Developing Scenarios of Change
Scenarios are plausible alternative futures, each describing what might happen under a range of possible assumptions about policy decisions and the behavior of the Earth system. By illustrating possible future conditions, scenarios provide a basis for analyzing the potential impacts of and responses to
Population, demographics, and land-use change: Changes in future population and
Sea-level rise: In 2015, at the request of the White House Council on Climate
Climate change: In May 2015, USGCRP released a memo entitled “U.S. Global Change Research Program General Decisions Regarding Climate-Related Scenarios for Framing NCA4”, signaling to the climate change and impacts scientific communities that NCA4 would base its climate scenario development on the IPCC Representative Concentration Pathways and Coupled Model Intercomparison Project Phase 5 ensemble of model runs. Subsequently, USGCRP is developing and implementing an overall strategy for developing authoritative, relevant, and accessible climate-change scenarios for NCA4 and the Sustained Assessment. Participating agencies include NASA, NOAA, DOE, the Bureau of Reclamation, USGS, U.S. Army Corps of Engineers, EPA, and the Office of Science and Technology Policy.
These efforts are focused on the development of scenario products, and accompanying guidance, for NCA4 author teams and for Federal, state, tribal, and local users in need of scenarios to support their planning and decision making. Scenarios are based on aspects of the U.S. climate most relevant for assessing key societal risks, such as changes in the frequency and intensity of weather and climate extremes, and attempt to characterize these risk-relevant climate changes in the face of current scientific uncertainties.