Read this Reuters article.
Here are some excerpts:
"Pope Benedict on Sunday called on Catholics to keep the Sabbath a day set aside for reflection on their faith and the fate of the planet and not surrender it to "the mad rush of the modern world"."
"Calling Sunday the Church's "weekly feast of creation," the Pope said the day also should be a weekly reminder of the dangers to the planet."
"At a time when creation seems to be endangered in so many ways through human activity, we should consciously turn our attention to this dimension of Sunday too," he said, speaking in German.
Last Sunday in central Italy, Benedict led the Catholic Church's first 'eco-friendly' youth rally and told up to half a million people that world leaders must make courageous decisions to save the planet "before it is too late".
Under Benedict and his predecessor John Paul, the Vatican has become progressively "green". It has installed photovoltaic cells to produce electricity and hosted a scientific conference to discuss the ramifications of global warming and climate change, widely blamed on human use of fossil fuels.
In July, Benedict said the human race must listen to "the voice of the Earth" or risk destroying its very existence."