More than a decade ago on an Aegean island, the spiritual leader of the world's Orthodox Christians made a startling proposition: That pollution and other attacks on the environment could be considered sins.
At the time, the idea earned him little more than a nickname - the "green patriarch."
It's no longer such a radical view.
Eco-friendly attitudes have increasingly moved into the mainstream of many faiths - from Muslim clerics urging water conservation in the fast-growing Gulf states to evangelical preachers in the United States calling attention to global warming.
Next week, Ecumenical Patriarch Bartholomew I will lead another high-profile group of religious leaders, scientists and activists on a trip to examine the interplay of faith and ecology. The weeklong voyage along the Amazon starting next Thursday will be Bartholomew's sixth green journey since the first in 1995 to the Greek island of Patmos - where biblical tradition says the book of Revelation was compiled.
The efforts of Bartholomew and others have energized some of the most lively theological explorations in recent years - with fresh studies and interpretation of Scripture along environmental lines. The global movement also offers rare common ground for religious groups at a time of confrontation on issues from gay clergy to suspicions between the Muslim world and the West.
"The environment brings a sense of urgency and shared purpose that few other issues can bring," said Mary Evelyn Tucker, a co-founder of the Forum on Religion and Ecology, a group that will begin a relationship with Yale University in September. "It cuts across all religious traditions."
Evidence of an expanding environmental ethos can be found in nearly every faith.
In New York, the Coalition on the Environment and Jewish Life draws clear links between Judaic traditions and the battles to ease global warming. In China, a Buddhist conference in April urged greater emphasis on environmental protection. Hindu religious scholars have raised alarms about possible environmental fallout from the rapid modernization in India.
In June, Pope Benedict XVI told a crowd in St. Peter's Square to shun "fake freedoms which destroy the environment and man," though he did not elaborate.
In Iran, Grand Ayatollah Yusef Saanei said it was "the duty of every Muslim" to protect the environment. Many fatwas, or religious edicts, across the Muslim world echo similar Quranic readings that God entrusted humans to protect the earth.
"Religion is built on story telling. The stories reach people in ways that academics or activists or NGOs cannot," said Victoria Finlay, a spokeswoman for the Alliance of Religions and Conservation, a London-based group founded by Prince Philip, the husband of Queen Elizabeth.
"It took a while for the two sides to begin to understand each other. But now the NGOs and others recognize what a powerful force religion can play."
Among the alliance's current projects is encouraging Muslim imams in Kenya to denounce the widespread use of dynamite to catch fish and push for a return of traditional nets, which trap large fish but allow smaller, breeding-age fish to escape.
"The environment is a great unifier," said the Rev. James Keenan, a Boston College moral theologian who is hosting a meeting of more than 400 Catholic scholars in Padua, Italy, starting Saturday. "You are not going to find anyone saying, `Well, there is no moral connection between religion and the environment.' All the faiths can bring something to the table."
Bartholomew's trip hopes to draw the attention of religious leaders to the critical pressures facing the Amazon, including clearing pristine rain forest for farmland. One goal is to tap the immense reach of Brazil's Pentecostal and evangelical-style churches, which continue to chip away at the Roman Catholic majority.
In the United States, many evangelical leaders have discovered the message of ecology - drawing links between the biblical command for proper stewardship of the Earth and environmental activism.
The Evangelical Environmental Network - best known for its clean-air campaign "What Would Jesus Drive?" - opened a new effort earlier this year against global warming, the Evangelical Climate Initiative, which drew some of its most prominent supporters to date, including the Rev. Rick Warren, author of the runaway best seller "The Purpose Driven Life."
But some skepticism remains within the evangelical community.
Christian leaders with close ties to the Bush administration, calling themselves the Interfaith Stewardship Alliance, said "the science is not settled on global warming," and argued that most evangelicals do not back the call for regulating greenhouse emissions. Among the alliance's supporters are James Dobson, founder of Focus on the Family, and the Rev. Richard Land, head of the public policy arm of the Southern Baptist Convention.
Still, small acts indicate the mood of many congregations, like the Unitarian church in Lewisburg, Pa., that's looking for a new building.
The congregation recently sold its historic home and is working with an architect who specializes in designing "green" places of worship. It techniques include recycled construction materials and aligning the structure to use the maximum natural light.