Science magazine this week published an exchange between Vinod
Khosla, the venture capitalist who has invested a great deal in
alternative energy, and Timothy Searchinger and coauthor Richard
Houghton critiquing and defending the February 2008 study, “Use
of U.S. Croplands for Biofuels Increases Greenhouse Gases
Through Emissions from Land-Use Change” The exchange reveals
some of the nuances of indirect land use change arguments that
have not been addressed. Khosla’s comments raise two important
issues, allocation and system boundaries, though they go largely
unexplored. He writes, It is inaccurate and misleading to
allocate the cutting down of Brazilian rainforest, which is done
often for timber production, to biofuels use. The economic
signals driving biofuels or agricultural land-use changes are
different from the timber-driven economic signals driving land-
use change patterns. The deforestation estimates of Searchinger
et al. are appropriate for biodiesel production in the Far
East.” Deforestation in Mala