Political institutions are keen to use the best available scientific knowledge in decision-making. For environmental policy, relevant scientific evidence can be complex and extensive, so expert judgment is frequently relied upon, without clear links to the evidence itself. We propose a new transparent process for incorporating research evidence into policy decisions, involving independent synopsis of evidence relating to all possible policy options combined with expert evaluation of what the evidence means for specific policy questions. We illustrate the process using reforms of the European Union's Common Agricultural Policy currently being negotiated. Under the reform proposals, 30% of direct payments to farmers will become conditional upon three “compulsory greening measures.” Independently, we compiled and evaluated experimental evidence for the effects of 85 interventions to protect wildlife on northern European farmland, 12 of which correspond to aspects of the compulsory greening measures. Our evaluation clearly indicates evidence of consistent wildlife benefits for some, but not all, of the greening measures. The process of evidence synopsis with expert evaluation has three advantages over existing efforts to incorporate evidence into policy decisions: it provides a clear evidence audit trail, allows rapid response to new policy contexts, and clarifies sources of uncertainty.