Millions of acres of U.S. forest lands are carpeted with stands of unsightly reddish-brown trees that were killed by voracious beetles the size of rice grains. A $10 million, five-year research program launched this week aims to determine if the beetle-killed trees can be turned into biofuel for cars and trucks without breaking the bank or exacerbating climate change, which is aiding the beetle mania.
"A crucial thing with biofuels is that we understand just how much greenhouse gases do we really offset. Because obviously if we use lots of fossil fuels or we cause lots of emissions in producing the biofuels, then we are really not gaining as much as we might hope to," Keith Paustain, a soil ecologist who is leading the project at Colorado State University in Fort Collins, told NBC News.
The idea of using the dead trees as feedstock for bioenergy sounds promising. The trees are already there, which means they don't require cultivation and thus skirt the food-versus-fuel debate that has clouded the push for corn-based ethanol, for example. The trees are also tinder for fueling forest fires that could prove catastrophic to mountain communities. Removing the trees reduces wildfire risk.
However, many of these trees are located in difficult-to-reach terrain and far from industrial facilities that could turn them into fuel, which adds to the harvest and transportation costs. Other concerns include the environmental and ecological impacts of removing the trees as well as potential local policy barriers.
"The whole idea from the standpoint of the research on this is not to advocate for or against exploitation in any particular place, but do the research," explained Paustain.
Resource sustainability questioned
The bioenergy project is funded by the U.S. Department of Agriculture's National Institute of Food and Agriculture, which views development of a biofuels industry around beetle-killed trees as a way to fight the infestation while creating jobs and renewable energy. The question is whether such an industry can be economically viable and environmentally sustainable.
"The prominent issue that pops right up from the beginning is the question of long-term viability," Nathanael Greene, an energy policy and biofuels expert at the Natural Resources Defense Council, an environmental group in New York, told NBC News. That's because even though the beetle-kill is widespread, it affects a limited number of trees. Once they are harvested, the supply is gone.
"And then what?" he asked. "And that 'then what?' would make me really nervous unless someone had a really good answer." The concern is that the refineries that convert the biomass to biofuel are typically massive, have 30-to-50-year lifetimes, and thus need a steady supply of feedstock to remain economically viable.
To address this concern, the beetle-kill biofuel project will consider mini-refineries being built by Colorado-based Cool Planet Energy Systems. The company's modular system can be tailored to the feedstock available, and set up close to the beetle-killed trees. When all the trees are harvested, they can pack up the system and move to the next infested forest.
"The episodic nature of the beetle kill is a challenge," Paustain noted. "That's why you need this kind of scalable conversion technology."
The technology involves burning the dead trees in the absence of oxygen to generate hydrocarbon fuels and a byproduct known as biochar that can be added to agricultural lands to help capture carbon dioxide from the air and retain moisture, thus enhancing soil quality. According to Greene, this type of model stands a chance of working long term.
Other concerns swirl around the determining who and what this project will benefit. The myriad interests include an industry and government pushing for reliable, domestic sources of fuel; communities pushing for reduced fire risk; and a global interest in reducing the load of greenhouse gases emitted to the atmosphere.
"Sometimes those goals can be very synergistic," noted Greene. "But it is not a given."
More often than not, he added, these types of projects wind up adding carbon to the atmosphere, and thus exacerbating global climate change. "So you really have to be sure that you are providing a real forest health and biodiversity benefit to justify that."
John Roach is a contributing writer for NBC News. To learn more about him, visit his website.