Cited research: Atmos. Chem. Phys. 10, 5361–5370 (2010)

One in three ethanol molecules in the atmosphere originates from industrial sources and biofuels, scientists have calculated.

Ethanol derived from biomass has been widely promoted as a substitute for fossil fuels. But the overall impact of increased ethanol burning on atmospheric chemistry is largely unknown.

Vaishali Naik, then at Princeton University in New Jersey, and her colleagues used available observations and a global chemical-transport model to constrain the poorly defined global ethanol budget. They estimate that terrestrial plants produce about nine million tonnes per year, whereas five million tonnes come from anthropogenic sources, and a further half a million tonnes from biomass burning. However, the authors warn that the uncertainties are large, particularly for the ethanol concentrations over remote oceanic regions. Q.S.