I. The Importance of Emissions from Land Use Change

Lifecycle greenhouse gas calculations comparing biofuels and fossil fuels have traditionally focused on engineering calculations. They have carefully analyzed the respective emissions involved in producing a feedstock (through use of tractors and fertilizer for biofuels or mining efforts for crude oil), refining the feedstock into oil, transporting the products, and burning the fuel in the vehicle. Although these engineering calculations are important, biofuels are ultimately a land use decision. The potential of biofuels to reduce greenhouse gas emissions compared to fossil fuels originates with the capacity of land to remove carbon from the atmosphere. Biofuels have the theoretical potential to reduce greenhouse gas emissions because the growth of the feedstock takes the same amount of carbon out of the air that is released when the fuel is burned. By contrast, gasoline and diesel fuel take carbon out of the ground in the crude oil and release it to the air when the fuel is burned. Life-cycle analyses credit biofuels with this carbon removed from the atmosphere by growing the feedstock. In effect, they credit biofuels with the carbon benefit of the land used to grow them. Without this credi