Demand for ethanol made from sugar cane is booming in Brazil, where it is used to make gasohol — the country's most common car fuel, consisting of 23 per cent ethanol.

Key to this boom are the country's 'flex-fuel' cars, introduced in 2003, which can be run on mixtures of petrol and ethanol, allowing drivers to choose their fuel depending on local prices. These now account for well over half of Brazil's new cars, reports Emma Marris.

Producing ethanol from sugar cane has been touted for being greener and requiring fewer inputs — for example fertilizer — than other crops, such as corn.

And growing sugar cane is easy in sunny Brazil. It only needs to be replanted every five years, making it the cheapest ethanol in the world.

There are uncertainties about environmental costs and sustainability, but as the market continues to expand, there is increasing interest from other countries to cash in on the advantages of sugar cane.

Link to full article in Nature

Reference: Nature 444, 7120 (2006)