Environmental protection, climate justice, and the transition to ecologically responsible forms of human civilizations have become a global priority for the whole of humanity. Several regional ecumenical organizations, National Councils of Churches, and members of both the World Council of Churches (WCC) and Action of Churches Together (ACT Alliance) have taken a pioneering role in bringing forward and sustaining imperatives related to climate resilience, environmental stewardship, and ecological consciousness on the international agenda. Churches, faith actors, and civil society organizations more strongly than ever before are stating that there are limits to the commercialization, financialization, and exploitation of nature, natural resources, and indigenous people on this earth. There is growing recognition that continued destruction of natural habitats will destroy the sensitive interactive systems among plants, animals, fungi, and fish on earth, thereby threatening the survival of all. The vast contextual theological work, advocacy efforts, and practical as well as educational projects from churches in the global South in the area of eco-theologies, creation care, climate justice, and ethics of sustainability are still less known and less visible. This provided motivation for this International Handbook on Creation Care and Eco-Diakonia to be prepared for the WCC assembly in Karlsruhe, Germany, in September 2022 in collaboration with the All African Conference of Christian Churches, Christian Conference of Churches in Asia, United Evangelical Mission, the International Communion of Churches in Three Continents, and ecumenical think tanks in Latin America.