Ice sheets: indicators and instruments of climate change

Ice sheets of Greenland and Antarctica are uniquely arresting and captivating features of the Earth’s natural environment. The hyperbole attached to their description, their sheer size and remoteness from the normal lives of most of us, guarantees their iconic status, but the emerging understanding that ice sheets contain a threat, which cannot be fully evaluated mean, that they have become a central issue in the climate change debate. However, while global climate has undoubtedly warmed during the recent past, and human activity has been a major factor in this change, the role of ice sheets as indicators of climate change and as influential components in the planets climate engine, is a complex one (Fig. 1). This chapter will discuss the position of the great ice sheets within the climate change debate, contrasting the differing risks posed to sea-level rise by the Greenland and Antarctic ice sheets as likely contributors to future sea-level rise, and how they may differently influence the wider debate on limiting greenhouse-gas emissions