CHARLESTON — A black water swamp in South Carolina owned by the Audubon Society is helping companies in California meet their carbon emission goals to ease global warming.


About 5,200 acres of the 17,000-acre Francis Beidler Forest, Audubon Center and Sanctuary near Harleyville have been registered with California’s cap and trade program as carbon offsets in a program that also brings dollars to preserve the South Carolina landscape.


In cap and trade, the government issues permits allowing companies to emit a certain amount of greenhouse gases but giving them flexibility how they comply. They can trade emissions permits with each other and, in California, can purchase credits to offset as much as 8 percent of their emissions.


The offset credits can be purchased from registered projects that prevent greenhouse emissions. In the case of the Beidler Forest, it is land that will remain the same and the carbon stored in the trees will never enter the atmosphere through burning or a change in land use.


More than 5,500 acres at the forest about 40 miles northwest of Charleston is covered by a conservation easement, a legally binding document meaning it can never be developed. The forest has 1,800 acres of virgin cypress and tupelo black water swamp, considered the largest tract of its type in the nation.


Scientists surveyed the forest and verified the offset area contains 450,000 metric tons of carbon that have been registered as credits.


More than half of those credits have been sold since the offsets were registered last year, said Norman Brunswig, the executive director of Audubon South Carolina. Audubon, working with Blue Source, the San Francisco company that worked to register the credits, wanted not less than $8 a ton, he said. Eighty percent of the sale price comes to Audubon.


“We are taking our portion of the money and putting it in an endowment. Those designated funds will support this forest indefinitely,” Brunswig added.


“It’s a really big deal for us. We are in the business of managing forests and motivating other people to conserve and manage forests,” he added. “Finding a way to fund that management and conservation is always a challenge.”


Jeff Cole, the vice president of portfolio development for Blue Source, said there will be additional offset credits available in the future as the forest grows.


Every six years, a third party will survey the forest to verify the carbon quantity. Generally there will be more as the forest grows, although storms and fires could reduce the amount of carbon.


“At the end of the day, it all comes out to what is on the ground,” he said. “The landowner can generate future credits with ongoing growth or sequestration.”


Sequestering the forest – doing nothing to it – would mean more carbon, and more credits, than if the trees were thinning periodically.


“We as an institution like to work with forest landowners to help them find ways to enjoy revenue from their land,” Brunswig said. “We saw carbon as something we could try and if it were successful we could then be a model for other landowners.”