Federal forests could be tasked with fighting global warming

View full sizeMatthew Preusch/The OregonianMark Schulze, forest director at the H.J. Andrews Experimental Forest, tours a stand of old growth timber at the public forest east of Eugene. Scientists are performing tests at the Andrews to better understand how Oregon's forests absorb and store heat-trapping gasses from the atmosphere.If forests are the planet's lungs, few breathe deeper than those in Oregon. 

The rain-soaked tangle of trees on the west slope of the Cascades and eastern Ponderosa pine forests draw in carbon dioxide and store it in timber, plants and soil. These forests absorb and store up to half of the emissions from Oregon's cars and power plants, according to a calculation by Oregon State University. 

Now some in Congress and the administration are trying to find a way for the government to be paid for the use federal forests play in pulling heat-trapping gasses like carbon dioxide from the atmosphere. That might involve logging, thinning or no cutting at all. It matters here, however, because federal forests make up the majority of Oregon timberlands. 

"No doubt, this is one way to bring considerable investment to the nation's forests," Tom Tidwell, the chief of the U.S. Forest Service said this month. "There are also some concerns and some questions." 

Not least of which is: How would the government change how it treats public forests – which already provide timber, wildlife habitat, clean water and recreation – if they were put to work slowing climate change? 

Answer: It might change in several ways, or not at all. At one extreme, conservationists argue a complete halt to west side logging would equal in carbon savings the removal all Oregon's automobiles from roadways. At the other, logging advocates say cut more often and use the wood, which stores carbon until it rots, and plant fast-growing young forests. 

View full sizeIf the science isn't settled, the politics is equally fractious. 

Oregon Senator Ron Wyden and others are now pushing to have federal forests included as a source of carbon offsets in a so-called cap and trade program to limit greenhouse gas emissions. 

"In my view, it is time to manage the nation's forests to address climate change," Wyden, an Oregon democrat, said this month. A cap and trade program would set limits on how much carbon dioxide a facility like a coal plant emits. If the plant exceeds those limits, it could offset the excess pollution by purchasing a credit from a project elsewhere that captures carbon. 

Owners of private forests are already involved in voluntary carbon trading markets on a small scale, doing things like allow more time between harvests to increase carbon storage. But a national cap and trade law would greatly expand the interest in offsets. 

"The Department of Interior thinks there are incredible opportunities to include federal lands offsets into a cap and trade program," said Kit Batten, science advisor for the department, which controls Bureau of Land Managementforests in western Oregon, told a senate subcommittee chaired by Wyden this month. 

The back and forth at that hearing revealed some of the complexity involved in what Wyden is proposing. Sen. John Barrasso, a Republican from Wyoming, said to maximize carbon capture, forests should be logged and turned into lumber, which would store the carbon in the form of two-by-fours and other long-lived wood products. 

"Logging some or all of this material might be wise in terms of carbon and the future," Barrasso said. The Wyoming senator's view is supported by analysis done by Elaine Oneil at the University of Washington's forestry school. 

Oneil said more carbon is released into the atmosphere by producing wood alternatives like concrete and steel, outweighing the carbon benefit of leaving forests standing."The best thing to do, in terms of a carbon benefit, is to manage these forests on fairly rapid rotations," Oneil said of Oregon's wet, west-side forests. 

Conservationists, on the other hand, argue that to maximize carbon storage you should let old forests stand; let young trees grow longer between harvests; don't clear-cut; and, where appropriate, thin overcrowded forests to avoid large fires that release lots of carbon in the atmosphere. 

"Stopping logging in western Oregon alone would be the equivalent of taking every Oregon car off the road," said Erik Fernandez of the group Oregon Wild. 

Conservationists base their arguments on recent studies by scientists like Oregon State University's Mark Harmon that conclude forests like those that cover half of Oregon should generally be left alone if you want to maximize their carbon storage. 

Harmon likes to compare forests to leaky buckets for carbon. The forest ecologist says forests store carbon like a bucket with holes in it stores water. So long as more is entering the bucket than is leaving through the holes, it's achieved net positive carbon storage. 

To increase the amount of carbon a forest holds, you can try to plug some of the leaks or increase how much is coming in. Carbon leaks through processes like decomposition, fire and logging. So letting more time pass between logging operations, for instance, lessens the leakage. 

Even so, "we won't have as much carbon storage as if we never touched it again," Harmon said. "That's the least leaky bucket we could design, even with fires." 

There are exceptions, others aregue. In dry, low-elevation Ponderosa pine forests east of the Cascades. scientists say thinning out of small trees could help. Decades of fire suppression left many of these forests filled with thickets of small and medium-sized trees, which could cause uncharacteristically large and intense wildfires. 

Though thinning out these stands can release carbon in the short term, it could increase the forest's ability to capture and store more of the greenhouse gas in the future, said Matthew Hurteau,  a forest carbon expert at Northern Arizona University in Flagstaff. 

"You are structuring the forest so that when you have a fire it happens in a way that more trees survive," Hurteau said. 

And Wyden and others hope the thinned material can be used as a source of biofuels or fodder for rural mills."There is a sense that this makes sense all around," Wyden said. 

The scientific debate is only part of the challenge. More problems arise when you try to put a dollar value on carbon storage. 

The Forest Service has no estimate on what the revenue potential could be for carbon offsets from forests it manages. 

For one, it's difficult to measure just how much carbon an acre of forest is absorbing and storing. And credits only count if the carbon captured is above and beyond what would be happening with business as usual, a concept called additionality. 

For Northwest federal lands, business as usual is already capturing and storing a lot of carbon. Al Gore, the most high-profile figure warning against man-made global warming, said as much on a recent trip to Portland. "I think the balance we struck back in the day with the Northwest Forest Plan is still in broad outline the appropriate balance to strike," the former vice president said. 

And some at the Forest Service are worried that if vast federal lands provide offsets, it could diminish the revenue opportunities on private lands, which economic pressures can push towards development. 

"I don't want to do anything on the public lands that's going to reduce our chance to be successful with that on private lands," Joel Holtrop, the agency's deputy chief said at a recent symposium on forest carbon. "It's a complex question."

-- Matthew Preusch