Study – Think Wood Pellets are Green? Think Again

NRDC, May 2015: “Biomass is often described as a clean, renewable fuel and a greener alternative to coal and other fossil fuels for producing electricity. But recent science shows that many forms of biomass—especially from forests—produce higher carbon emissions compared to fossil fuels. In particular, a growing body of peer-reviewed, scientific studies shows that burning wood from whole trees in power plants to produce electricity can increase carbon emissions relative to fossil fuels for many decades—anywhere from 35 to 100 years. This time period is significant: climate policy imperatives require dramatic short-term reductions in greenhouse gases, and these emissions will persist in the atmosphere well past the time when significant reductions are needed. Unfortunately, the biomass wood pellet industry in the southeastern United States is expanding rapidly. Wood pellet exports from the United States doubled from 1.6 million tons in 2012 to 3.2 million tons in 2013, and they are expected to reach 5.7 million tons in 2015. This growth is driven largely by exports to Europe in response to flawed policy incentives on renewable resources that regard all biomass as carbon neutral. Although recent science shows that many forms of forest biomass are high-carbon sources of fuel, under the right circumstances, true wood waste could serve as a low-carbon option for producing pellets. For example, sawdust and chips from sawmills that would otherwise quickly decompose and release carbon anyway—can be a low-carbon source. On the other hand, burning whole trees can produce higher carbon emissions than coal, and this elevated CO2 level with respect to coal can persist in the atmosphere for decades. Therefore, the composition of wood pellets matters greatly: the amount of whole trees used in wood pellets can have a significant impact on the estimated carbon emissions of this fuel source.”