Pope Francis on Saturday in Assisi, Italy. Associated Press

ASSISI, Italy — Pope Francis, visiting Assisi, the birthplace of his namesake saint who was close to nature, called on Saturday for “courage” in abandoning fossil fuels and lamented that older generations didn’t know how to protect the planet and secure peace,

He told young people he was pinning his hopes on their efforts in working to save the planet and to make the world’s economy more attentive to the poor.

During his brief visit Saturday to the hill town in central Italy, Francis spoke to a gathering of some 1,000 young people, some of them economists. Others are involved in efforts including startups, focused on helping the environment.

The participants came from all over the world. Among them was a woman who recounted to the pope how she and her husband were helped to flee Afghanistan after the takeover of the Taliban last year by an organization called The Economy of Francis, which is inspired by the life of St. Francis, with his attention to the poor and others in need.

The pope said a world economy is needed that expresses “a new vision of the environment and the Earth.”

“There are many people, businesses and institutions that are making an ecological conversion. We need to go forward on this road and do more,” Francis said.

The pontiff cited an urgent need to discuss models of development.

“Now is the time for new courage in abandoning fossil fuels to accelerate the development of zero- or positive-impact sources of energy,” Francis said.

He told the young people: “Our generation has left you with a rich heritage, but we have not known how to protect the planet and are not securing peace.”

He lamented a lack of “creativity, optimism, enthusiasm,” and told young people that “we are grateful to God that you are here. Not only will you be there tomorrow, but you are here today.”