Life Cycle Impacts of Forest Management and Bioenergy Production

The wood provided by forest management has the potential to provide many important energy products. Wood can provide replacements for gasoline and other liquid transportation fuels, heating products, plastics, and a wide range of industrial chemicals. There is great interest today in expanding the use of wood. However, the growing interest in wood energy has resulted in concerns about long-term forest sustainability and the role of forests in carbon mitigation and climate change.

This article provides an overview of forest bioenergy evaluations and a brief summary of the recent report Life Cycle Impacts of Forest Management and Wood Utilization on Carbon Mitigation: Knowns and Unknowns (Lippke et al. 2011). This recent report by Lippke et al. is the first to apply systematic life cycle analysis to forest bioenergy development and resulted in a number of key findings, including the following.

• Managed forests continually accumulate carbon and maintain stable carbon stocks. Photosynthesis turns carbon dioxide into solid wood in growing forests. Managed forests with healthy, growing trees maximize the rate of carbon capture, serve as a stable repository for carbon, and provide useful materials that store carbon outside of the forest.

• Sustainably managed forests are “better than carbon neutral” Forests managed for sustainability balance timber outputs with ecosystem needs and social values. Managed forests are considered sustainable if the outputs do not exceed growth and management results in a steady forest inventory over time. Forests absorb carbon dioxide from the atmosphere as they grow and carbon is stored in the wood produced. Wood products from the managed forest result in continued storage of carbon in useful materials outside of the forest. The carbon storage benefits of carbon pools outside of the forest combined with ongoing carbon absorption within the forest produces net carbon benefits that continue to accumulate over time.

• Carbon dioxide emissions from biomass power are 4% of emissions from coal power Life cycle assessment comparing electricity production from biomass versus coal shows an overwhelming emission reduction per unit of electricity produced. 

Wood from managed forests is already a widely used and important material. One of the reasons wood is so widely used is because it is renewable and, through responsible management, wood is produced while protecting other forest values. The growing interest in forest bioenergy creates new questions about forest management, and the findings of the recent report by Lippke et al. provide helpful information for evaluating the potential for sustainable bioenergy development.