An apostolic exhortation to all people of good will on the climate crisis, published on the memorial of Saint Francis of Assisi eight years after Laudato Si' and addressed to the situation in the run-up to the COP28 conference in Dubai. It reviews the state of the global climate and answers common objections, criticises the technocratic paradigm and the illusion of unlimited human power, calls for effective and binding multilateralism reformed 'from below', assesses the record of the climate conferences, and closes with spiritual motivations drawn from Scripture and from the Christian understanding of the human person within, not above, creation.