Antarctica and its surrounding ocean are dominated and shaped by the presence of snow and ice which, while themselves controlled by the climatic regime and very sensitive to climate change, also influence and provide major feedbacks to the global climate system.

Many globally significant processes are driven by the unique climate and geography of the Antarctic region. These include the uptake of carbon dioxide by the Southern Ocean; the overturning circulation of the deep ocean; the balance between water storage and discharge in the main continental ice-sheet; changes in surface energy, mass and momentum exchange by ice masses; and energy transfer between all levels of the atmosphere to space. Understanding these processes is vital for understanding and predicting climate and environmental changes and their impacts. These impacts include future greenhouse gas levels, sea-level rise, the variability and rate of change of climate, and changes in atmospheric composition.