Are we using the right climate? Developing ecosystem-based climatologies to inform impact assessments

Most living organisms thrive under a certain set of environmental conditions and behaviors, and are negatively affected by others. The resilience of an ecosystem to climate change is a function of the conditions (e.g., average, variability, and extremes) to which it has become adapted. Therefore a useful climatic baseline is one that describes those accustomed conditions. However, climatologies of environmental elements generally do not take ecological relevance into account, preferring instead to rely on arbitrary time frames (e.g., 30-year normals). While such periodic climatologies have application to evaluating climate changes, they are limited in their capacity to address impacts from those changes. As a result, valuable comparative and analytical information is lost before an impact assessment even begins. This paper discusses the development of ecosystem-based climatologies, and how climatologies derived from periods of optimal ecosystem health can greatly improve our ability to establish an ecologically meaningful climate baseline for use in impact assessments. Examples are provided from the Florida Keys coral reef ecosystem.