Controversy erupts around Brazilian ethanol study headlines

In Brazil, ethanol opponents are jumping on a headline which appeared in Nature Geoscience reading “Reduction in local ozone levels in urban Sao Paulo due to a shift from ethanol to gasoline use.” The study, conducted by Steve VanderGriend at the Urban Air Initiative, concluded that ozone levels reduced by 20% when drivers switched from ethanol to gasoline fuels.

However, as critics point out, Brazil’s ethanol is hydrous ethanol and their gasoline is E25; it remains true that emissions reduce when ethanol is added to gasoline. The study merely concludes that mid-level ethanol blends reduce emissions, not that ethanol increases emissions.

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