Modeling alternative policies for forestry and agricultural GHG mitigation: Allowances vs. offsets

century under a wide range of alternative CO2 equivalent (CO2eq) prices for allowances and offsets. Mitigation potential is reported as changes from baseline trends, starting in 2010 and projected out 100 years in five year time steps. Climate scenarios include constant prices of 1, 5, 15, 30, and 50 per tonne CO2eq with multiple combinations of different prices in the allowance and offset markets, as well as three rising price scenarios chosen to reflect the assumptions that the market price for offsets and abatement could increase over the course of a policy. These rising price scenarios provide valuable insight on the potential changes in landowner behavior and a delay of action that could occur in this forward looking model. This study also investigates the cost and GHG implications of limiting or even excluding certain mitigation options from the suite of offsets or allowances potentially available from this sector. Results FASOM-GHG v2 recently was updated and is currently being applied in analyses of renewable fuels mandates and comprehensive climate policies proposed by the U. S. Congress. Preliminary results indicate that there is significant mitigation potential from both conventional offsets and allowances for biofuels when the GHG mitigation price is 15/tCO2eq or more (~500 TgCO2eq/yr). Limiting the available credits from traditional offset options such as afforestation and soil carbon sequestration reduces the mitigation available from this sector, however, the land and GHG mitigation from liquid biofuels and bioelectricity that qualify as allowances expand as their economic potential is improved. Thus, our results show that land use allocation and mitigation potential is quite sensitive to the specifics of the policy. We are currently engaged in model runs and verification of results that will expand the level and detail of the results beyond this preliminary stage including several different price paths and offset availability Conclusions: In this study, we apply one of the most comprehensive forestry, agriculture, and land use models of the U. S. available to explore the implications of alternative GHG mitigation policy design. Our findings in this study will provide valuable information and insights to policymakers making decisions regarding the treatment of these sectors in national climate policy legislation and international agreements.