The purpose of the GEO Resource Book is to help build capacity for forward- looking integrated environmental assessment (IEA) and reporting at the sub-global level. For the purposes of this publication, we define IEA as the process of producing and communicating future-oriented, policy relevant information on key interactions between the natural environment and human society. The methodology underlying IEA has been pioneered and championed by the Global Environmental Outlook, UNEP’s flagship assessment on the status and direction of the global environment.