A highly anticipated event is taking place for many Christians in France with the visit of Pope Leo XIV, scheduled from September 25 to 28. This visit is expected to bring together thousands of followers and highlight the Catholic Church's ongoing engagement with social and environmental issues. As part of this visit, a central question will be explored: does an ecological sin exist? The concept of an ecological sin is not traditionally found in Catholic doctrine, but it has become a growing topic of discussion among theologians and environmentalists. Some argue that actions harming the environment—such as pollution, deforestation, or excessive resource consumption—can be seen as moral failings, especially when they disproportionately affect the poor or future generations. Others maintain that the Church has not formally recognized such actions as sins, but rather as issues requiring ethical reflection and action. In recent years, the Catholic Church has increasingly emphasized the importance of environmental stewardship. Pope Francis, for example, has spoken extensively on the need to care for creation, as highlighted in his encyclical Laudato Si’. While Pope Leo XIV has not yet made similar statements, his visit offers an opportunity to explore how the Church views its role in addressing global environmental challenges. This visit also provides a chance for the French Catholic community to reflect on how their faith informs their relationship with the natural world. Whether or not an ecological sin is formally recognized, the discussion surrounding it underscores the growing intersection between religion, ethics, and environmental responsibility.