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Unfortunately, data on the installation and use of pollution control equipment at our two sample maquiladora plants is limited. While the two plants claim to use emissions abatement devices, regulatory inspection and monitoring data is not available, and there is no easy way of verifying these claims. To account for this issue, we present estimates of health damages given: (i) emissions that would result if the plants used no pollution control devices whatsoever, and (ii) emissions that would result if they used all of the pollution control equipment that is standard in U.S. plants.3 Based on the. | nature climate change LETTERS PUBLISHED ONLINE 11 DECEMBER 2011 DOI 10.1038 NCLIMATE1325 Increased estimates of air-pollution emissions from Brazilian sugar-cane ethanol C-C. Tsao1 J. E. Campbell1 M. Mena-Carrasco2 S. N. Spak3 G. R. Carmichael3 and Y. Chen1 Accelerating biofuel production has been promoted as an opportunity to enhance energy security offset greenhousegas 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. Air-pollutant emissions from biofuel production and combustion may have significant impacts on climate and air quality. The change in vehicle emissions that would result from a large-scale conversion from gasoline to E85 a blend of up to 85 ethanol with gasoline or another hydrocarbon in the United States could have significant health consequences by increasing tropospheric ozone .
