MODELING LAND-USE CHANGE IMPACTS OF BIOFUELS IN THE GTAP-BIO FRAMEWORK

This paper reviews an analysis of land use change impacts of expanded biofuel production with GTAP-BIO computable general equilibrium (CGE) model. It describes the treatment of energy substitution, the role of biofuel by-products, specification of bilateral trade, the determination of land cover changes in response to increased biofuel feedstock production, and changes in crop yields – both at the intensive and extensive margins. The paper responds to some of the criticisms of GTAP-BIO and provides insights into the sensitivity of land use change and GHG emissions to changes in key parameters and assumptions. In particular, it considers an alternative specification of acreage response that takes into account the degree of land heterogeneity within agro-ecological zone (AEZ) for different AEZs and countries. The paper concludes with the discussion of alternative specifications of land mobility across uses employed in CGE models and the agenda for further research to narrow parametric and structural uncertainty to improve the model's performance.