Pope Benedict XVI called for "sobriety and solidarity" in 2009 as the world struggles with economic and social woes.
His appeal was made amid the splendor of St. Peter's Basilica during a New Year's Eve vespers service on Wednesday.
Benedict described these times as being "marked by uncertainty and worry for the future" but told the faithful not to be afraid. He urged governments to help families in difficulty and said Catholic charities are doing as much as possible to help out.
A choir sang during the service, attended by cardinals, other clergy, pilgrims and tourists.