Pope Leo XIV marked the 40th anniversary of the Chernobyl nuclear disaster with a call for atomic energy to be used exclusively for peaceful purposes. Speaking at the Vatican following a prayer service on Sunday, the pontiff described the 1986 explosion at the Soviet-era nuclear plant—now in Ukraine—as a moment that "marked the conscience of humanity" and serves as a lasting warning about the dangers of powerful technologies.

The disaster, considered the worst civilian nuclear accident in history, led to extensive radiation exposure. According to a 2005 United Nations report, approximately 4,000 deaths have been confirmed or projected in the three worst-affected countries, although various organizations have suggested higher figures. The cleanup crew, known as "liquidators," included an estimated 600,000 people who faced high radiation levels.

During his weekly Angelus address, Pope Leo extended his reflections from the anniversary to a broader moral critique. Drawing on a Gospel metaphor of a sheep thief, he highlighted various forms of theft beyond the literal—pointing to consumerism, prejudice, and misguided ideas as examples. He also condemned those who wage wars and exploit the earth's resources, calling them thieves who jeopardize humanity's prospects for peace and stability.

The pontiff expressed hope that wisdom and responsibility would govern decision-making at all levels, ensuring atomic power supports life and peace rather than destruction. His comments come amid ongoing tensions in Ukraine, where concerns persist that the ongoing conflict with Russia might risk further nuclear incidents.

Pope Leo XIV, the first pontiff from the United States, has recently sparked controversy, including criticism from former President Donald Trump, due to his outspoken stance against war and authoritarianism. Alongside his views on nuclear energy and conflict, the pope’s engagement with broader Church issues has attracted attention, particularly regarding the role of women.

Last weekend, Pope Leo met with Sarah Mullally, the newly appointed head of the Church of England and its first female leader. Mullally's visit to Rome marked her first trip abroad since her enthronement last month. Their meeting highlighted contrasting practices between the Catholic Church, which restricts ordained ministry to men, and the Church of England’s inclusion of women in senior clerical roles.

While the Catholic Church has maintained a male-only clergy, Pope Leo’s immediate predecessor, Francis, began appointing women to key administrative Vatican positions. Notably, Sister Simona Brambilla serves as prefect of the Vatican office overseeing Catholic religious orders worldwide, and Sister Raffaella Petrini was named president of the Vatican City governorate in March 2025, representing significant steps toward elevating women's leadership within the Church hierarchy.