The computable general equilibrium REFORM model of the Danish economy developed by the Danish Institute for Economic Modelling and Forecasting (DREAM) is currently used by the Danish Ministry of Finance and the Danish Economic Councils to evaluate the long-run effects of policies aimed at improving the performance of the Danish economy. Drawing on the expertise of the DREAM group, the Ministry of Finance plans to build a new macroeconomic model for Denmark. The long run equilibrium of this model is based on the same data and theory as the REFORM model. We propose to construct the GREEN REFORM model as a direct extension of the REFORM model. The GREEN REFORM model will be able to simulate the environmental effects of Danish economic activity and the economic effects of policy interventions to meet the targets for Danish environmental, energy and climate policy.