Churches have always been good at naming days and weeks. We need to think only of Christmas and Easter, Advent and Lent, and saints’ feast days by the dozen. So it did not make the news when Pope Francis added another day to the calendar. So when Pope Francis made September 1 an annual day to pray for the care of creation, no one blinked.

But his reasons for doing this don’t simply have to do with internal church business. The day expresses his conviction that the world faces an environmental crisis, and that to address it is a matter of faith. It is not only a political and economic matter that can be left to politicians to decide.

To name the day on September 1 is also significant. Characteristic of Pope Francis it takes him outside the Catholic Church. He has thrown the weight of his own church behind the Orthodox Ecumenical Patriarch Bartholomew, a prominent environmental advocate, who had previously consecrated the day to the Environment.

The naming of the day should be seen as part of a larger strategy that began with the publication of the Encyclical Letter Laudato Si, which addressed the environmental crisis and its roots. Encyclicals can be dismissed as passing events that represent the quirky vision of particular popes. Pope Francis wants the urgency and theological depth which he addresses the environmental crisis to be reflected enduringly in the prayer and reflection of Christians. The day of prayer is a building block in that project.

It also marks the beginning of a month of public appearances when he will be able to address the world. On September 24 he will address a Joint Sitting of the Houses of Congress in the United States. Among other topics, he can be expected to reiterate the weight that the Catholic Church places on action to address climate change.

On the following day he will address the United Nations General Assembly, and be able again to draw attention to the environmental crisis and the right responses to it. On October 4, the feast of St Francis of Assisi, who has inspired his concern for the natural world, he will celebrate the opening Mass for the Synod of Bishops, another event that will draw great media attention.

Through his speeches and meetings Pope Francis can help shape the atmosphere for the Paris governmental conference on climate change. At this very important December meeting in Paris, nations will be expected to nominate a target by which they will reduce emissions, and to move towards a global agreement. The results of previous meetings have been disappointing because governments have been reluctant to pledge themselves to an agreement of which other nations will not be part or will not adhere to.

The Pope’s contribution to the world’s response to the environmental crisis will not lie in his technical knowledge, but in his sense of urgency in his conviction that care for the environment is a spiritual and a religious call. He wants Christians to wonder at our world, to show deep respect in their dealings with it, and to change their ways of living so that they embody respect.

Nominating September 1 as a day of Catholic prayer for the care of creation is a tiny step for humankind. But it is a tile laid in a mosaic on which the future of our world depends.