The role of sustainability and life cycle thinking in U.S. biofuels policies.

A comprehensive review of the U.S. federal biofuel-related policies, from 1955 to 2012, was conducted to examine the progression of life cycle thinking within the policies. Over 1300 past and present federal and state biofuel laws and incentives were analyzed to identify the establishment of Life-cycle thinking (LCT) in the biofuel policies. The policies were searched for search terms representing the three themes: life cycle assessment, environmental impact and sustainability. LCT in policies was first seen in the Renewable Fuel Standard under the Energy Independence and Security Act of 2007, where life-cycle greenhouse gas emissions reduction of biofuels was required. Existing U.S. biofuel policies were also characterized to define types of policy as tax incentive, grants, mandate, etc. The results suggested that climate change or energy incentives, air quality or emissions, etc. should be more emphasized in fuel legislation for a continuous improvement of biofuels industry. Only 13% of both the federal and state policies reviewed in this study employed some aspect of LCT. Policies that incorporate LCT often only focused on greenhouse gas emissions; policies should include other environmental impacts to avoid any environmental tradeoffs and unintended consequences from biofuel production.