We share a future of environmental changes that entails different consequences for people and regions. Vulnerability, a central concept in understanding these distributions is receiving increasing attention, although little consensus exists about its meaning and implications. An overview of the definitions, factors and explanations of vulnerability raises issues of values and policy converging around vulnerability. Four issues are discussed in greater detail: (1) the relationship between dimensions of vulnerability (exposure, resistance, the ability to resist harm, and resilience, the capacity to recover from impacts); (2) the relationship between biophysical and social distributions of vulnerability; (3) the emergence of vulnerability as a characteristic of relationships across social scales; and (4) the role of temporal sequences or cycles in creating ‘windows of vulnerability.’