An alternative approach to indirect land use change: Allocating greenhouse gas effects among different uses of land

Indirect land use change (iLUC) is hypothesized to occur when increasing demand for land due to bioenergy production displaces food and feed production onto new lands, thereby potentially producing large greenhouse gas emissions (GHG) during the land conversion event. Thus far, the totality of the projected iLUC effect has been assigned to biofuel production. In fact, multiple drivers of land use change exist and the resulting GHG releases should, in fairness, be allocated among these drivers. It seems more useful and intellectually rigorous to allocate potential land use change effects among these many drivers. This paper focuses on how to allocate the environmental consequences of iLUC to the multiple drivers through a function-oriented approach, namely human nutritional requirements for calories and protein. “Food versus Biofuel” issues can then be more usefully addressed as “Nutrition versus Biofuel” issues. Human beings actually have many choices in how we provide ourselves with adequate diets, and these choices have very different GHG and land use consequences. Therefore, in this paper, GHG assigned to iLUC is allocated between ethanol and human dietary preferences via a human nutrition-based method. Applying allocation approaches to iLUC lowers the estimated GHG of iLUC by up to 73% compared to GHG estimates in the GTAP model. For example, global warming intensity (GWI) of ethanol measured as CO2 equivalent becomes 58.2 g MJ−1, while GWI of ethanol calculated using GREET is 68.9 g MJ−1.

► Biofuel production is one of many factors driving indirect land use change (iLUC).
► A proper allocation of the consequences of iLUC among these drivers is required.
► There are many choices in how we provide ourselves nutritionally adequate diets.
►  Greenhouse gas emissions of iLUC are allocated via a human nutrition-based method.