Indirect land-use changes can overcome carbon savings from biofuels in Brazil
- aCenter for Environmental Systems Research, University of Kassel, 34109 Kassel, Germany;
- bInternational Max Planck Research School on Earth System Modelling, Max Planck Institute for Meteorology, 20146 Hamburg, Germany;
- c United Nations Environment Programme, Nairobi, Kenya;
- d Potsdam Institute for Climate Impact Research, 14412 Potsdam, Germany; and
- e Helmholtz-Centre for Environmental Research, 04318 Leipzig, Germany
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Edited by B. L. Turner, Arizona State University, Tempe, AZ, and approved January 8, 2010 (received for review July 2, 2009)

Abstract
The planned expansion of biofuel plantations in Brazil could potentially cause both direct and indirect land-use changes (e.g., biofuel plantations replace rangelands, which replace forests). In this study, we use a spatially explicit model to project land-use changes caused by that expansion in 2020, assuming that ethanol (biodiesel) production increases by 35 (4) x 109 liter in the 2003-2020 period. Our simulations show that direct land-use changes will have a small impact on carbon emissions because most biofuel plantations would replace rangeland areas. However, indirect land-use changes, especially those pushing the rangeland frontier into the Amazonian forests, could offset the carbon savings from biofuels. Sugarcane ethanol and soybean biodiesel each contribute to nearly half of the projected indirect deforestation of 121,970 km2 by 2020, creating a carbon debt that would take about 250 years to be repaid using these biofuels instead of fossil fuels. We also tested different crops that could serve as feedstock to fulfill Brazil’s biodiesel demand and found that oil palm would cause the least land-use changes and associated carbon debt. The modeled livestock density increases by 0.09 head per hectare. But a higher increase of 0.13 head per hectare in the average livestock density throughout the country could avoid the indirect land-use changes caused by biofuels (even with soybean as the biodiesel feedstock), while still fulfilling all food and bioenergy demands. We suggest that a closer collaboration or strengthened institutional link between the biofuel and cattle-ranching sectors in the coming years is crucial for effective carbon savings from biofuels in Brazil.
Footnotes
- 1To whom correspondence may be addressed. E-mail: lapola{at}usf.uni-kassel.de or dmlapola{at}yahoo.com.br.
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Author contributions: D.M.L., R.S., J.A., and J.A.P. designed research; D.M.L., and R. S. performed research; D.M.L., R.S., J.A., A.B., J.K., C.K., and J.A.P. analyzed data; and D.M.L. wrote the paper.
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The authors declare no conflict of interest.
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This article is a PNAS Direct Submission.
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This article contains supporting information online at www.pnas.org/cgi/content/full/0907318107/DCSupplemental.
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