The Global Deserts Outlook, launched on 5 June 2006, during the World Environment Day, is the first thematic report in the Global Environment Outlook (GEO) series of environmental assessments by the United Nations Environment Programme (UNEP). This GEO report, prepared by experts from across the globe, traces the history and astonishing biology of the deserts and assesses likely future changes. Chapter 4 on the ‘State and Trends of the World’s Deserts’ analyzes trends in land use and land degradation in deserts, impact of land degradation and responses, among other topics.