Bulk tankers being filled with sugar are a familiar sight along the docks at Santos, southern Brazil, where they have long been a symbol of the immense power of the country?s sugar cane producers.

The tankers have been joined recently by another symbol of the industry?s power: terminals for ethanol, a sugar cane product, whose arrival points to a shift with implications for the future of the world?s fuels. The world market for ethanol has grown from 28bn litres in 2000 to 49bn litres last year.