There is finally some good news from environmental scientists studying climate change: as the earth gets warmer, ancient redwood trees are thriving.

The huge trees that dot the California coast and the Sierra Nevada mountains soak up carbon dioxide from burning fossil fuels, keeping the potentially harmful greenhouse gas out of the atmosphere.

Despite the warming climate, redwood trees are growing faster than at anytime over the last century, according to a report issued today by the Redwoods and Climate Change Initiative.

"That's a wonderful, happy surprise for us," said Emily Burns, director of science for Save the Redwoods League, a San Francisco-based advocacy group.

California summers have warmed, but rainfall has remained steady. The hotter climate also burns off fog that normally shrouds the world's tallest trees, providing more access to nourishing sunlight, according to the report.

"The fact that redwoods grow faster rather than slower as fog decreases, that surprised us," said Bill Libby, a UC Berkeley forestry professor who was involved in the study.

The report is part of an ongoing research project to study the effects of climate change on redwood trees. Started in 2009, the project brings together scientists from UC Berkeley, Humboldt State University and Save the Redwoods League.

The report's findings are a refreshing respite from the normally pessimistic field of climate science, said Michele Luna, executive director of Stewards of the Coast and Redwoods, which supports Russian River-area state parks from its base at Armstrong Redwoods in Guerneville.

"It's nice to hear that there is something positive," she said. "This new research could be something that we want to share with our kids."

Redwoods remain threatened due to pressure from development, Burns said, and the report's findings show that the trees should be protected because they help fight climate change. Save the Redwoods League purchases forests to set aside as conservation areas.

"These results bolster our mission to protect redwoods because these trees are pulling incomparable amounts of carbon dioxide out of the atmosphere, which helps combat global warming," she said. "We have found ancient forests where climate conditions are accelerating growth and we predict these places will stay vibrant habitat refuges for other plants and animals in the foreseeable future."

Researchers also announced the discovery of the oldest coast redwood on record, a 2,520-year-old tree at Redwood National and State Parks near Crescent City.

The study, which looked at core samples from 16 2.5-acre forest plots along the California coast and the Sierra, is expected to last another 10 years. Other parts of the study will focus on younger redwoods and other redwood forest plant and animal species.

"With this research, we have laid the foundation for understanding how we can be responsible caretakers for these magnificent forests in the years ahead," said Harry Pollack, CEO for Save the Redwoods League. "We started this study because we can't afford to wait."