The requirement of bottom-up action from all the countries to deal with climate change makes it necessary to analyze the factors influencing policy adoption. This article contributes to the policy literature by shedding light on the conditions, which incentivize countries to adopt more climate mitigation policies. The theoretical argument builds on the integrated approaches to study policy diffusion, which include both internal and external determinants as explanations for the adoption of policies. While previous applications typically operationalize the latter by regional proximity, this study highlights the added value of network dependencies capturing political and cooperative interactions across countries. The article finds that the adoption of climate policies is a matter of social influence. Countries are more likely to adopt policies if they cooperate with countries that have adopted more climate policies and are in a similar structural position to countries that are active in climate protection. This article not only is an important theoretical contribution to the policy literature but also enriches our methodological and empirical understanding of climate policy diffusion.