice. [p. 1]...

This rise in sea level [caused by a rise in CO2] will be relatively manageable in the next century unless, as some scientists have suggested, the warming triggers a rapid reduction in the ice mass of the West Antarctic Ice Sheet. In order to assess the possibility that this would happen, two kinds of studies are required. First, the external climate factors that influence the West Antarctic Ice Sheet-mainly precipitation, summer temperature, and oceanic heat flux-need to be known. Second, the dynamic response of the ice sheet/ice stream/ice shelf system to changes in this external forcing needs to be understood. [p. 4]"

A.6 U.S. Research in Antarctica in 2000 A.D. and Beyond, A Preliminary Assessment, Polar Research Board, National Research Council, 1986

"OUTLOOK BEYOND 2000 A.D.

...the scientific priorities for antarctic research will most likely reflect the global issues of pollution, climate change habitability, resources, geotectonics, and other large-scale problems.

Examples of just a few of the many specific global questions that may be addressed include the following:

* The stability of the West Antarctic Ice Sheet in the face of the anticipated global warming...

* The role of the Antarctic in forcing the global atmosphere and ocean...

* The intensity of the antarctic-driven forcing system, the parameters that control it, and its fluctuations with time. [pp. 13-14]...

Glaciology's recent exciting discoveries and advances are expected to continue with regard to understanding the role of ice in climate, documenting the climate of the past, determining the stability of the ice sheets, and assessing the potential future impact of the antarctic ice sheet on sea level. [p. 21]"

A.7 Antarctic Solid-Earth Sciences Research: A Guide to the Next Decade and Beyond, Ad Hoc Committee on Antarctic Geosciences, Polar Research Board, National Research Council, 1986

"The following are the most important broad topical problems...that we recommend be investigated during the next decade of Antarctic geoscience research:...

Category A: Antarctic Problems with Global Implications. [p. 8]...

. The reconstruction of a more detailed history of the Antarctic Ice Sheet and the definition of the physical, geological, and biological responses to it on both the regional and global scale [p. 9]."