“Intelligent Ensemble” Projections of Precipitation and Surface Radiation in support of Agricultural Climate Change Adaptation

. Earth’s climate is changing and will continue to change into the foreseeable future. Expected changes in the climatological distribution of precipitation, surface temperature, and surface solar radiation will significantly impact agriculture. Adaptation strategies are, therefore, required to reduce the agricultural impacts of climate change. Climate change projections of precipitation, surface temperature, and surface solar radiation distributions are necessary input for adaption planning studies. These projections are conventionally constructed from an ensemble of climate model simulations (e.g., the Coupled Model Intercomparison Project 5 (CMIP5)) as an equal-weight average—one model one vote. Each climate model, however, represents the array of climate-relevant physical processes with varying degrees of fidelity influencing the projection of individual climate variables differently. Presented here is a new approach—termed the “Intelligent Ensemble” method—that constructs climate variable projections by weighting each model according to its ability to represent key physical processes—e.g., precipitation probability distribution. This approach provides added value over the conventional equal-weight average method. Physical process metrics applied in the “Intelligent Ensemble” method are created using a combination of NASA and NOAA satellite and surface-based cloud, radiation, temperature, and precipitation data sets. The “Intelligent Ensemble” method is applied to the RCP4.5 and RCP8.5 anthropogenic climate forcing simulations within the CMIP5 archive to develop a set of climate change scenarios for precipitation, temperature, and surface solar radiation in each region defined within the 2014 National Climate Assessment for use in climate change adaptation studies.