Major findings of The Nature Conservancy/University of Minnesota study on land clearing and the biofuel “carbon debt” include:
- Converting rainforests, peatlands, savannas, or grasslands to produce biofuels in Brazil, Southeast Asia, and the United States creates a ‘biofuel carbon debt’ by releasing 17 to 420 times more carbon dioxide than the fossil fuels they replace.
- Converting lowland tropical rainforests in Indonesia and Malaysia to palm biodiesel would result in a biofuel carbon dept that would take approximately 86 years to repay.
- Converting tropical peatland rainforest with an average depth (3 meters) could incur a biofuel carbon debt that would take more than 840 years to repay.
- Soybean biodiesel produced on converted Amazonian rainforest would incur a biofuel carbon debt that would require approximately 320 years to repay.
- Sugarcane ethanol produced on Cerrado sensu stricto, which is the wetter and more productive end of this woodland-savanna biome, would incur a biofuel carbon debt that would require approximately 17 years to repay.
- Soybean biodiesel from the drier, less productive grass-dominated end of the Cerrado biome would incur a biofuel carbon debt that would require 27 years to repay.
- For US Central grassland on farmland that has been enrolled in the United States Conservation Reserve Program for 15 years, converting it to corn ethanol production creates a biofuel carbon debt that would take approximately 48 years to repay.
- The analyses suggests that biofuels produced on converted lands could, for long periods of time, be greater net emitters of greenhouse gasses than the fossil fuels they typically displace.
- For current or developing biofuel technologies, any strategy to reduce greenhouse gas emissions that causes land conversion from native ecosystems to cropland is likely to be counterproductive.
