Christians have an important role to play in helping people have a change of heart and mind regarding responsible protection of the earth, Pope Francis said Friday.

Actions which support the future of the planet "presuppose a transformation on a deeper level, namely a change of hearts and minds," the pope said July 6. "The religions, and the Christian Churches in particular, have a key role to play."

Quoting a Jan. 17, 2001 catechesis from St. Pope John Paul II, he said: "We must encourage and support an 'ecological conversion.'"

Pope Francis spoke to around 300 participants in a July 5-6 international conference called "Saving our Common Home and the Future of Life on Earth," held for the third anniversary of the publication of Pope Francis' environmental encyclical, Laudato Si.

Pointing to St. Francis of Assisi as an inspiration and guide, he prayed using words from Laudato Si, that "our struggles and our concern for this planet never take away the joy of our hope."

"After all, that hope is based on our faith in the power of our heavenly Father," he said.

"We can think back," he continued, "on the call that Francis of Assisi received from the Lord in the little church of San Damiano: 'Go and repair my house, which, as you can see, lies in ruins.' Today, the 'common home' of our planet also needs urgently to be repaired and secured for a sustainable future."

Francis said the subjects of the two upcoming synods – young people and indigenous people, especially those from the Amazon region – should be at the forefront of a Catholic's commitment to the common home.

Young people will "face the consequences of the current environmental and climate crisis," he said, and "consequently, intergenerational solidarity 'is not optional, but rather a basic question of justice, since the world we have received also belongs to those who will follow us' (Laudato Si 159)."

Catholics can learn a lot from indigenous people and their love for the land, the pope said, noting his grief at seeing the lands of indigenous people taken "and their cultures trampled on by predatory schemes and by new forms of colonialism, fueled by the culture of waste and consumerism."

He explained that indigenous communities treat the land like a gift from God and their ancestors, rather than like a commodity, and that this is something everyone can learn from.

He also expressed hope that states, local authorities, civil society, and economic and religious institutions will "promote the culture and practice of an integral ecology," voicing his support for initiatives such as the upcoming COP24 Summit, which will be held in Poland in December 2018.

Referencing the 2015 Paris Agreement, which the United States controversially withdrew from last year, Francis stated that governments "should strive to honor the commitments" made in the agreement and to avoid creating worse consequences, especially those countries which are "more powerful and pollute the most."

Quoting Laudato Si, the pope said that God, "who calls us to generous commitment and to give him our all, offers us the light and the strength needed to continue on our way."

"He does not abandon us, he does not leave us alone, for he has united himself definitively to our earth, and his love constantly impels us to find new ways forward. Praise be to him!"