La construccion de hibridos globales de ciencia y politica para la resolucion de problemas ambientales. Estudio de la incidencia de la Evaluacion de Ecosistemas del Milenio.

The Millennium Ecosystems Assessment was launched in 2000 to meet the needs of decision-making from knowledge and environmental appraisement, especially to multilateral conventions initiated or reaffirmed during Rio `92. Defined as a process to assemble and critically value selected knowledge to guide policies, they are constituted as hybrid object of science-policy. The Thesis general intention is to contribute to the current debate about this interface in the context of complex environmental problems, due the re-emergency of topics related to the epistemic nature of the advice of science and the democratic nature of the construction of policy. The thesis wants develops the hypothesis that they achieves finally low influence, only when it is considered by participants as legitimate, sound and salient. The test of the incidence is mainly limited to the establishment of the topic in the negotiation agenda and public debate (from evidences and proposals); but without concrete influence on policy design and implementation, neither on its monitoring and evaluation, showing limited capacity to modify interests, objectives and policy definitions of the States.