FAO’s Climate Impact Team has been developing an integrated toolbox to assess the impact of climate change on agriculture. The resulting analysis will support decision making at the national level. This toolbox has a series of components which can be used to carry out each step of impact assessment including producing different climate scenarios, downscaling and economic impact analysis. The four main components of the climate change impact methodology are: a statistical downscaling method for processing GCM (Global Circulation Models) output data; a hydrological model for estimating water resources for irrigation; a crop growth model to simulate future crop yields; and a CGE (Computable General Equilibrium) model for assessing the effect of changing yields on national economies. The toolbox also contains documentation on methods and tools, user manuals and sample data for training purposes.