Almost none of us with an interest in the matter would have guessed that when Cardinal Joseph Ratzinger was elected pope in 2005, one of the characteristics of his tenure would be a commitment to many tenets of environmentalism. Yet this has turned out to be the case. One author, Woodene Koenig-Bricker, has called Pope Benedict XVI "the greenest pope in history."

The latest example of his thinking came recently when Benedict, on holiday in northern Italy, favorably mentioned the Jesuit priest/scientist Pierre Teilhard de Chardin, who is sometimes called "the Catholic Darwin," at a vespers service.

De Chardin, one of the last century's most important paleontologists, remained a controversial figure in some church circles long after his death in 1955. As a scientist, he took part in the 1912 discovery of Piltdown Man in Britain (later determined to be a hoax) and Peking Man in the 1920s and 30s while in China. As a priest and a scholar, his views on salvation, evolutionary theory and the universe clashed with church doctrine. (An excellent book on his life and career is "The Jesuit and the Skull" by Amir D. Aczel.)

The pope, who had a long and distinguished career as a theologian, was speaking on a letter of St. Paul in which Paul wrote that the world will one day become a form of living worship. "It's the great vision that later Teilhard de Chardin also had: At the end we will have a true cosmic liturgy, where the cosmos becomes a living host," Benedict said.

"Let's pray to the Lord that he helps us be priests in this sense, to help in the transformation of the world in adoration of God, beginning with ourselves," the pope added.

More than words
While Italian newspapers buzzed about what the pope "really meant" in the reference to de Chardin, the larger image of the pope's thinking on the environment and ecology was overlooked.

In several addresses, the pope has urged his followers to respect the Earth as God's creation, and noted how sustainability serves the needs of all's God's children, including the world's poor. And the pope is offering more than words. To wit:

• The Vatican is the first sovereign state to be carbon neutral. It has joined a reforestation program to offset its carbon emissions.

• Plans are underway to build Europe's largest (100 megawatts) solar power plant on church land.

• About 2,400 solar panels have been installed on the roof of Nervi Hall, where general audiences and concerts are held for up to 10,000 people.

• A solar heating/air conditioning unit has been installed at the Vatican staff cafeteria.

• The Vatican's engineers are investigating a renewable-energy project to break down biodegradable waste material to produce methane and gas at Castel Gandolfo, the pope's summer residence.

A social sin
Last year, the pope added "polluting the environment" to a list of social sins that need repentance. At other public and private talks, he has told a gathering of 400 priests that the environment has been undervalued by Catholics; preached on environmental protection to the United Nations, and spoken in strong terms about saving the rainforests.

The pope never deviates from church teaching on population issues, but he has repeated the idea that materialism and over-consumption are important social problems.

In his latest encyclical the pope stressed "the environment is God's gift to everyone." More strongly, he said: "The fact that some states, power groups and companies hoard non-renewable energy resources represents a grave obstacle to development in poor countries. … The international community has an urgent duty to find institutional means of regulating the exploitation of non-renewable resources, involving poor countries in the process, in order to plan together for the future."

And, according to one report, he's even asked his people to check into converting the popemobile to electric power.