Long Term Projections of Agricultural and Forestry Residues

Residues may act as a primary source of bioenergy; however the understanding of the drivers, constraints and costs of this resource is poor. This study projects long term global cost supply curves of the available potential by using consistent scenarios of agriculture and forestry production, livestock production and fuel use from a spatially explicit integrated assessment model. Particular attention is paid to the drivers and constraints. In the projections residue production is related to agricultural and forestry production and intensification, and the limiting effect of ecological and alternative uses of residues are accounted for. The results indicate that the theoretical potential is projected to increase from 120 EJ/yr today to approximately 150EJ/yr (depending on scenario) by 2100. However approximately 70% is not available, largely due to competing uses while most of the available potential can be supplied for less than 10$/GJ. Most of the available potential is located in Asia and North America due to the production of crops with high residue yields or socioeconomic conditions which limit alternative uses. Extensive agricultural production methods increase both the ecological requirement and costs.