Back in the 1990s, when religiously based environmentalists were still viewed as nature worshippers, she founded Episcopal Power & Light. Now called Interfaith Power & Light, the nonprofit organization has 27 chapters across the United States, including North Carolina. The mission of the organization is to mobilize a religious response to global warming through the promotion of renewable energy and conservation.

Bingham, the president of Interfaith Power & Light and the environmental minister at Grace Cathedral in San Francisco, met with 20 religious leaders at St. Mark's Episcopal Church in Raleigh last week. She said religious communities have made remarkable strides in addressing the intersection of faith and global climate change, and she encouraged them not to give up.

"You clergy need to talk about it," she said. "I think it should be in every single sermon."

We caught up with her on the occasion of Earth Day on Tuesday to ask her about the progress religious people have made on the issue.

Q: How are churches becoming more active in environmental issues?

A: Environmental issues were once political issues. They didn't belong in the church. Now it's integral to mainstream religions in ways unimaginable five years ago. ... We're seeing changes in the liturgy to reflect care for creation. That's huge because in the Episcopal Church there's a deep tradition that resists change.

I am seeing clergy take this responsibility seriously enough to actually say that care for creation belongs with love, justice and peace. You hear the term "JPIC," or justice, peace and integrity of creation. It's putting care for creation on parallel with love, justice and peace ... We have a green mosque in Washington, D.C. We have hundreds of Protestant churches with solar panels on the roof. We have two large cathedrals with geothermal systems -- in Boston and in Cleveland, Ohio. The Catholic Cathedral in Los Angeles in solar.

Q: How has Interfaith Power & Light changed?

A: We now have an office in San Francisco and a staff of seven. We coordinate this national campaign. That means we help the state programs get started ... One of the important things we do is make sure the Interfaith Power & Light campaign doesn't get sidetracked. We don't want to be viewed as the Sierra Club at prayer. We're not political. We're not Republicans or Democrats. Our message is rooted in theology. It's different from an environmental organization. We want to be seen as conservative people coming from a theological perspective. We don't love trees more than people.

Q: What is the spiritual message you offer?

A: I see it as part of the commandment to love God and love your neighbor. If you love your neighbor, you don't pollute your neighbor's air. We are called to serve one another. If you see that your behavior is harming your neighbor and your neighborhood, other species, flora and fauna, or the next generation, it's a direct disobedience to the commandment. Jesus said what you do to the least of these you do to me. If vulnerable and poor communities are harmed by our behavior, we're insulting God.

Q: Would you call environmental degradation a sin?

A: If you knowingly drive a Hummer that gets 13 miles on the gallon and you don't care because you're big and important, that's a sin. These days, there are people who can afford to drive a Hummer but are buying a Toyota Prius. People want to do the right thing.

Q: How did Interfaith Power & Light get started?

A: I was on a mountaintop in Massachusetts with Steve MacAusland in 1996. We were both members of the Episcopal Ecological Network. We were on a trail walking, and frustrated that our committee never tackled any problems. We just talked about them. We knew that both California and Massachusetts were getting ready to deregulate electricity, and everybody would get to choose [their electric carrier]. We decided it was a great opportunity to show people where their electricity comes from. In this conversation, we thought 'Let's get the Episcopal Church to buy renewable energy.' That's how it began.