SYDNEY, Australia Pope Benedict XVI said Thursday that mankind's "insatiable consumption" has scarred the Earth and squandered its resources, telling followers that taking care of the planet is vital to humanity.
The 81-year-old pontiff, appearing rested and in good form, gave his first major speech for Roman Catholicism's World Youth Day before adoring crowds who had traveled from 168 countries to see him in Australia's largest city.
As the sun set in the mild chill of the Australian winter, Benedict struck a theme that has earned him a reputation as the "green pope."
"Some of you come from island nations whose very existence is threatened by rising water levels, others from nations suffering the effects of devastating drought," the pope said, referring to global warming.
He noted that during his more than 20-hour flight from Rome to Sydney he had a bird's eye view of a vast swath of the world that inspired awe and introspection.
"Perhaps reluctantly we come to acknowledge that there are also scars which mark the surface of our Earth: erosion, deforestation, the squandering of the world's mineral and ocean resources in order to fuel an insatiable consumption," he said.
The crowd, some 200,000 young pilgrims gathered on a disused wharf on Sydney's harbor, waved their national flags and frequently applauded.
Benedict, a classical music lover who was reportedly given an iPod in 2006, has sought to reach out to young people through new media, sending daily mobile phone text messages citing scripture to thousands of registered pilgrims at the event signed with the tagline "BXVI."
Seeking to inspire a new generation, he warned the young Roman Catholics that a society without unwavering values is bound to suffer confusion and despair.
He decried alcohol and drug abuse and condemned "the exaltation of violence and sexual degradation, often presented through television and the Internet as entertainment."
"I ask myself, could anyone standing face to face with people who acutely do suffer violence and sexual exploitation 'explain' that these tragedies, portrayed in virtual form, are considered merely 'entertainment?"' Benedict said.
He told reporters during the flight from Rome to Australia that he believes the church in the West is in "crisis" because people feel they have no need for God. On Thursday, he warned the pilgrims of the threats from secularism.
"If God is irrelevant to public life, then society will be shaped in a godless image, and debate and policy concerning the public good will be driven more by consequences than by principles grounded in truth," he said.
It is all part of what he called a "poison" threatening to corrode the good in society.
"The concerns for nonviolence, sustainable development, justice and peace, and care for our environment are of vital importance for humanity," Benedict told the crowd.
Benedict was given a festive welcome for the youth event after three days of vacation in bush country outside Sydney to get over his jet lag. He boarded the Sydney 2000 liner for a cruise through Sydney's famous harbor, passing the white-shelled opera house and chugging beneath its twin landmark, the steel arched bridge nicknamed "the coat hanger."
He began the day by meeting with Prime Minister Kevin Rudd, praising the Australian government for its "courageous" apology to the country's indigenous Aborigines for past injustices. He said it offered hope to all disadvantaged peoples who are seeking their rightful places in society.
Aborigines are an often-marginalized minority of about 450,000 in Australia's population of 21 million. They are the country's poorest group, with the highest rates of unemployment, illiteracy, incarceration and alcohol abuse, and a life expectancy 17 years shorter than other Australians.
In February, Rudd formally apologized to Aborigines as one of his first official acts after taking power and made closing the gap between indigenous and non-indigenous Australians a priority of his government.
In 2001, Pope John Paul II issued a formal apology to the indigenous peoples of Australia, New Zealand and the Pacific islands for injustices committed by missionaries.
Benedict, who arrived Sunday on the longest pilgrimage of his just-over three-year-old papacy, scheduled an event-filled day Friday, including meetings with non-Catholics and a luncheon with 12 young Catholics. He is to fly back to Rome on Monday.