The Catholic Church, the world’s largest religious organization, has actively participated in discussions on environmental protection during the past fifty years. The three most recent popes, John Paul II, Benedict XVI, and Francis, all issued primary teaching documents (encyclicals) on the subject, culminating in “Laudato Si,” the 2015 encyclical by Pope Francis that cemented protection of the environment as a core component of Catholic social teaching. World Youth Day, founded by John Paul II, is the world’s largest religious gathering for young people. World Youth Day edition in Lisbon placed special emphasis on environmental protection. The official program, which consisted of spiritual, historical, and tourist content, gave the pilgrims clear instructions on environmental protection. While many of the tips, such as advice on waste recycling, were met with wide approval, some requirements, which asked for greater sacrifice, met strong resistance. In this paper, we look at the contributions of the Catholic Church and recent popes to contemporary environmental issues. Laudato Si covers many scientific, political, cultural, and theological issues related to the environment. In keeping with his predecessors, Pope Francis emphasized that in addressing such issues, we must realize that everything in the created world is connected, that we must move away from those aspects of the “technological imperative” that tend to dissolve this connectivity and that, as a result, lifestyles (particularly in the developed world) must change. The last injunction is widely shared by those (secular or religious) concerned with environmental protection. However, in keeping with the injunction that “everything is connected,” Francis (as well as John Paul and Benedict) proposed a lifestyle change that is not widely accepted. The dominant feature of Western lifestyles in the past two generations has been individualism, which is characterized by sexual liberation, a decrease in families, and a decline in religion. We greatly privilege this brand of lifestyle liberalism and individualism. Nevertheless, as “Laudato Si” emphasized, its rise has led to interior emptiness and social fragmentation. To compensate, we desire more material things, innovations, and experiences—the desires that feed the dynamics of materialism and consumerism. In Pope’s view, any effective lifestyle change must address the resulting spiritual weakness that denies the ultimate connectivity of all created things. Those concerned with environmentalism, particularly climate change, are happy with Pope’s support. However, are they willing to turn away from these aspects of the modern Western lifestyle that (in concert with other factors) create the consumerist demand that the Pope urges us to abandon? World Youth Day was the first universal event sponsored by the Church, during which we could see Laudato Si in practice. How did it go?