Making low-to-no-value forest residues, generated from the forest management practices associated with wildfire, pest, and disease control, into high value-added products has been an on-going focus for Forest Service research. This project studied the technology potential, product properties, and associated environmental impacts for woody biomass residue thermal conversion into activated carbon (AC) for gas purification and waste stream treatment. Commercial AC products are usually made from hard coal, a non-renewable material. The environmental benefits for woody biomass-based AC compared to coal-based AC were demonstrated using the life cycle assessment tool, an internationally accepted method. Less primary energy, especially fossil energy, was consumed for the woody biomass-based AC from cradle-to-gate compared to the coal-based AC. Consequentially, greenhouse gas emissions were reduced to more than half of the coal AC production for wood-based AC production. This was due to both the lower energy consumption and the biogenic carbon benefit when using the biomass residues both as feedstock and processing energy. In addition, the physical properties of the woody biomass-based AC were better than the commercially available coal-based AC for absorption. Such promising results from this study open up a potential high-value market for underutilized forest residues from U.S. forest restoration and wildfire suppression treatment.