Ethanol-driven car

I am taking an English lesson every Tuesday for an hour at a cafe. My teacher is a kind, gentle and modest American now living in Japan and married a Japanese woman. In the lessons, we often discuss about preserving global environment. The other day, he provided me with a piece of information concerning ethanol-driven car. The artcle's title is "More Brazil cars run on alcohol," sponsored by BBC online.

"Brazil's carmakers sold more vehicles adapted to run on alcohol last year than conventional petrol-driven models, motor industry figures show," said the article and was followed by the next passage "In all, 866,267 flex-fuel cars were sold in Brazil in 2005 against just 328,379 the year before, the Brazilian motor manufacturers' association Anfavea said."

I think it is a great step in an effort to improve global environment. Because ethanol is extracted from sugar-cane, consequently, there is no emission of carbon dioxide. However, my idea on this issue is that it is useful as an alternative energy for the time being, but there is a dangerous possibility that it can reduce sugar-cane fields as a source of food. I mean Brazil is a very large country and I see there is no such peril so far because sugar-cane is mainly planted in kind of offshore, deserted areas. But especially when people see it benefit from economical point of view, big industries like conglomerates may buy a lot of fields for sugar-cane, and it may end up depriving people in poverty countries of their foods. This is why I cannot 100% agree with the idea of using bioehanol as means of fuel, though it is effective for the time being.