Scenarios of Change for Sustained Assessment
Scenarios are descriptions of plausible future conditions—either narrative or quantitative—that provide a basis for analyzing potential impacts of and responses to global change. Scenarios are not predictions or forecasts; rather, they are tools to understand how future conditions might evolve under a range of possible decisions. By providing detailed examples of how different factors could change and interact, scenarios constrain uncertainty and offer valuable input for assessments. USGCRP is working toward scenarios of change that can feed into the sustained assessment process and support the needs of scientists and stakeholders.
In June 2014, USGCRP convened two workshops, respectively focused on developing scenarios for changes in U.S. demographics and land use/land cover—both of which have the potential to interact with climate change. These workshops brought together modelers and scenario users to identify critical uncertainties in projections; key natural, socioeconomic, and policy variables to consider; and capabilities (or gaps therein) to produce long-term projections for future research and decisional needs. Resources and presentations from both workshops and a report from the land use/land cover workshop are available online. The demographics workshop report is expected in 2015.
Looking ahead, a NOAA technical report expected in 2015 will compare climate projections for the United States from the third and fifth phases of CMIP, with an in-depth analysis of temperature and precipitation projections from the latter. This report will deliver a suite of climate model datasets that can be leveraged in the development of scenarios for the next quadrennial National Climate Assessment. In addition, USGCRP recently convened a workshop to facilitate interagency dialogue around the subject of downscaled climate projections; this workshop served as an early step in a broader suite of planned activities that will collectively inform future assessments and provide a focal point for technical expertise on climate projections.
Land cover change, such as the rapid urban expansion of Las Vegas shown above (left: 1992; right: 2013), interacts with climate change in complex ways. Scenarios can be used to understand and plan for the plausible permutations of these and other interacting processes in the Earth system. (Source: USGS Landsat)