(ABC NEWS) -- With 1 billion Catholics worldwide, the face of the church is changing.
It's something the cardinal electors may keep in mind when the conclave to elect a new pontiff begins in late March, said Matthew Bunson, general editor of the Catholic Almanac and author of "We Have a Pope! Benedict XVI."
The 117 cardinals who are eligible to vote for the new pontiff hail from approximately 50 different countries, and they almost always elect one of their own.
Joseph Ratzinger, an intellectual and respected cardinal from Germany, was the frontrunner for the papacy in 2005, Bunson said. When elected, he became Pope Benedict XVI.
This year, there are no strong favorites.
"The door, in a way, is very much open," Bunson said.
Here's a quick look at some of the possible picks for pope:
Angelo Cardinal Scola, 71, Italy
Scola was named the Archbishop of Milan in 2011, a prominent post in the Roman Catholic church.
"If we had to pick a frontrunner, it's him," Bunson said. "He first is a brilliant theologian and has the intellectual heft to be pope, which is crucial. He has the clear favor of Pope Benedict.
Milan and Venice together have produced five popes in the past century.
Scola is also committed to promoting an understanding across faiths.
He started the Oasis Foundation in 2004, which helps bridge a dialogue between Christians and Muslims.
Helen Alvaré, a professor of law at George Mason University and an advisor to Pope Benedict XVI's Pontifical Council for the Laity, agreed that Scola will be considered papabili -- an Italian word for someone highly qualified for the papacy.
"It would not be surprise me if a Scola, or another great European mind also was determined to be what was needed for the times," she said.
Marc Cardinal Ouellet, 68, Canada
The former Archbishop of Quebec, who now heads the Congregation of Bishops, has a deep knowledge of the global workings of the church, Bunson said.
"He has had a major role in the appointment of the church's leaders around the world," Bunson said.
And he points out that at 68 years old, Ouellet has age on his side.
Ouellet is someone who could have "worldwide reach," Alvaré said.
"The man who is chosen for the position he has is someone who is understood to have the presence and the future of the church in mind," she said.
Peter Cardinal Turkson, 64, Ghana
Turkson, who hails from Ghana, may be in the running.
He is currently the president of the Pontifical Council for Justice and Peace, a post he was appointed to by Pope Benedict XVI in 2009.
The job has sent Turkson, who speaks six languages, around the world to handle mediations.
"The fact that an African cardinal is a candidate to be elected pope is the statement to the diversity of the church and the remarkable growth around the world," Bunson said.
Turkson discussed the possible of a black pope at a press conference in 2009, following the U.S. presidential election.
"And if by divine providence -- because the church belongs to God -- if God would wish to see a black man also as Pope, thanks be to God," he said.
Francis Cardinal Arinze, from Nigeria, has also been discussed as a potential pope.
Leonardo Cardinal Sandri, 69, Argentina
With a large center of Catholic faithful in Latin America, Sandri could become the first pope from the region.
The 69-year-old, who was born in Argentina to Italian parents, served as a chief of staff in the Vatican, often reading public message when Pope John Paul II was in declining health.
It was Sandri who announced the passing of the pontiff in St. Peter's Square on April 2, 2005.
"He's well-liked around the world," Bunson said.
He currently serves on the Congregation for the Oriental Churches, acting as a liason with Eastern European Catholic churches.
Sandri is fluent in English, Spanish, Italian, German and French.
Angelo Cardinal Bagnasco, 70, Italy
The Archbishop of Genoa has a "reputation for intellectual heft," Bunson said.
Bagnasco, two-time president of the Italian Bishops Conference, has a history of taking a strong stance on church doctrine.
In 2007, he was the subject of death threats after he led a campaign against proposed Italian legislation to grant some legal rights to unmarried couples, including people in same-sex relationships.
Italians form the largest voting block in the College of Cardinals, with 25 percent of the seats, and could help propel Bagnasco into the papacy.
Tarsicio Cardinal Bertone, 78, Italy
The current Cardinal Secretary of State is a strong candidate if the Holy Spirit wants another great European mind at the helm of the church, Alvaré said.
Bertone runs the day-to-day business of the Roman Curia, the Vatican's government.
He has reportedly been criticized by Vatican officials for his handling of issues ranging from sexual abuse in the church to Vatican finances.
In an open letter last year, Pope Benedict XVI acknowledged the in-fighting and pledged his support for his secretary of state.
"I've noted with regret the unjust criticism directed at your person," the pope wrote. "I intend to reaffirm my pledge of personal faith in you."
Although he's held in high regard by the pope, Bunson believes Bertone's age will keep him from the papacy.
"His age is against him," he said, pointing out that Bertone is the same age as his boss when he was elected.
Timothy Cardinal Dolan, 63 New York
While the thought of an American pope has long seemed impossible, Cardinal Dolan should not be ruled out, Alvaré said.
"History is changing," she said. "We've been at this a while here in the states, [although] not anywhere as long as Europe."
Dolan, an affable cardinal well-known by Catholics in the U.S. and abroad, "has been grappling with some of the leading questions that face the church for the future," Alvaré said.
In September 2012, along with comedian Stephen Colbert, he co-led a discussion on faith and humor at Fordham University.
"If I am elected pope, which is probably the greatest gag all evening, I'll be Stephen III," he told the crowd of students.
Despite Dolan's good standing, Bunson said he has some doubts.
"It strikes me as unlikely, simply because we are the world's last superpower," he said of the U.S. "So I think that might factor in."
By Alyssa Newcomb