ABSTRACT
This case study examines dryland degradation as an international problem. It maintains that land degradation assessment should include economic, social, ecological, and political factors. A detailed discussion is presented of the work carried out by the United Nations Environment Programme (UNEP) to assess the global costs of desertification, and the limitations of the UNEP approach are outlined. The use of global models is then explained. A brief description of the SARUM-AREAM global model is provided, including extensions of the model to study the effects of economic policies in developed countries on gross output, land use and land condition in Africa. The policies simulated include trade liberalization, trade restrictions, and trade preferences for African food exports, as well as various kinds of development assistance programmes. Sample results are presented. The modelis at the pilot stage, and information generated is essentially qualitative. Further work will be required to improve the empirical foundations of the model before it is used for quantitative analysis.
