VATICAN CITY — Religious leaders need to tell congregations that global warming can affect not just the environment, but also the spread of diseases and other threats to human health, participants said at a Vatican conference on Saturday on climate change, an issue that has been a priority of Pope Francis.

Persuasion “starts with the tenets of faith” more than with scientific data, said the Rev. Leith Anderson, president of the United States-based National Association of Evangelicals, noting that most of the world’s population has some religious affiliation. “Environmental catastrophes” like recent storms, flooding and droughts, he said, “create opportunities to persuade.”

The Rev. Mitchell C. Hescox, president of the Evangelical Environmental Network, said he had given hundreds of talks on the issue. “Many evangelicals believe in climate change or understand the science in climate change, but they still see it as a future event,” he said. “It’s not something they have to worry about, and that is what we have to change.”

Mr. Hescox added: “The way to move conservatives around the world is to talk about how it impacts or affects their children, their own lives.”