Woody biomass is gaining increased attention as a potential source of renewable, carbon-neutral energy, but a new study is casting doubt on just how eco-friendly this fuel source really is.
In areas with dense forests, such as the western United States, producing energy from combustible forest materials has been touted as a way to reduce reliance on fossil fuels, improve forest health, and create green jobs.
In particular, Oregon Governor John Kitzhaber has pushed strongly for the development of this resource as a way of meeting his state’s renewable energy portfolio standard and revitalizing stagnant rural economies by incentivizing the growth of the biomass industry, pushing for classification of biomass as a carbon neutral energy source, and installing biomass burning furnaces in public schools. Federal and state subsidies aim to jumpstart energy production from biomass, and the EPA’s decision to wait three years before issuing rules concerning biomass emissions provides a stable window for growth in the short-term.
Despite the enthusiasm of biomass supporters, a study published last week in the journal Nature Climate Change shows that altering forest management practices in order to harvest and burn biomass in the western U.S. could increase carbon dioxide emissions from 2 to 14 percent over the next 20 years.
Forests act as a carbon sink, a reservoir that absorbs atmospheric carbon and sequesters it for long periods of time. The authors argue that burning biomass will release stored carbon faster than forests can reabsorb it. If this conclusion is accurate, it may have significant repercussions for the region’s small but expanding biomass industry and for policymakers seeking to curb carbon release.
Biomass advocates counter that, as forests regrow, they will regenerate the source of energy by recapturing all carbon originally sequestered in the burned biomass. While a recent University of Washington study supports this assertion by concluding biomass electricity production releases just 4 percent of the emissions created by burning coal, other studies have offered conflicting views. The discrepancies stem chiefly from disagreements about the timescale over which carbon emissions are considered and from differing projections of levels of biomass harvest.
The debate over the potential impact of biomass consumption on the carbon cycle highlights the difficulty of finding truly renewable, carbon neutral sources of energy and demonstrates the need for careful examination of research assessing new energy solutions. For now, Kitzhaber is standing by his support of biomass, citing its economic advantages. However, the new study will make it difficult for him to claim that biomass does not contribute to carbon emissions.
Although biomass may provide significant benefits for local economies, if the goal of energy policy is to curb carbon emissions, it may be best to promote other renewable energy sources. As regions work to find energy solutions that leverage locally available resources, environmental policymakers must answer vital questions about the often hazy effects of energy production on carbon release and storage. Unless additional research definitively quantifies the carbon costs or benefits of creating energy from biomass, policymakers will have to weigh the possibility that expanding this promising new resource could increase greenhouse gas emissions against the strong desire to reap its economic benefits.