The Ag-GRID Global Gridded Crop Model Intercomparison (GGCMI).

In 2012 AgMIP led a Global Gridded Crop Model (GGCM) Intercomparison fast-track project in coordination with the PIK-led Inter-Sectoral Impacts Model Intercomparison Project (ISI-MIP). This fast-track included 7 GGCMs and updated the state of knowledge on climate change vulnerabilities and impacts using modern global high-resolution models driven by climate model output from CMIP5. This fast-track culminated with the January 31^st submission of 6 papers to a PNAS special issue. Initial results indicate the potential of global gridded crop model simulations and the need to further improve understanding of mechanisms, assumptions, and uncertainties of model design and execution; these are best addressed in a coordinated model intercomparison project at continental and global scale.

Starting in Spring 2013, we are developing a new set of protocols for the next phase of the GGCMI, which will focus on model evaluation, skill, and improvement. Phase II already includes 14 modeling groups from 8 countries. It will run for 3 years and include 3 overlapping stages of increasing duration: 1) historical simulation and model evaluation, 2) analysis of model sensitivity to CTWN (carbon, temperature, water, and nitrogen), and 3) a new coordinated regional and global climate assessment. 

In this session we present results from the completed fast-track as well as preliminary validation results from stage 1 of the GGCMI.