The concept of essential climate variables in support of climate research, applications, and policy

The concept of Essential Climate Variables (ECV) developed under the Global Climate Observing System (GCOS) for a range of applications is discussed, as well as an empirical basis for understanding past, current, and possible future climate variability and change is proposed. The ECV concept is flexible with changing priorities, application needs, and scientific and technological innovation. Priorities remain essential; the ECV concept has provided guidance in this regard. It may serve as a blueprint for communities of practice in other societal benefit areas of the GEOSS as they assess evolving data needs and required actions for observing the Earth system. The essential character of the ECV list has been one of its strengths, calling for prudence in its expansion. The ECV concept has proven useful to scientists, observing system operators, program planners, and policymakers, but issues related to consistency, data curation, resources, requirements, and review of the ECV concept have been identified.