ROME — California Gov. Jerry Brown, Boston Mayor Martin J. Walsh, and more than four dozen mayors and local officials will join Pope Francis here in late July for workshops on modern slavery and climate change.

The sessions are jointly organized by the Vatican’s Academy for Sciences and the United Nations.

Representatives of Boston, New Orleans, San Francisco, San Jose, Birmingham, Minneapolis, and Seattle, as well as Paris, Stockholm, Vancouver, Mexico City, and Rio de Janeiro, will participate in the July 21-22 meetings.

This the latest cooperative effort on humanitarian causes between the Vatican and the UN, despite differences on issues such as population control, and once again Vatican officials felt compelled to defend partnership.

“The United Nations aren’t the devil,” said Argentinian Bishop Marcelo Sánchez Sorondo, head of the Vatican’s Pontifical Academy for Sciences, at a Vatican news conference Wednesday.

“Pope Paul VI called the UN the modern way of civilization, and promised full cooperation with those things that don’t go against the Church’s moral teachings,” he said.

In fact, the Vatican was a proponent of the creation of the UN in 1945 and has been a permanent observer since 1964. Every pope since Paul VI in 1965, except John Paul I who reigned for just a month, has addressed the UN General Assembly.

Both the workshop titled “Modern Slavery and Climate Change: the Commitment of the Cities,” and the symposium titled “Prosperity, People, and Planet: Achieving Sustainable Development in Our Cities,” will be hosted by the Pontifical Academies of Sciences and Social Sciences, the Vatican office headed by Sánchez.

The meetings will bring together mayors and officials from around the world to discuss how cities can contribute to the solution of modern-day slavery — human trafficking, child labor, forced prostitution, and illegal labor — and climate change.

Sánchez said the climate crisis and modern slavery are “interconnected emergencies,” and said that even though “the poor and the excluded have the least effect on climate change … they are the most exposed to the terrible threat posed by human-induced climate disruption.”

These workshops are a direct result of a previous, still-standing Vatican initiative that brings together police chiefs and bishops to fight human trafficking, he said.

During those meetings, Sánchez said, police officials often say that even though the bishops’ commitment was important, little could be done without the involvement of governors and mayors.

“We intend for the mayors to commit to promoting the empowerment of the poor and of those who live in vulnerable conditions in our cities and in our urban settlements,” Sánchez said, arguing that environmental, economic and social instabilities create “fertile ground for forced migration and human trafficking.”

Pope Francis’ commitment to fighting human-caused climate change has been clear since the beginning of his pontificate. His recently published encyclical, Laudato Si’, was released in part to influence two looming UN summits on the matter – one in New York, and another in Paris.

Consultant Michael Shank, who’s helping the Academies of Science organize next week’s meetings, said he expects the Vatican to ask UN member states to include the fight against modern-day slavery in their sustainable development goals, a set of targets that nations are supposed to use to set policies for the next 15 years.

Those goals are scheduled to be signed by more than 193 heads of state in September during a session of the UN General Assembly, which will open with an address by Pope Francis.