Ice sheet

Abstract

The two remaining polar ice sheets are the cornerstone of the global cryosphere and climate systems. They are sensitively balanced through processes of growth, flow, and loss, and comprise a number of glaciological components that are key to maintaining this balance (including inland centers, ice streams, and ice shelves). However, the ice sheets may be threatened by future warming of the planet, which is projected to rise significantly over coming centuries. Indeed, whether driven by humans, or by the natural cycles of the Earth, there is evidence that parts of the polar ice sheets are already undergoing major changes. Geological clues from the past hint at times when ice sheets were completely disintegrated, and demonstrate that the current rates of change are unusual in the context of longer-term ice dynamics. However, while we know much about the history of ice sheets and their present-day operating mode, their future behavior remains a continual uncertainty. Thus, many lines of enquiry form an ongoing programme of research into ice sheets, their past, present, and future changes.