This research project aimed to highlight the relevance of fairness-concepts within the population and to analyze the determinants of voluntary contributions to climate protection, so as to deepen and advance the understanding of successful climate negotiations. This included analyzing the role of acceptance of international climate agreements on the individual level. Thereby, it was of particular interest in how far the interrelation between the population and the participants of climate negotiations influences the success of international climate negotiations. Furthermore, the importance of fairness concepts in the population was analyzed. This also involved questions on the congruency of notions of fairness between the population and the participants of climate negotiations, as well as their influence on the negotiation outcomes. Individual voluntary climate protection mechanisms (e.g., CO2 offsetting activities) were analyzed, particularly with regard to their potential impact on an international climate agreement. Methodologically, the research project combined theoretical, empirical and experimental approaches.