Fig. 1

Life cycle GHG emissions by process associated with the production of bioethanol from willow. The number on each bar is the net GHG emissions. Negative values indicate net carbon sequestration from the atmosphere and positive values are net emissions to the atmosphere. For each scenario name, the first letter indicates the land use class before willow was planted (C-cropland, G-grassland, and M-mix of 11.3% G and 88.7% C), the second letter for energy source (B-biomass), and the third letter for harvest season (S-summer and W-winter). The dashed line represents the life cycle GHG emissions of 1 MJ of gasoline