Non-profits in Massachusetts were optimistic about Boston Mayor Marty Walsh’s trip to the Vatican this week, local leaders told Metro.

Roundtable discussions with Pope Francis began on Monday. The Pontiff invited 50 leaders from around the world to Rome to discuss climate change and human trafficking as part of an effort to make progress on the global issues.

Attention from the Catholic leader, mixed with on-the-ground support from mayors including Walsh, can help spread greater awareness on the science of climate change and the power cities have to combat it, said Erwan Monier, research scientist for the Center for Global Change Science at MIT.

“This is certainly important to convince the general public that remains skeptical that this is one of the most serious societal issues we are facing,” Monier said.

The meeting could help bring attention to the sex trafficking trade, which is “huge” in Massachusetts, said Zina Cranmer, executive director of Demand Abolition, a Cambridge non-profit advocacy group.

Cranmer said she hoped the visit would fight misconceptions about sex trafficking as the industry has evolved -- flourishing online, funding gang violence and taking advantage of children in the child welfare system. Walsh and his peers are uniquely positioned to train law enforcement, provide services and educate the public, she said.

“I think the Pope recognizes mayors are incredibly important in terms of actually making change on the ground,” Canmer said.

Direction from the Pontiff trickles down into congregations and faith-based groups working in the state, said Anthony Barsamian, vice president of the Massachusetts Council of Churches.

“These are the top moral issues of the day. If you don’t stop these kinds of blights on our country and our world, it will damage the fabric of everything,” Barsamian said. “The Pope will take a very strong stand on that and church leaders will follow by taking action.”