Land-based mitigation in climate stabilization

Abstract

This paper evaluates the role of land in long-run climate stabilization mitigation scenarios. The details of land modeling for common stabilization policy scenarios are, for the first time, presented, contrasted, and assessed. While we find significant differences in approaches across modeling platforms, all the approaches conclude that land based mitigation – agriculture, forestry, and biomass liquid and solid energy substitutes – could be a steady and significant part of the cost-effective portfolio of mitigation strategies; thereby, reducing stabilization cost and increasing flexibility for achieving more aggressive climate targets. However, large fossil fuel emissions reductions are still required, and there are substantial uncertainties, with little agreement about abatement magnitudes. Across the scenarios, land mitigation options contribute approximately 100 to 340 GtC equivalent abatement over the century, 15 to 40% of the total required for stabilization, with bio-energy providing up to 15% of total primary energy. Long-run land climate modeling is rapidly evolving with critical challenges to address. In characterizing current capability, this paper hopes to stimulate future research and the next generation of land modeling and provide a point of comparison for energy and climate policies considering bio-energy, reduced deforestation and degradation, and cost containment.