HR: 16:45h
AN: B44B-04 INVITED    [Abstracts]
TI: Will Biofuel Expansion Mitigate Climate Change?
AU: * Lobell, D
EM: dlobell@llnl.gov
AF: Lawrence Livermore National Lab, 7000 East Ave, Livermore, CA 94550,
AU: Campbell, E
EM: campbell@stanford.edu
AF: Carnegie Institution, 260 Panama St, stanford, ca 94305,
AU: Field, C
EM: cfield@globalecology.stanford.edu
AF: Carnegie Institution, 260 Panama St, stanford, ca 94305,
AB: For biofuels to displace a substantial fraction of fossil fuel consumption, production will have to be scaled up at least an order of magnitude over current levels. The net effect of this expansion on climate will depend not only on the energy inputs and outputs of biofuel production, but also on the climate effects of land-use changes associated with the expansion. We distinguish three types of biofuel related land-cover conversions ­ (1) food crop to biofuels, (2) forest to biofuels, and (3) marginal grassland to biofuels ­ and discuss the potential production and net climate impact for each. We argue that the first two of these may contribute to energy supply but are unlikely to produce significant climate benefits over first 50 years of production, with only marginal lands offering a climate benefit. Using historical land-use datasets to define the current extent of marginal or degraded grasslands, and maps of native net primary production and food crop yield trends to estimate their potential yields, we estimate that ~1 Pg C per year can be attained on these lands, which would provide just 3% of current global energy needs. In addition, we discuss other societal and ecosystem impacts of biofuel expansion, and how these impacts compare to those projected for climate change itself.
DE: 0402 Agricultural systems
DE: 0410 Biodiversity
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
DE: 0429 Climate dynamics (1620)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting