The polar regions have experienced some remarkable environmental changes in recent decades, such as the Antarctic ozone hole, the loss of large amounts of sea ice from the Arctic Ocean and major warming on the Antarctic Peninsula. The polar regions are also predicted to warm more than any other region on Earth over the next century if greenhouse gas concentrations continue to rise. Yet trying to separate natural climate variability from anthropogenic factors still presents many problems. This book presents a thorough review of how the polar climates have changed over the last million years and sets recent changes within a long term perspective. The approach taken is highly cross-disciplinary and the close links between the atmosphere, ocean and ice at high latitudes are stressed. The volume will be invaluable for researchers and advanced students in polar science, climatology, global change, meteorology, oceanography and glaciology.