Green electoral performance and national climate change commitment: The conditional effect of EU membership

Does Green party electoral success lead to increased climate change commitment, and if so how? Drawing on a new OECD database on climate change outlays, we probe indirect influence from Green electoral success as mediated by inter-party competition, and direct mechanisms of influence from elected Green representatives. Our headline finding is that EU membership functions as a contextual catalyst for inter-party competition, with EU governing parties responding to Greens’ strong electoral performance by increasing climate change outlays to appeal to environmentally motivated voters. We also find evidence that, both across the OECD cohort and the EU sub-grouping, Green coalition presence is associated with increased climate spending over a political cycle. While direct Green influence through coalition presence is widespread, indirect influence mediated by inter-party competition is conditional on EU membership. Findings fit with literature highlighting systematic difference between EU members’ climate performance, and that of other advanced-industrialised states.