In a new document titled “Laudate Deum,” or “Praise God,” the head of the Catholic Church issued his strongest warning yet that action is needed to alleviate suffering.

Pope Francis made his strongest statements yet about climate change Wednesday, rebuking fossil fuel companies and urging countries to make an immediate transition to renewable energy.

In a new document titled “Laudate Deum,” or “Praise God,” the pope criticizes oil and gas companies for greenwashing new fossil fuel projects and calls for more ambitious efforts in the West to tackle the climate crisis. In the landmark apostolic exhortation, a form of papal writing, Francis says that “avoiding an increase of a tenth of a degree in the global temperature would already suffice to alleviate some suffering for many people.”

“Laudate Deum” is a follow-up to the pope’s 2015 encyclical on climate change, known as “Laudato Si’,” which lamented the exploitation of the planet and cast the protection of the environment as a moral imperative. When it was released, “Laudato Si’” was viewed as an extraordinary move by the head of the Catholic Church to address global warming and its consequences.

Nearly a decade later, the pope’s message has taken on new urgency.