Co-benefits motivate individual donations to mitigate climate change

We study the role of co-benefits – positive effects of climate protection projects in addition to CO2 reduction – for the motivation to contribute to climate change mitigation. In two artefactual field experiments conducted with large population samples from Germany (n = 2,400 in total), we test if and how the existence and specific nature of co-benefits affect donations. In both experiments, we find that co-benefits have a positive impact on contributions to climate protection. Our second experiment shows that contributions also respond to the nature of co-benefits, and these responses seem to be driven by individual donor preferences for the respective type of co-benefit. Moreover, we observe that making carbon footprints and thus individual responsibility for environmental externalities more salient increases donations irrespective of the existence and nature of co-benefits. Finally, when uncertainty about co-benefits is introduced, the majority of potential donors requests information in both experiments, and those who choose to be informed about co-benefits provide higher donations relative to subjects who choose not to be informed.