WASHINGTON — As wildfires burn across the West this summer, the nation’s forests have become entwined in the larger debate over climate change. They are both a victim of global warming and a potential solution in helping reverse the trend, by sopping up huge amounts of greenhouse gases.
Amid all the talk of carbon sequestration, biofuels and corporate average fuel economy, forests have been mostly overlooked on Capitol Hill.
By some estimates, the forests could absorb 500 million tons of carbon dioxide a year — about a third of the carbon dioxide the United States produces annually. Like all plants, trees soak up carbon dioxide as part of the process of photosynthesis, using the carbon to produce leaves and wood and releasing oxygen. Additional carbon is stored in the forest floor.
“If you are looking at greenhouse gases, forests are a great thing to focus on,” Forest Service chief Gail Kimbell said.
Yet with most things involving federal lands, controversy is brewing. Bureaucrats, scientists, timber industry officials and environmentalists are already sniping over how best to manage the forests in an era of global warming.
Based on nearly a century of detailed record-keeping on many of the national forests, Kimbell said there’s no question that temperatures are rising, the forests are drying out, underbrush is becoming thicker, and bug and disease infestations are mounting. Since 1986, the annual number of major forest fires has quadrupled, and the number of acres burned has grown sixfold. Nearly 50 percent of the Forest Service’s budget is spent on fighting fires.
“Fire managers say they are seeing behavior they have never seen before,” said Kimbell.
She said the best way to help contain forest fires is by clearing out the underbrush that has accumulated and thinning the stands.
About 13 million of the Forest Service’s 193 million acres have been cleared and thinned.
Kimbell said healthy forests with young trees absorb more carbon than older forests. The old-growth trees are better at storing carbon.
“We can sequester more carbon with active management rather than a hands-off approach,” she said.
Later this year, the Forest Service is expected to unveil a global warming-related forest management plan. It could involve planting additional acres, thinning existing stands and burning the leftover debris, or slash, to produce electricity. Kimbell said new boilers run cleaner on the scrap wood than oil- or gas-fired boilers can operate.
The timber industry, meanwhile, is trying to soften its image and emerge as a leading player in trying to rein in greenhouse gases.
“It’s common sense,” said Chris West, who heads the American Forest Resource Council based in Portland, Ore. “The No. 1 offset for carbon is planting trees. That’s what we are about.”
While cutting old trees releases some carbon, the wood is milled into lumber and other products that store carbon for up to 100 years, West said.
“The alternative is letting these old-growth trees be destroyed in some catastrophic event,” he said.
“It’s baloney,” said Mike Francis of the Wilderness Society. “The timber industry’s answer to everything is cut more trees.”
David Peterson, a research biologist with the U.S. Forest Service’s Pacific Wildland Fire Sciences Lab in Seattle, said global warming has changed everything when it comes to forest management.
“This is a whole new ballgame,” he said. “I call it management by experiment.”