15.1 Introduction

The polar regions are increasingly recognised as being:

• geopolitically and economically important,
• extremely vulnerable to current and projected climate change,
• the regions with the greatest potential to affect global climate and thus human populations and biodiversity.

Sub-regions of the Arctic and Antarctic have shown the most rapid rates of warming in recent years. Substantial environmental impacts of climate change show profound regional differences both within and between the polar regions, and enormous complexity in their interactions. The impacts of this climate change in the polar regions over the next 100 years will exceed the impacts forecast for many other regions and will produce feedbacks that will have globally significant consequences. However, the complexity of response in biological and human systems, and the fact that these systems are subject to multiple stressors, means that future impacts remain very difficult to predict.