AUDIE CORNISH, HOST:
The issue of climate change is front and center for the Vatican. Pope Francis frames global warming as a moral issue, with the poor suffering most. In the coming months, he's expected to issue this special teaching document - it's called an encyclical - calling for global action. Now, in that vein, the Vatican today hosted a one-day conference, not just for religious leaders, but for scientists as well. NPR's Sylvia Poggioli was there and joins us now. And, Sylvia, there were actually some say heavy hitters at this conference. You had Nobel laureates, U.N. Secretary Ban Ki-moon - I mean, tell us who else was there.
SYLVIA POGGIOLI, BYLINE: Well, there were a few heads of state and then there were Protestant, Jewish, Muslim orthodox, Buddhist and Hindu leaders, as well as the Catholic hosts. And there were experts on sustainable development and economists. The title of the conference was Protect the Earth, Dignify Humanity: The Moral Dimensions of Climate Change and Sustainable Development. And, in fact, it really lays the groundwork for this much anticipated papal document that's called an encyclical on the environment that's expected in the summer. Ban Ki-moon said that document will provide an unprecedented opportunity to create a more sustainable future for the planet. And Francis will raise this issue also when he addresses the biggest gathering ever of world leaders at the special 70th anniversary session of the United Nations in September. Today's conference, you know, really was an example of a dialogue between faith and reason.
CORNISH: Help us understand this shift for the church. I mean, why does this issue seem to matter so much to this particular pope?
POGGIOLI: Well, actually, all three of Pope Francis's predecessors did speak out on the environment. He's done so more forcefully and more often, and he links environmental exploitation to social and economic inequality. One of the most interesting panels today was on one of his pet topics - the link between climate change and human trafficking - in the sense that the feeling is that should there be an increase in global warming, the most vulnerable will be the poorest on the globe, triggering massive human movements. A boom for human traffickers, as we see, are now operating in such huge numbers in the Mediterranean migrant crisis.
CORNISH: Sylvia, there are those who believe the Pope shouldn't be involved in this debate. And was their voice represented at the conference?
POGGIOLI: Well, not as speakers, but the - some were there as observers. They were members of the Chicago-based Heartland Institute, and they held a press conference here yesterday urging the pope not to back the United Nations's climate agenda. Now, many skeptics say the pope has no right to talk out on scientific issues, but Cardinal Turkson responded very sharply to that, saying the pope's ministry is about the salvation of people, which begins here on Earth. Now, the ironic fact is that the pope who took the name of the unofficial patron saint of the environment - St. Francis of Assisi - actually trained and worked first as a chemist before he entered a Jesuit seminary.
CORNISH: That's NPR's Sylvia Poggioli in Rome. Sylvia, thanks so much for speaking with us.
POGGIOLI: Thank you. Transcript provided by NPR, Copyright NPR.