How Corn Ethanol Destroys Rain Forests
At least according to a new story in Time, which is a blistering critique of our ethanol policies. It also documents the change of heart that has taken place among some prominent ethanol boosters.
In Brazil, for instance, only a tiny portion of the Amazon is being torn down to grow the sugarcane that fuels most Brazilian cars. More deforestation results from a chain reaction so vast it’s subtle: U.S. farmers are selling one-fifth of their corn to ethanol production, so U.S. soybean farmers are switching to corn, so Brazilian soybean farmers are expanding into cattle pastures, so Brazilian cattlemen are displaced to the Amazon. It’s the remorseless economics of commodities markets.
It is a sobering article, and well worth a read. It does contain some errors. First, the author repeats (and actually embellishes) the claim that ethanol “provide(s) 45% of Brazil’s fuel.” As I have shown previously, from actual energy usage statistics, it is about 17% of transportation fuel on a volumetric basis, and 10% on an energy equivalent basis. Second, on carbon emissions, the author mentions that the “gains approached 90% for more efficient fuels.” Important to note that while these 80 or 90% carbon emission reductions for next generation ethanol are liberally thrown around, they are all based on models. Nobody has actually demonstrated this. To demonstrate it requires a cellulosic ethanol plant that is highly integrated. The waste biomass must be used to provide power for the plant. There are a number of problems to be worked through – if not we would already have a cellulosic ethanol industry – but these numbers continue to be repeated as if they were demonstrated.
One other paragraph that I want to mention:
There isn’t much sugar in the Amazon. But my next stop was the Cerrado, south of the Amazon, an ecological jewel in its own right. The Amazon gets the ink, but the Cerrado is the world’s most biodiverse savanna, with 10,000 species of plants, nearly half of which are found nowhere else on earth, and more mammals than the African bush.
I haven’t seen a lot of mainstream coverage of the situation in the Cerrado, but I did write about it in the renewable diesel chapter that I recently contributed to a book that is still pending publication. When proponents say that sugarcane isn’t grown in the Amazon, they are right. But the story is much more complex than that.