Assessing the vulnerability of human populations to global environmental change, particularly climate change, is now the main imperative of research and international action. This book seeks to make interpretation of vulnerability research informative to decision and policy making and to bridge the gap between knowledge created by researchers and what is required by decision makers.It discusses vulnerability as the central theme and brings together many different applications from disaster studies, climate change impact studies and several other fields. The book provides the most comprehensive synthesis of definitions, theories, formalization and applications, illustrated with examples from different disciplines, regions and periods and from local through to regional, national and international levels. The book concludes with a unifying framework for analyzing integrated methodologies of vulnerability assessment and guiding how research and policy can be linked to reduce vulnerability.