"Accepting the urgency, it seems clear to me also that climate change is a problem which can no longer be left to our future generation," the pope said. "When it comes to the care of our common home, we are living at a critical moment of history. We still have time to make the change needed to bring about a sustainable and integral development, for we know that things can change."
The pontiff also stressed the role that the international community should serve in looking after refugees and other people throughout the world who are not as fortunate to have the same freedoms and rights as those in the West.
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"I would like all men and women of goodwill in this great nation to support the efforts of the international community to protect the vulnerable in our world and to stimulate integral and inclusive models of development, so that our brothers and sisters everywhere may know the blessings of peace and prosperity which God wills for all His children," Francis urged.
Following the pope's speech, he and Obama met privately in the Oval Office, where, according to a White House official, Obama gave the pontiff a metal sculpture of an ascending dove (the Christian symbol for the Holy Spirit), which is made from an original armature bar from the Statue of Liberty.
In attendence at the pope's White House visit was former secretary general of the World Evangelical Alliance Geoff Tunnicliffe, who has personally met with Pope Francis three times in the past year to build a friendship and discuss "common areas of concern" between Catholics and Evangelicals, such as poverty, human trafficking, persecution and social justice.
"It was a warm speech, but I think it was provocative as well and hit some of the areas that need to be dealt with," Tunnicliffe, who is the advisory board chairman for The Christian Post's umbrella company Christian Media Corporation, told CP after the pope's visit. "I think there was real warmth in the crowd as well and a lot of enthusiasm for what he was saying. I think he is off to a great start here in the U.S., and I think he is not going to shy away from the difficult issues."
Tunnicliffe praised Pope Francis for addressing issues like climate change and the protection of religious liberty.
"Pope Francis, in particular, emphasized the care for the vulnerable and he spent a lot of time on the climate change issue. He talked about our 'common home,' which I think is great language to describe this climate that we live on," Tunnicliffe said. "Obviously, that is a passion for him. He referred to many of the key issues that concern us — religious freedom, extreme poverty, and those are probably just highlighting somethings that I guess that he will be dealing with in the coming days."
After his White House visit, the Pope led a prayer for the U.S. bishops at the St. Matthews Cathedral in Washington, D.C. During the evening Wednesday, Francis will hold a canonization mass in Spanish for 25,000 ticket holders at the Basilica of the National Shrine of the Immaculate Conception in Washington, D.C.
The pontiff will address a joint session of Congress Thursday morning before he travels to New York City. After arriving in New York, the pope will hold a Mass at St. Patrick's Cathedral. On Friday, he will meet with the United Nations General Assembly and will also hold a mass at Madison Square Garden.
The pope will then travel to Philadelphia on Saturday, where he will hold a prayer vigil for the World Meeting of Families, which is the largest meeting of Catholic families held every three years. Later in the day, he will visit the Liberty Bell and Independence Hall, the location where the U.S. Constitution and Declaration of Independence were signed.
On Sunday, the pope will hold a papal meeting in the morning with bishops at St. Martin's Chapel of St. Charles Borromeo Seminary in the suburbs of Philadelphia. At 4 p.m., the pope will hold a mass for the World Meeting of Families.
The pope will depart for Rome on Sunday night.