What is the overall state of the Arctic environment? The aim of this report is to answer the many aspects of this seemingly straightforward question. Although several national and international efforts have looked at parts of the Arctic, this is the first attempt to assess the state of Arctic flora and fauna as a whole.

This feature article provides a summary of study about the role of clouds in the balance. Until recently, scientists were uncertain whether clouds had an overall net cooling or heating effect on the Earth's climate. But recent studies show that, in the tropics, a "near cancellation" between shortwave cooling and longwave warming exists, which indicates that the amount of incoming radiant energy is roughly equal to the amount of outgoing radiation. However, small changes in tropical cloudiness can disrupt this precarious balance.