Pope Francis encourages members of many religions to work together to care for the Earth

People hold a banner reading ' Climate action Now ' in St. Peter's Square, at the Vatican, Sunday, June 28, 2015. Greeting people Sunday from his studio window, Francis praised a few hundred people who marched to St. Peter's Square under the banner "one Earth, one family." Marchers included Christians, Muslims, Jews, Hindus and others. Their route began near the French embassy to remind people of a climate change conference in Paris later this year. (AP Photo/Andrew Medichini) (The Associated Press)

People hold banners reading ' Climate action Now ' and ' Many Faiths, One Planet ' in St. Peter's Square, at the Vatican, Sunday, June 28, 2015. Greeting people Sunday from his studio window, Francis praised a few hundred people who marched to St. Peter's Square under the banner "one Earth, one family." Marchers included Christians, Muslims, Jews, Hindus and others. Their route began near the French embassy to remind people of a climate change conference in Paris later this year. (AP Photo/Andrew Medichini) (The Associated Press)

People hold banners reading ' Climate action Now ' and ' Many Faiths, One Planet ' in St. Peter's Square, at the Vatican, Sunday, June 28, 2015. Greeting people Sunday from his studio window, Francis praised a few hundred people who marched to St. Peter's Square under the banner "one Earth, one family." Marchers included Christians, Muslims, Jews, Hindus and others. Their route began near the French embassy to remind people of a climate change conference in Paris later this year. (AP Photo/Andrew Medichini) (The Associated Press)

Pope Francis is encouraging people of different religions to work together to care for the Earth, which he calls our "common house."

Greeting people Sunday from his studio window, Francis praised a few hundred people who marched to St. Peter's Square under the banner "One Earth, one family."

Marchers included Christians, Muslims, Jews, Hindus and others. Their route began near the French embassy to remind people of an important climate change conference in Paris in December.

Francis said "I encourage the collaboration between persons and associations of different religions on behalf of an integral ecology." He offered good wishes to young people who are discussing "the care of the common house."

In a recent encyclical, or teaching document, Francis wrote passionately about the world's moral duty to save the Earth.