The study estimates carbon impacts of bioenergy from ten biomass feedstock harvesting pathways feeding into three different production pathways. The harvesting pathways include forestry, agricultural residue, and dedicated energy crops. The production pathways are electricity generation, biochemical ethanol production, and thermochemical ethanol production. This is the first study to analyze climate implications of bioenergy from so-called reduced-impact logging. The analysis takes account of all major carbon sources and sinks, including soil carbon and nutrient losses from residue harvesting, to calculate carbon payback times, carbon intensities, and carbon savings, with the goal of identifying those pathways that have systematically smaller or larger climate impacts.