April 20, 2012
Scientists evaluating large-scale bioenergy production from forest biomass concluded that it is unsustainable and will increase greenhouse gas emissions. The group of international researchers outlined their analysis in the journal Global Biology/Bioenergy.
They expressed several concerns about the viability of large-scale biomass, and determined that bioenergy is not carbon-neutral.
Items cited by the group include:
- Lost carbon sequestration by forests because of biomass production
- The economic viability of biofuels may depend on government mandates or subsidies
- A higher demand for biomass from forests will increase prices for biomass
- Negative impacts are possible on vegetation, soil fertility, water and ecosystem diversity
- The potential exists for increased fertilizer use
A major increase in the biomass production industry, they concluded, would result in shorter tree rotations, younger forests, depleted soil nutrients, increased risk of erosion, and loss of forest biodiversity and function.
Colorado biomass potential
In Colorado, the mountain pine beetle infestation suggests a large supply of forest fuels for bioenergy, but the dynamics of forest bioenery production are complex. Kurt Mackes, senior research scientist at Colorado State University spoke at a panel session at the Rocky Mountain Forest Restoration & Bioenergy Summit recently and described the barriers and challenges to forest biomass production in Colorado. He said a large percentage of beetle kill trees will go unutilized
From commercially less-valuable smaller tree sizes in state forests to a general lack of infrastructure to support biomass production in Colorado, near-term prospects for the industry, beyond small-scale local projects, seem modest.
Large-scale biomass
The analysis published in Global Biology/Bioenergy was based on a theoretical, significant increase in energy from forest biomass to 20 percent or more of current global primary energy supply.
A major initiative is now under way in the Pacific Northwest to study forest biomass and produce aviation fuel while thinning regional forests. However, it is much less ambitious than the scenarios studied in the new analysis.
The study was led by the Max-Planck Institute for Biogeochemistry in Germany, Oregon State University and other universities in Switzerland, Austria and France. It is available online at http://bit.ly/HySkxu.