One hails from Tonga, where climate change is threatening the very existence of the archipelago. Several live in places tormented by drug violence and organized crime. Another represents a tiny, remote church that has witnessed first-hand the deadly drama of Mediterranean migration.

The 20 men from 18 countries who will join the College of Cardinals on Saturday reflect the far-flung diversity of the Catholic Church. But they also represent unity in living out some of Pope Francis' core concerns — and will bring that experience to bear when they eventually elect his successor.

Francis will formally elevate the 20 new cardinals at a ceremony in St. Peter's Basilica in the second such consistory of his pontificate. Like the first, Francis looked to the "peripheries" for new cardinals, giving countries that have never before had one — Tonga, Myanmar and Cape Verde — representation at the highest level of the Catholic Church.

Francis also looked to the peripheries closer to home in Italy, once again ignoring big archdioceses like Venice and Turin that have traditionally had a cardinal, to instead elevate prelates from small and often overlooked Italian dioceses.

Francesco Montenegro — the cardinal-designate from one of those dioceses, Agrigento, Sicily — was on hand to welcome Francis in July 2013, when the pope made his first trip outside of Rome to visit the tiny island of Lampedusa, destination of choice for migrant smugglers since it's closer to Africa than the Italian mainland.

There, Francis greeted several hundred recently arrived refugees and thanked the residents who have seen tens of thousands more arrive over the years, and sometimes helped bring their bodies ashore when they died at sea.

In Lampedusa, Francis denounced the "globalization of indifference" that much of the world shows to refugees, a message he repeated just this past week in decrying the deaths of some 300 migrants lost at sea.

Cardinal-elect Soane Patita Paini Mafi hails from Tonga, which as a tiny island state in the middle of the Pacific Ocean is on the front lines in coping with the effects of global warming.

Tonga has never before had a cardinal, and Mafi's concerns about climate change are very much in line with those of the pope, who is writing an encyclical on the environment that has already irked climate change deniers in his own church.

"The pope has gone where no pope has ever gone before which is to dioceses that are so far away from Rome and so small that they have never really showed up on the Vatican's radar before," said John Thavis, author of "The Vatican Diaries."

While cardinals are called on to advise the pope, their primary job is to elect a new one. Only those under age 80 can participate in a conclave; in addition to naming 15 voting-age cardinals, Francis also made five elderly churchmen cardinals to honor their service to the church.

Only one Vatican official is getting a red hat, further evidence that Francis wants to reduce the number of titled Holy See bureaucrats. The new in-house "prince of the church," Cardinal-designate Dominique Mamberti, was the Vatican's foreign minister before replacing the hard-line, tradition-minded Cardinal Raymond Burke as the Vatican's top judge.

Mamberti is one of only a handful of Europeans to join the college, and in fact the overall percentage of European cardinals will now be lower than it has ever been.

In addition to Myanmar, Tonga and Cape Verde, which are getting cardinals for the first time, other far-flung places getting red-hatted representation include Hanoi, Vietnam; Addis Ababa, Ethiopia; and Bangkok, Thailand.

"These countries have ecclesial communities that are small, or that represent a minority within their country," noted the Rev. Federico Lombardi, the Vatican spokesman.

Many of the men work in pastoral settings that Francis, who ministered to Argentina's poor while Buenos Aires archbishop, knows all too well. The archbishop of David, Panama, Cardinal-designate Jose Luis Lacunza Maestrojuan, works with indigenous peoples to protect them from mining interests. Cardinal-designate Alberto Suarez Inda of Morelia, Mexico lives in a place that has been wracked by drug cartel violence.

Several of the new cardinals are or were presidents of their national or regional bishops' conferences, meaning they have already received votes of confidence from their fellow bishops. Francis has said he wants church decision-making to revert back to local churches and be less centralized in Rome.

"It looks like working well with other bishops is more important to Pope Francis than connections in the Roman Curia," the Rev. Thomas Reese wrote in the National Catholic Reporter.

According to Reese's statistics, the overall geographic diversity of the College of Cardinals will be little changed, though Africa and Asia will have a slightly greater share of the votes than under previous popes (around 12 percent and 11 percent, respectively.)

Latin America — home to nearly 40 percent of the world's Catholics — stays roughly steady with about 16 percent, in a sign that the region's first pope isn't playing favorites.

For the second consistory in a row, no U.S. cardinal was named. The United States still counts 11 voting-age cardinals.

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