KLUM@GTAP: Spatially-Explicit, Biophysical Land Use in a Computable General Equilibrium Model

Abstract

*Chapter 12 of the forthcoming book "Economic Analysis of Land Use in Global Climate Change Policy," edited by Thomas W. Hertel, Steven Rose, and Richard S.J. Tol. In this paper the global agricultural land use model KLUM is coupled to an extended version of the computable general equilibrium model (CGE) GTAP in order to consistently assess the integrated impacts of climate change on global cropland allocation and its implications for economic development. The methodology is innovative as it introduces dynamic economic land-use decisions based also on the biophysical aspects of land into a state-of the-art CGE; it further allows the projection of resulting changes in cropland patterns at a spatially explicit level. A convergence test and illustrative future simulations underpin the robustness analysis and serve to highlight the potential of the coupled system. Reference simulations with the uncoupled models emphasize the impact and relevance of the coupling; the results of coupled and uncoupled simulations can differ by several hundred percent.