Report

Biofuels for Transportation: A Climate Perspective

As the United States seeks to reduce greenhouse gas (GHG) emissions from motor vehicles and to lessen its dependence on imported oil, biofuels are gaining increasing attention as one possible solution. This paper offers an introduction to the current state of play for biofuels: the technologies used in their production, their GHG emissions, and associated policy issues.

The amount of emission reductions that can be achieved through the use of biofuels varies widely, depending on choices made at each step from feedstock selection and production through final fuel use. Technologies exist today to produce a wide variety of biofuels from a wide range of feedstocks. However, currently commercial options are limited to ethanol made from cornstarch or sugarcane, and biodiesel made from soybean or palm oil seeds. Current research and development focuses on lowering biofuel costs, GHG emissions, and land and water resource needs, and on improving compatibility with fuel distribution systems and vehicle engines. Policy priorities should be aligned with these R&D objectives as well as with other policies addressing climate, agriculture, forestlands and international trade.

The critical issue when considering the climate benefits of biofuels is each fuel's GHG profile—not whether it is “renewable” or “fossil-fuel”-based. Also, vehicle efficiency is especially important for biofuels because less overall fuel demand means less competition with other uses for land and biomass. Therefore, policies to encourage further development and use of biofuels for climate-related purposes should focus on their GHG profiles and on increased vehicle efficiency. In addition to climate change and energy security, the opportunity to support the agricultural sector is an extremely important and powerful motivation for pursuing biofuels worldwide. However, any benefits to the agricultural sector must be weighed against impacts on food prices and land use, both of which are also major international concerns.

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