California Biopower Impacts Project: Climate and Air Pollution Impacts of Generating Biopower from Forest Residues in California

California faces crisis conditions on its forested landscapes. A century of aggressive logging and fire suppression in combination with conditions exacerbated by climate change have created an ongoing ecological, economic, and public health emergency. Between ongoing commercial harvest on California’s working forestlands and the increasing number of acres the state treats each year for fire risk reduction and carbon sequestration, California forests generate millions of tons of woody residues annually that are typically left or burned in the field, impacting air quality.

State policymakers have turned to bioelectricity generation as a key market for woody biomass in the hope that it can support sustainable forest management activities while also providing low-carbon renewable electricity. However, open questions surrounding the climate and air pollution performance of electricity generation from woody biomass have made it difficult to determine how best to manage the risks and opportunities posed by forest residues.

The California Biomass Residue Emissions Characterization (C-BREC) model offers a spatially-explicit Life Cycle Assessment framework to rigorously and transparently establish the climate and air pollution impacts of bioelectricity from forest residues in California. C-BREC has shown that the life cycle “carbon footprint” of biopower from residues of a majority of forest management activities ranges between that of solar photovoltaics and natural gas power. This variation stems largely from the heterogeneity in the fire and decay conditions these residues would encounter if left in the field. This report documents the methods and findings of the C-BREC model across recent forest treatments in California. C-BREC can be used to identify the locations and treatment types in which utilization of forestry residues offers climate and air pollution benefit and could be useful to state policymakers in shaping California’s energy and forest management policies going forward.

For more information about the C-BREC model, see schatzcenter.org/cbrec/.