International discussions regarding the environment have too narrowly focused on contributions by secular actors. The Catholic Church, recognized for its influential role in the democratization processes of the 1990s, also has a long-standing position regarding climate change, yet remains understudied. How can the Church contribute to the international community's debates regarding the environment and climate change? Using the framework of constructivism and Jurgen Habermas' concept of institutional translation, I argue that the Church is a norm entrepreneur that promotes a foreign policy of human/integral ecology. The most recent articulation of this foreign policy is Pope Francis' encyclical Laudato Si’, which was referenced by the Holy See at the 26th UN Climate Change Conference (COP26) in 2021. The Church's participation at COP26 was the latest animation and application of the Church's foreign policy; I examine the Church's efforts to change the narrative on the environment toward a shared, global responsibility.