Life Cycle Assessment

A mobile conversion system based on beetle-kill feedstocks is likely to have significantly different greenhouse gas mitigation potential and general environmental footprint compared to more traditional biofuel supply chains.  Because the beetle-affected forests targeted are already undergoing massive disturbance, the detrimental effects on net ecosystem productivity (NEP) that have been identified as problematic in other forestry bioenergy systems are avoided; in fact, it may even be possible to improve upon the natural state of fire vulnerability and slow forest regeneration through targeted harvesting and managed regrowth.  On the other hand, the small scale and distributed nature of the conversion platform raises other challenges relating to the control of air and water pollutants during the conversion process.  The lifecycle assessment task will rigorously quantify the GHG and other environmental impacts of the full supply chain using the best available set of datasources, models, and accounting practices.

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Couple inventory estimates with carbon cycle models to dynamically estimate the full global warming impact of harvest

The atlas of beetle-affected forests produced in Task 1 will be used to parameterize an ecosystem model such as DayCent in order to predict changes in net ecosystem productivity under various salvage harvest scenarios as compared to the unmanaged system.  This carbon balance will then be used to compute the change in radiative forcing of the system over time, thus dynamically assessing the impacts of harvest disturbance and properly weighting the benefits of fossil fuel displacement against the resulting long-term changes in forest carbon dynamics.

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Integrate the results into a full lifecycle assessment framework

A full comparative lifecycle assessment will be conducted in order to understand the impacts of the system on climate, air & water quality, and human health.  The dynamic climate impacts of harvest will be integrated into an LCA tool such as GREET1 and combined with estimates of energy use and embodied emissions for the full supply chain as determined in Task 2.  Estimates of air and water pollutants generated at the point of conversion will be included, and a full suite of impact metric results presented.

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