Amazon rainforest will bear cost of biofuel policies in Brazil
By Rhett A. Butler
"Business-as-usual agricultural expansion to meet biofuel production targets for 2020 will take a heavy toll on Brazil's Amazon rainforest in coming years, undermining the potential emissions savings of transitioning from fossil fuels to biofuels, warns a new paper published in the Proceedings of the National Academy of Sciences (PNAS). The research suggests that intensification of cattle ranching, combined with efforts to promote high-yielding oil crops like oil palm could lessen forecast greenhouse gas emissions from indirect land use in the region.
Conducting a spatially-explicit analysis of potential land-use change from biofuel feedstock expansion in Brazil, David M. Lapola of the University of Kassel (Germany) and colleagues find that while relatively little forest land will be directly converted for biofuel production, large swathes of rainforest and cerrado will be indirectly impacted through displacement of cattle ranching, presently the dominant form of land use in the Brazilian Amazon.
"To fill the biofuel production targets for 2020, sugarcane would require an additional 57,200 [square kilometers] and soybean an additional 108,100 sq km. Roughly 88% of this expansion (145,700 sq km) would take place in areas previously used as rangeland," the authors write. "In our simulations, direct deforestation is only caused by soybean biodiesel and amounts to only 1,800 sq km of forest and 2,000 sq km of woody savanna."
A carbon payback time of four years would be needed to compensate for direct emissions from conversion for cane relative to emissions from fossil fuels. The payback for soy biodiesel would be 35 years, according to the research.
But factoring in indirect land use — cattle ranching displaced to forest lands by cropland expansion — dramatically extends the amount of time needed for emissions savings from biofuel production (relative to fossil fuel use) to compensate for emissions from deforestation: by 40 years for cane ethanol and 211 years for soy biodiesel.
"Indirect land-use change could considerably compromise the GHG savings from growing biofuels, mainly by pushing rangeland frontier into the Amazon forest and Brazilian Cerrado savanna," Lapola and colleagues write. "In our simulations, there is an expansion of 121,970 sq km of rangeland into forest areas, and 46,000 sq km into other native habitats, due to the expansion of biofuel croplands."
"Sugarcane ethanol and soybean biodiesel would be responsible for 41% and 59% of this indirect deforestation, respectively."
The authors suggest that planting oil palm instead of sugarcane or soy on pasture lands would result in some direct deforestation (300 sq km) but significantly reduce emissions from indirect land-use change due to the crop's substantially higher oil yield.
"[We] 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," they write. "Because of its high oil yield, oil palm would need only 4,200 sq km to fulfill the 2020 demand for biodiesel in Brazil. In comparison, 108,100 sq km would be needed for soybean."
Lapola and colleagues also note that restoring the productivity of Brazil's 290,000 sq km of degraded and abandoned rangeland could reduce pressure to convert native forests, thereby mitigating potential emissions.
Lapola and colleagues conclude by calling for "an increased interconnection between land-use sectors."
"We argue that to avoid the undesired indirect land-use change by biofuels presented here, strategies for cooperation between the cattle ranching and biofuel-growing sectors should be implemented by the biofuel sector (based on the sector’s own interest in minimizing GHG emissions), and institutional links between these two sectors should be strengthened by the government."
"In other words, biofuel organizations and the government should support initiatives toward modernization of the cattle ranching sector to guarantee that the production of biofuels is not causing ILUC, which would compromise the efficacy (in terms of carbon savings) of their own product. Such a requirement should also be considered as a standard for the production of sustainable biofuels."
Lapola et al. Indirect land-use changes can overcome carbon savings from biofuels in Brazil. PNAS Early Edition for the week of Feb 8, 2010. www.pnas.org/cgi/doi/10.1073/pnas.0907318107 "