Although in recent years great emphasis has been placed on global agreements and national commitments on climate change, ultimately action on mitigation and adaptation must take place at the local level. Many local authorities have to face questions of whether they should develop policies on climate change, and if so, on what evidence should policies be designed and delivered. This paper describes how academic research on the economics of low carbon cities (the ‘mini-Stern review’) helped create such an evidence base for the Leeds City Region and its constituent local authorities. We describe how the response to the evidence and the pathways to impact were different in the individual local authorities and what this means for our understanding of evidence in local policy making. In terms of Weiss’ (Social sciences and modern states: national experiences and theoretical crossroads. Advances in political science, Cambridge University Press, Cambridge, 1991) classification, the study was mainly useful as an argument and idea rather than being used instrumentally. We find that the policy and political context in each authority determines to a large extent whether such an academic study is useable as evidence. The contents and timing of the study need to align with existing policy and/or political agendas: is climate change on the agenda at all, with what priority and how is it framed. We find confirmation of a relationship between the policy problem type and the role of evidence as argument, idea or data. The mini-Stern study itself was just one contribution to wide-ranging processes of informing, convincing, pressurising, etc., not just within the different councils but also within the wider communities. Other contextual factors include composition, agenda and activities of local civil society and the local business community. Finally, it depends on the expertise of policy officers in the councils what use is made of evidence. Making policy takes (much) time, translation and negotiation across levels and sectors. Policy work describes how policy officers bring their diverse forms of knowledge to bear on policy questions; how this work is done is something that is learned from practice rather than from the study.