Economic Insights Required for Using Lifecycle Analysis for Policy Decisions
通过整合土地、粮食和燃料市场的模型，研究发现生物燃料扩张导致的温室气体排放变化随经济中生物燃料数量和政策类型显著不同，对生命周期分析有重要启示。
We develop an analytic and numerical model that integrates land, food and fuel markets and is linked with a sectoral emissions model to examine how the amount of biofuel in the economy impacts the lifecycle emissions of a biofuel under different policies. Our central finding is that the change in GHG emissions due to a unit expansion in biofuel will vary dramatically in the amount of biofuel in the economy and with the policy driving the expansion. The emissions from a unit expansion in corn ethanol due to a blend mandate fall from 12 gCO2e/MJ to 3 gCO2e/MJ, as the quantity of ethanol in the economy increases from 6 to 15 billion gallons. For an input subsidy, emissions due to a unit of ethanol increase from 15 gCO2e/MJ to 26 gCO2e/MJ over the same increase in ethanol. We discuss the implications of these results for lifecycle analysis.