for National Geographic News
In Brazil ethanol has become economically competitive with gasoline, and the country's biofuels program could serve as a world model for producing sustainable energy, officials say.
South America's largest country is the world's reigning ethanol king, producing 4.4 billion gallons (16.5 billion liters) of the biofuel from sugarcane each year, on average.
Biofuel is widely considered a way to reduce greenhouse gases from fossil fuel use and thereby reduce human-caused global warming.
(Related news: "Global Warming "Very Likely" Caused by Humans, World Climate Experts Say" [February 2, 2007].)
Brazil's sugarcane-based ethanol program is "appropriate for replication in many countries," writes José Goldemberg, secretary of the environment for the Brazilian state of São Paulo, in a perspective article in this week's issue of the journal Science.
But an unregulated biofuels boom in Brazil could mean bust for the Amazon rain forest and a vast savanna ecosystem known as the Cerrado, environmentalists warn.
Expanding large-scale agriculture to grow sugarcane, critics say, will worsen the loss of species diversity, water-quality problems, and habitat fragmentation in some of the world's most biologically diverse regions.
"The primary concern is that the biofuels push will directly or indirectly increase the loss to Brazil's remaining natural high biodiversity areas, such as the Cerrado," said John Buchanan, a senior director for the U.S.-based nonprofit Conservation International.
Sugar Farming Not So Sweet?
The 740,100-square-mile (1.9-million-square-kilometer) Cerrado region is South America's largest savanna—one of the richest in the world, in terms of bird, reptile, fish, and insect species.
According to a study published last year in the journal Conservation Biology, more than 50 percent of the Cerrado has already been transformed into pastureland, causing soil erosion, biodiversity loss, fragmentation, and the spread of nonnative grasses.
"Most of the expansion required will affect the Cerrado ecosystem and the Amazon, which are already being destroyed because of cattle ranching and soybean farming," said Leonardo Lacerda of the Brazilian chapter of the international conservation group WWF.
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