During the George W. Bush administration, politics and ideology routinely trumped scientific knowledge in making environmental policy. Data were falsified, reports were edited selectively, and scientists were censored. The Obama administration has pledged to restore science to the policy making process. And yet, as the authors of Knowledge and Environmental Policy point out, the problems in connecting scientific discovery to science-based policy are systemic. The process -- currently structured in a futile effort to separate policy from science -- is dysfunctional in many respects. William Ascher, Toddi Steelman, and Robert Healy analyze the dysfunction and offer recommendations for incorporating formal science and other important types of knowledge (including local knowledge and public sentiment) into the environmental policymaking process. The authors divide the knowledge process into three functions -- generation, transmission, and use -- and explore the key obstacles to incorporating knowledge into the making of environmental policy. Using case studies and integrating a broad literature on science, politics, and policy, they examine the ignorance or distortion of policy-relevant knowledge, the overemphasis of particular concerns and the neglect of others, and the marginalization of certain voices. The book's analysis will be valuable to scientists who want to make their work more accessible and useful to environmental policy and to policymakers who want their decisions to be informed by science but have had difficulty finding scientific knowledge that is useful or timely.