RIO DE JANEIRO, May 9 (IPS) - Recent efforts by President Luiz Inácio Lula da Silva to clearly mark the difference between Brazilian ethanol and the agrofuels produced by the United States are an admission that signing an agreement with Washington to promote a global bioethanol market was a serious political mistake, say analysts.

Brazilian fuel alcohol, distilled from sugarcane, has been used as a partial substitute for gasoline in the country for 30 years, and makes an acknowledged contribution to mitigating global warming because it emits less greenhouse gases than fossil fuels.

However, in recent months a flood of criticism has engulfed all biofuels, because of their role in helping to drive up food prices. Jean Ziegler, former United Nations special rapporteur on the right to food, called the conversion of food crops into biofuels "a crime against humanity."

A memorandum of understanding, signed in March 2007, for cooperation between Brazil and the United States in promoting ethanol production in tropical countries, as well as technology transfer and definition of technical standards, united the biofuels of both countries in terms of their international image.

Negative global perceptions of President George W. Bush and his government's war in Iraq may have contributed to the unpopularity of U.S. ethanol, with Brazil's alcohol being tarred with the same brush.

In January 2007, Bush announced a bold plan to cut gasoline consumption by 20 percent in the United States within 10 years, through the use of substitutes, mainly ethanol.

Dire food shortages that began last year have sparked violent protests in dozens of poor countries, and have led to widespread accusations that ethanol and biodiesel are worsening the food crisis.