Developing a system of National Climate Assessment indicators to track climate change impacts, vulnerabilities, and preparedness
The National Climate Assessment (NCA) is being conducted under the auspices of the U.S. Global Change Research Program (USGCRP), which is required to provide a report to Congress every 4 years. Part of the vision for the NCA process is a system of physical, ecological, and societal indicators that communicate key aspects of the physical climate, climate impacts, vulnerabilities, and preparedness for the purpose of informing both decision makers and the public with scientifically valid information such as the development and implementation of climate adaptation strategies in a particular sector or region. These indicators will be tracked as a part of ongoing assessment activities, with adjustments as necessary to adapt to changing conditions and understanding.
The NCA indicator system will be designed to address questions important to multiple audiences including (but not limited to) non-scientists (e.g., Congress, U.S. citizens, students), resource managers, and state and municipal planners in a conceptually unified framework. The NCA indicator system will include both current indicators and leading indicators. Current indicators describe current status and trends relative to a historical baseline. Leading indicators are used to project changes in important parameters that could result from possible climate changes. The NCA indicators will be scalable, so that they can be presented as a national aggregate, where appropriate, and also provide information for indicators at state, regional, and local scales.
Different components of the end-to-end climate issue are serving as categories within which to organize an end-to-end system of indicators, many of which include components of the carbon cycle: 1) greenhouse gas emissions and sinks, 2) atmospheric composition, 3) physical climate variability and change, 4) sectors and resources of concern, and 5) adaptation and mitigation responses. This framing has advantages for application to decision support systems. It can be used to identify components of the end-to-end climate issue that both decision-makers and researchers are interested in. It is independent of spatial and temporal scales, and therefore allows the indicators themselves to be described at scales that are the most relevant for their intended use and allows for the development of current state, past trend, and leading indicators. This indicator system will include physical, ecological, and societal indicators and include a much more rigorous assessment of multi-stressor impacts and climate preparedness.