The concepts of vulnerability, resilience and adaptation (VRA) are interrelated and have wide application to global change science. Events during the last years, such as the hurricane Katrina, the Southeast Asian tsunami, and the Pakistan earthquake, together with the bird flu and continuing droughts in Africa, dramatically illustrate the potential vulnerability of human society to disturbances and variability and VRA are used to analyze these and similar events. Furthermore, understanding VRA, as related to the socio-ecological system, is particularly important given that identifying future trajectories and behavioural changes in the Earth System depends on understanding the dynamic interplay between social and ecological components, as many issues related to VRA fall within this category.

    Vulnerability is defined in different ways, depending on different research traditions, yet is most often conceptualized as being constituted by components that include exposure to perturbations or external stresses, sensitivity to perturbation, and the capacity to adapt. Generally speaking, it includes the attributes of persons or groups that enable them to cope with the impact of disturbances, like natural hazards.

    Resilience originated as a core concept within ecology and is used by ecologists in their analysis of population ecology of plants and animals and in the study of managing ecosystems. Since the late 1980s, the concept has increasingly been used in the analysis of human–environment interactions, mainly to describe and understand how humans affect the resilience of ecosystems. The term can be further applied within the social context as the ability of groups or communities to cope with external stresses and disturbances as a result of social, political, and environmental change.

    Adaptation to environmental variability has been a focus of anthropologists since the early 1900s. In the 1990s, scholars began to use the term adaptation for the study of the consequences of human-induced climatic change, without explicitly relating this back to the conceptual origins in anthropology. Adaptation is generally perceived to include an adjustment in social-ecological systems in response to actual, perceived, or expected environmental changes and their impacts.

Ultimately, vulnerability, resilience, and adaptation are different manifestations of more general processes of response to changes in the relationship between open dynamical systems and their external environment.