A study explores the greenhouse gas (GHG) mitigation potential of biofuels. The use of biofuels to mitigate GHG emissions has been tied to potential negative effects of converting land to biofuel feedstock crop cultivation. Such potential effects include large up-front reductions in ecosystem carbon storage, indirect land use change, and opportunity costs of using land for biofuel feedstock instead of reforestation. To determine whether these drawbacks outweigh the benefits of biofuels, John Field and colleagues analyzed ecosystem and supply chain carbon flows for current and future biofuel systems compared with reforestation and grassland restoration at three case study sites in the United States. Conversion of secondary forests to biofuel production would incur large up-front reductions in carbon storage that would take decades to offset with current biofuel production methods. However, conversion of former cropland or pasture to biofuel production using current technology would achieve GHG mitigation comparable to that achieved by reforestation and 250% greater than that achieved by grassland restoration on the same land over the first 30 years. Plausible future improvements in crop yields and fuel-refining technology and incorporation of carbon capture and storage into the supply chain led to an estimated GHG mitigation potential 4 times and 15 times greater than that of reforestation and grassland restoration, respectively. The results support biofuels' climate mitigation potential, according to the authors.
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Article #19-20877: "Robust paths to net greenhouse gas mitigation and negative emissions via advanced biofuels," by John L. Field et al.
MEDIA CONTACT: John L. Field, Colorado State University, Fort Collins, CO; tel: 317-748-9792; e-mail: john.L.field@colostate.edu
Proceedings of the National Academy of Sciences