Members of congregations across Rhode Island are joining an international effort to turn out their lights for one hour at 8:30 Saturday night to show their support for combating climate change.

The folks who operate One Financial Plaza, once known as the Hospital Trust Building, are joining too, by extinguishing the lights around the roof.

Governor Carcieri’s staff just learned of the campaign yesterday, but it is considering taking part, too, at the State House.

The lights-out campaign, called Earth Hour 2009, is being supported in 2,400 cities in 82 countries, according to its organizers, led by the World Wildlife Fund. They say landmarks such as the Great Pyramids in Egypt, the Acropolis in Greece and Rockefeller Center in New York City have all agreed to turn off their lights.

The movement traces its origins to 2007, when the World Wildlife Fund and the city of Sydney, Australia, teamed up to turn out the lights in that city. Last year the movement grew to actions in 35 countries, according to the organizers.

Rhode Island Interfaith Power and Light, an organization in the faith-based community that works to encourage energy efficiency and mitigate global warming, announced Thursday its support of Earth Hour 2009 and encouraged all Rhode Islanders of faith to participate.

“Global warming is no longer a question, and no longer a mere economic or political problem,” said Howard Brown, director of Interfaith Power and Light. “Stewardship of Creation is a moral issue. It speaks to how we treat the gifts that have been given to us, and what steps we’re willing to take to help protect those less fortunate than ourselves, who will disproportionately suffer the effects of global warming in the form of forced migration and starvation.”

Emmanuel Episcopal Church in Newport agreed to participate, and called on its parishioners to join as well. So did First Universalist of Burrillville, and North Kingstown United Methodist.

Throughout the day Thursday, Brown got e-mails from other parishioners pledging to join the campaign.

Laurie Drucker, property manager for CB Richard Ellis, which operates One Financial Plaza for Meritage Properties, said her company has a strong sustainability culture so it was anxious to take part in the campaign, which also includes several big buildings in Boston. Once it heard about the event, she said, it was a given that it would participate.

Ironically, she said, the company was asked to keep the lights on all night earlier in the week by those making a feature film in Providence.

For more information, a video and to register, go to: www.earthhourus.org/video.php

plord@projo.com