Benedict also told reporters while flying to Sydney to start a 10-day visit that he would work for "healing and reconciliation with the victims" of sexual abuse by Catholic clergy there "just as I did in the United States" earlier this year.
Less than an hour after the pope's flight took off from Rome, Benedict walked back to the section where journalists sat and met with them for about 15 minutes. He called on five journalists to ask questions that had been submitted to the Vatican earlier in the week.
One asked about climate change following discussions on the environment during this month's G-8 summit in Japan.
There is a need to "wake up consciences," Benedict responded. "We have to give impulse to rediscovering our responsibility and to finding an ethical way to change our way of life."
Benedict said that politicians and experts must be "capable of responding to the great ecological challenge and to be up to the task of this challenge."
"We have our responsibilities toward Creation," Benedict said, stressing, however, that he had no intention of weighing in on technical or political questions swirling around climate change.
Benedict said he would address the problem of sexual abuse by Catholic clergy.
He reiterated his view that sexual abuse is "incompatible with the behavior" required of priests. At the start of his U.S. pilgrimage, Benedict had said he was "deeply ashamed" of the abuse scandal and pledged to work to make sure pedophiles do not become priests.
Benedict acknowledged in comments to reporters Saturday aboard the plane that the Church in the West was "in crisis" but insisted it was not in decline. "I am an optimist" about its future, he said.
The Australia pilgrimage is the longest in his three-year-old papacy and will test the 81-year-old pontiff's stamina. Tens of thousands of young pilgrims are awaiting him in Sydney.
Although aides say the pope is in fine health, the Vatican appeared to be taking no chances to ensure Benedict is fit for the church's World Youth Day festival.
With little advance notice, it canceled Benedict's weekly public audience this past Wednesday as well as most other meetings to give him as much rest as possible.