Science plays a major part in environmental conflict. Now that role is determined by the human actors engaged in the conflict and the legal and institutional constructs that structure discourse. This article begins by tracing the authority invested in science to ideological assumptions about scientific methodology. Then, four common roles for science in environmental conflict (discoverer, mechanism for accountability, shield, and tool for persuasion), are described. These roles are increasingly unproductive in resolving environmental conflict, partly due to the misfit between the actual conduct of science and its ideal. This article proposes that a new role, one that is more consistent with a social constructionist view of science, has been crafted as a byproduct of decision-making innovations that prescribe explicit negotiations among representatives of groups engaged in an environmental dispute. As a tool of facilitation, science may be used more constructively to resolve environmental disputes.