Government officials take photos of their feet on the same spot where Pope Francis stood during the welcoming ceremony Friday, January 16, 2015 at the Presidential Palace grounds in Manila, Philippines. Pope Francis arrived Thursday for a five-day apostolic visit in this predominantly Catholic nation in Asia. (Photo by Bullit Marquez/AP Photo)

In this Saturday, January 17, 2015 file photo, Pope Francis waves to the faithful on his arrival in Tacloban, Philippines as rain drips from the roof of his vehicle. For months, Francis has been drafting an encyclical on the environment and global warming which he hopes to release by June or July 2015. In a news conference as he traveled last week to the Philippines, he said global warming was “mostly” man-made. And he said he wanted his encyclical out in plenty of time to be absorbed before the next round of U.N. climate change talks in Paris in November after the last round in Lima, Peru, failed to reach an agreement. (Photo by Wally Santana/AP Photo)

In this Friday, January 16, 2015 file photo, Pope Francis, center, followed by Cardinal Luis Antonio Tagle, waves as he arrives at the Mall of Asia arena, in Manila, Philippines, for a meeting with families. It's a scene that has repeated itself throughout Pope Francis' visit to the Philippines, from the sidewalks lining his motorcade routes to the hallowed nave of Manila's cathedral: arms stretched high in unison, holding aloft smartphones and tablets to record the moment. (Photo by Alessandra Tarantino/AP Photo)

Pope Francis passes past a portrait of himself as he arrives to meet youths in Santo Tomas University in Manila, Philippines, Sunday, January 18, 2015. Francis is in the Philippines on Sunday, the final full day of a weeklong trip that also took him to Sri Lanka. (Photo by Alessandra Tarantino/AP Photo)

Nuns wear raincoats as thousands of people gather at Rizal Park to attend a mass by Pope Francis in Manila January 18, 2015. Huge crowds converged on the Manila park on Sunday to see Pope Francis wrap up his Asian trip with an outdoor Mass expected to draw one of the largest crowds in Philippine history. (Photo by Erik De Castro/Reuters)

Nuns shield themselves from the rain as thousands of people gather at Rizal Park to attend a mass by Pope Francis in Manila January 18, 2015. (Photo by Erik De Castro/Reuters)

People shield themselves from the rain as they gather at Rizal Park to attend a mass by Pope Francis in Manila January 18, 2015. (Photo by Erik De Castro/Reuters)

Pope Francis waves as he arrives for a meeting with young people at Manila university, January 18, 2015. The pope held morning meetings with religious leaders and young people at the university before the Mass. (Photo by Stefano Rellandini/Reuters)

Pope Francis embraces a boy and a girl during a meeting with young people at Manila university, January 18, 2015. (Photo by Stefano Rellandini/Reuters)

A girl holds a bible as Pope Francis arrives for a meeting with young people at Manila university, January 18, 2015. (Photo by Stefano Rellandini/Reuters)

Youths cheer as Pope Francis arrives for a meeting with young people at Manila university, January 18, 2015. (Photo by Stefano Rellandini/Reuters)

Pope Francis touches a crucifix during a meeting with young people at Manila university, January 18, 2015. (Photo by Stefano Rellandini/Reuters)

A girl attends a meeting with young people led by Pope Francis at Manila university, January 18, 2015. (Photo by Stefano Rellandini/Reuters)

Pope Francis looks on during a meeting with young people at Manila university, January 18, 2015. (Photo by Stefano Rellandini/Reuters)

Pope Francis joins hands with children while students perform during a meeting with youth at the University of Santo Tomas in Manila January 18, 2015. An emotional Francis, moved by the tears of an abandoned child, said on Sunday the world needed to “learn how to cry” over the plight of the millions of poor, hungry, homeless and abused children. (Photo by Romeo Ranoco/Reuters)

Pope Francis hugs children during a meeting with the youth at the University of Santo Tomas in Manila January 18, 2015. (Photo by Romeo Ranoco/Reuters)

Pope Francis gestures during a meeting with the youth at the University of Santo Tomas in Manila January 18, 2015. (Photo by Romeo Ranoco/Reuters)

Pope Francis waves to pilgrims during a meeting with youths at the University of Santo Tomas (UST) in Manila January 18, 2015. (Photo by Romeo Ranoco/Reuters)

Pilgrims wear raincoats while holding statues of Baby Jesus during Pope Francis' meeting with youths at the University of Santo Tomas (UST) in Manila January 18, 2015. (Photo by Romeo Ranoco/Reuters)

Members of the Philippine National Police prevent well-wishers from moving forward as Pope Francis' motorcade passes by in Manila January 18, 2015. (Photo by Ezra Acayan/Reuters)

Well-wishers wait for the arrival of Pope Francis prior to an open-air Mass in Manila January 18, 2015. (Photo by Paul Barker/Reuters)

People listen to Pope Francis speak during an open-air Mass in Manila January 18, 2015. (Photo by Paul Barker/Reuters)

People wait in the rain for Pope Francis to lead an open-air Mass in Manila January 18, 2015. (Photo by Paul Barker/Reuters)

People raise religious statues before an open-air Mass led by Pope Francis in Manila January 18, 2015. (Photo by Paul Barker/Reuters)

A Catholic faithful holds a statue of child Jesus during an open-air Mass led by Pope Francis at Rizal Park in Manila January 18, 2015. (Photo by Cheryl Ravelo/Reuters)

A Catholic faithful hold a religious statue during an open-air Mass led by Pope Francis at Rizal Park in Manila January 18, 2015. Pope Francis concluded his trip to Asia on Sunday with an open-air Mass for a rain-drenched crowd in Manila that the Vatican and the government said drew up to seven million people, the largest ever for a papal event. (Photo by Cheryl Ravelo/Reuters)

A costumed performer raises an image of the Santo Nino (Holy Child) to the crowd hours before the final papal mass of Pope Francis at Quirino Grandstand in Manila, Philippines, Sunday, January 18, 2015. Millions filled Manila's main park and surrounding areas for Pope Francis' final Mass in the Philippines on Sunday, braving a steady rain to hear the pontiff's message of hope and consolation for the Southeast Asian country's most downtrodden and destitute. (Photo by Ron Soliman/AP Photo)