Antarctica is probably the least known of the world’s regions. Intensive research by over 20 nations during the past 30 years has demonstrated increasingly the integral and often critical role of Antarctica in the natural systems of planet Earth. The Antarctic is fundamental in driving the global atmospheric regime owing to its strong negative radiation budget, and the Southern Ocean, linking the Atlantic, Indian and Pacific oceans, plays an influential, but not well understood role as a major sink for carbon dioxide. Man induced increases in ‘greenhouse’ gases are likely to have profound effects on the lower atmosphere of the South Polar regions where general circulation modelling predicts a strong temperature change response. The reaction of the ice sheet to warming is complex and includes ice shelf–sheet destruction as well as increased snow accumulation, both of which affect world sea level. Antarctica also forms an ideal observatory for studying the processes whereby solar radiation and particle outflow directly influence the Earth’s environment through energy transfer to the upper atmosphere. The presence of chlorafluorocarbons in the stratosphere has resulted in the depletion of ozone in the austral spring, a discovery by the British Antarctic Survey that above all others has given a place to Antarctica on the world environmental stage.