The AgMIP Coordinated Climate-Crop Modeling Project (C3MP): Methods and Protocols

Climate change is expected to alter a multitude of factors important to agricultural systems, including pests, diseases, weeds, extreme climate events, water resources, soil degradation, and socio-economic pressures. Changes to carbon dioxide concentration ([CO2]), temperature, andwater (CTW) will be the primary drivers of change in cropgrowth and agricultural systems. Therefore, establishing the CTW-change sensitivity of cropyields is an urgent research need and warrants diverse methods of investigation. Cropmodels provide a biophysical, process-based tool to investigate cropresponses across varying environmental conditions and farm management techniques, and have been applied in climate impact assessmentby using a variety of methods (White et al., 2011, and references therein). However, there is a significant amount of divergence between various cropmodels’ responses to CTW changes (R¨ otteret al., 2011). While the application of a site-based cropmodel is relatively simple, the coordination of such agricultural impact assessmentson larger scales requires consistent and timely contributions from a large number of cropmodelers, each time a new global climate model (GCM) scenario or downscalingtechnique is created. A coordinated, global effort to rapidly examine CTW sensitivity across multiple crops, cropmodels, and sites is needed to aid model development and enhance the assessment of climate impacts (Deser et al., 2012)...