Vulnerability in the context of sustainability refers to the degree to which, and reasons why a community may be vulnerable to perturbations that may compromise its long-term sustainability. In this way, vulnerability is related to resiliency – the degree to which a community may resist and/or recover from a disturbance. Vulnerability is often discussed in the context of “vulnerability assessments,” which typically involve identifying, quantifying, and perhaps ranking risks. Assessments may further prioritize strategies for preparing for the various risks. Risks may be tied to external influences, such as rising seas, or due to weaknesses within the community’s internal defenses. An example of a vulnerable community might be a coastal community that will likely lose its freshwater aquifer as sea-level rises and may not have the capacity to properly or quickly develop coping mechanisms.