Food, fuel, fibre and faces to feed. Simulation studies of land use change for sustainable development in the 21st century

Abstract

A simulation model is employed to study the potential for greenhouse gas mitigation of biomass carbon storage in both long rotation forestry ‘sequestration’ and indirectly, through biofuel production. The model simulates competition in the allocation of a global fixed supply of nonforest, non-barren land to wilderness (yielding biodiversity benefits) and to use in conventional farming, in medium-term sequestration forestry (as a carbon buffer stock) and in biofuel production. A set of non-linear ordinary differential equations is solved simultaneously to yield time profiles for land rent, fossil fuel producer prices, carbon fuel selling prices and for the carbon level in the atmosphere. Rent rises in a non-linear manner as the land constraint is approached. A carbon tax provides a wedge between fossil fuel prices and consumer prices, with its revenue dedicated to covering the costs of biofuel production and of the buffer stock. The carbon flow effects of absorption by forestry and biofuel production and of emissions from using fuel, together with the effects of natural absorption, combine to yield a time profile of atmospheric carbon. The model is driven by user selection of policy choices in the time profiles of land use for sequestration and for biofuel. Reductions of carbon levels towards preindustrial levels by the year 2050 appear to be feasible under sufficiently vigorous policy. Matlab software is employed and the full model coding is available from the author.