During the first joint meeting, which took place on 5 July 2019 at ZEW in Mannheim, the members of the advisory board were informed about the current status of the work packages as well as the planned research projects. After a general overview by the project coordinator, Andreas Ziegler, representatives of the project partners presented previous activities (i.e. a policy session on non-state actors‘ activities in climate protection at an international conference of environmental economists and a research project in cooperation with church actors). After that, the research ideas and planned research projects, which will investigate the relevance of non-state actors such as municipalities, companies or municipalities for individual climate protection activities and climate policy, were presented and discussed. These presentations were used to develop a common understanding of the individual actors and their roles, which is decisive for the further course of the project. In addition, the research ideas were discussed against the background of practical experience, further developed and concretized. Of particular importance are the institutional knowledge and the observation of concrete activities in the field of climate protection under real conditions. The cooperation will be continued in smaller groups and supplemented by two further joint workshops in the course of the project.