Increased estimates of air-pollution emissions from Brazilian sugar-cane ethanol
Author: ["C-C. Tsao","J. E. Campbell","M. Mena-Carrasco","S. N. Spak","G. R. Carmichael","Y. Chen"]
Publication: Nature Climate Change
CITE.CC academic search helps you expand the influence of your papers.
Abstract
Biofuels are often promoted as a way of mitigating climate change, but their impacts on climate and air quality remain uncertain. Estimates of air-pollutant emissions from the production and use of sugar-cane ethanol in Brazil indicate that this biofuel may have larger impacts on regional climate and human health than previously thought. Accelerating biofuel production has been promoted as an opportunity to enhance energy security, offset greenhouse-gas emissions and support rural economies. However, large uncertainties remain in the impacts of biofuels on air quality and climate1,2. Sugar-cane ethanol is one of the most widely used biofuels, and Brazil is its largest producer3. Here we use a life-cycle approach to produce spatially and temporally explicit estimates of air-pollutant emissions over the whole life cycle of sugar-cane ethanol in Brazil. We show that even in regions where pre-harvest field burning has been eliminated on half the croplands, regional emissions of air pollutants continue to increase owing to the expansion of sugar-cane growing areas, and burning continues to be the dominant life-cycle stage for emissions. Comparison of our estimates of burning-phase emissions with satellite estimates of burning in São Paulo state suggests that sugar-cane field burning is not fully accounted for in satellite-based inventories, owing to the small spatial scale of individual fires. Accounting for this effect leads to revised regional estimates of burned area that are four times greater than some previous estimates. Our revised emissions maps thus suggest that biofuels may have larger impacts on regional climate forcing and human health than previously thought.
Cite this article
Tsao, CC., Campbell, J., Mena-Carrasco, M. et al. Increased estimates of air-pollution emissions from Brazilian sugar-cane ethanol. Nature Clim Change 2, 53–57 (2012). https://doi.org/10.1038/nclimate1325
