Polycentric Integrated Assessment

摘要

Transitions towards sustainability will require major changes in today's socio-economic systems. Such changes cannot be brought about by con-ventional policy measures. We advocate a new approach of a polycentric understanding of policy making that invokes instances of social learning at different levels of societal organization. The notion of polycentric involves the integration of different levels of human choice and geographical domains. The spatial component involves the sequence local - regional - national - global. It involves the combination of different types of human choice at different levels of societal organization (e.g., legal regulations, taxes, sub-sidies, local initiatives). Trying to understand what is the impact of dealing with diverse "global change phenomena" at diverse levels of organization will require new approaches to deal with human agency. Agent based modeling and its application in participatory settings is a novel promising approach to deal with such choice problems. The importance of such scaling issues are explored for the problem of climate change and water resource management. Whereas water issues have primarily been approached from a regional, even local perspective, the climate problem has been addressed in the first place at the global scale with a global scientific and policy process (IPCC, Kyoto protocol). Regarding climate change one has increasingly recognized the importance of addressing the topic at the regional scale. Most choices will be made at the regional scale and will invoke short-term decisions that are not directly related to climate change. Regarding water resource management patterns of regional water scarcity may be compensated by complementary patterns of food trade leading to major transfers of virtual water at the global scale. In both cases the coupling of different scales in space, organization and time poses major challenges for integrated assessment.