Pope Francis has arrived in Rio de Janeiro, Brazil, for World Youth Day, making his first overseas trip since taking office. As the first pope from the Americas, the former Archbishop Jorge Bergoglio of Buenos Aires, Argentina, will be seeking to energize young Catholics in his home continent.

While there are more Roman Catholics in Latin America and the Caribbean than in any other region, and more Catholics in Brazil than in any other country, Francis encounters a changing religious landscape there. A Pew Research analysis of 2010 census data shows that 65% of Brazilians describe themselves as Catholic, down from 92% in 1970. That decline has been accompanied by growing shares of Protestants and the religiously unaffiliated.

Out of the more than 120 million Catholics in Brazil as of 2010, an estimated 32.6 million are between ages 15 and 29. However, the percentage of young people in Brazil identifying as Catholic has fallen by 29 percentage points in the past four decades, from 92% in 1970 to 63% in 2010.

Brazilian Catholics tend to be older and live in rural areas. In fact, less than half (46%) of the population of Rio de Janeiro is Catholic. Read more

Michael Lipka  is an associate director focusing on news and information research at Pew Research Center.