1 Science for the 21st century: from social contract to the scientific core

The article addresses the need, posed by the challenges of sustainable development and the changing context at the beginning of the 21st century, for changes in the method and practice of science. The major challenges for a “sustainability science ” arise from increasing complexification at the ontological, epistemological and political levels, calling for an integrated science going far beyond an interdisciplinary style of research. The requirement is for the development, adoption, and dissemination of a truly complex-systems scientific research model. Complex socio-ecological systems share a number of fundamental properties that require changes in scientific methods, criteria of truth and quality, and conceptual frameworks. These properties include non-linearity, plurality of perspectives, emergence of properties, self-organization, multiplicity of scales, and irreducible uncertainty. Some implications of the analysis are pointed out, in the form of practical recommendations. The authors argue for the involvement of both natural and social scientists in the investigation of the necessary steps to develop a sustainability science