Sedimentation–upwelling: a model for the science–policy interface in the case of climate change and California water

This paper sets forth a framework to describe the science–policy interface. The “sedimentation–upwelling model” is a two-part process through which scientific information gradually becomes part of resource managers' and policymakers' agendas. In this paper, sedimentation refers to a gradual process through which scientific information slowly permeates a policymaking body, often slowly and through multiple sources. Upwelling is a process by which policymakers, having become aware of scientific concepts in a general way though sedimentation, independently devise policy actions consistent with the scientific body of knowledge. The framework was tested in the case of climate change science and California water policy through an analysis of historical data and interviews with key players on the science and policy sides of this issue. A remarkably consistent scientific message over the course of fifteen years before 2003 was not followed by corresponding changes in water management, as a “linear model” in which policymakers act directly on scientists recommendations would predict. Instead, both sedimentation and upwelling operated in this case and the importance of the linear pathway was minimal. Viewing science in the context of the upwelling-sedimentation model does not imply that science is ultimately any less influential on policy. On the contrary, this work suggests that policymakers rely on general, widespread cues that come both directly from scientists and through intermediaries and that these cues can influence policy choices in important, but often indirect ways.