What is driving changes to the sustainability of mountain communities in the Hindu Kush Himalaya (HKH)? This chapter seeks answers to this question. Divided into three main sections, it documents the evidence on three types of change—environmental, social, and economic— that reflect the three pillars of sustainability defined by Agenda 21 of the United Nations. As each section explores one of these types of change to sustainability, it describes trends, identifies existing and potential impacts, and relates the change to a varied and often complicated set of drivers.
