Effective climate clubs require ambition, leverage and insulation: Theorizing issue linkage in climate change and trade

Many proposals advocate linking climate and trade policy to improve climate cooperation. Since climate mitigation is non-excludable, mitigation cannot be enforced through issue-specific reciprocity, but linking mitigation with trade penalties on non-participants could incorporate trade’s enforcement powers into a climate club. However, this perspective has overlooked the relationship between climate policy preferences and existing trade flows. Using a model of issue linkage in climate and trade motivated by findings from the domestic political economy of international trade, I show that the necessary conditions for climate clubs are exacting. Effective climate–trade clubs require members with high levels of climate policy ambition, export leverage over laggards, and insulation from trade retaliation. However, I show that these three attributes do not necessarily co-occur theoretically or empirically. States that support the club’s goals on one dimension may undermine them on another. The findings provide insights into institutional design, climate politics, and the constraints on issue linkage in international cooperation.