By Madelin Kovacs

Biofuels have been held up by all three 2008 candidates for the U.S. Presidency as the best way for America to move forward in reducing our carbon emissions. But it is beginning to seem more and more likely that farming and production of biofuels is in fact responsible for more global warming than they are solving.In his feature article in TIME, “The Clean Energy Scam,” published March 27, 2008, Michael Grunwald points out the simple, yet comparatively unstudied, reasons why biofuels are destroying the largest source of living carbon on Earth: The Amazon.

In a word, when land is deforested, a “carbon debt” is created. This is the amount of gas that ethanol would have to replace when burned in order to make up for the carbon that is not longer stored in the vegetation on that land (which has been converted into CO2 via fire).

How long can this take to pay back? In a February 2008 paper in Science magazine, “Land Clearing and the Biofuel Carbon Debt,” scientists find that: “converting rainforests, peatlands, savannas, or grasslands to produce food crop-based biofuels in Brazil, Southeast Asia, and the United States creates a ‘biofuel carbon debt’ by releasing 17 to 420 times more CO2 than the annual greenhouse gas reductions that these biofuels would provide by displacing fossil fuels.”

The basic trend that Grunwald points out is large-scale, global markets at work: Some of the Amazonian deforestation can be traced back to the United States. “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.”

Whew. But really, it’s not too complicated.

Still not convinced? Check any listing of major Brazilian exports and look for the Soybean spike in the last two years.

Should we be worried? Yes. Presently, (again, referencing Grunwald), deforestation accounts for 20% of all current carbon emissions. So even if we improved in many other sectors, we would still be piling on a carbon debt that will take years and years of better transportation or building efficiency or anything else to pay back.

Both Obama and Clinton are trolling for votes in places like Iowa based largely on a platform of homegrown energy. But we must make them see the effects that United States farming and transportation policies are having on the Amazon. The connection is so large-scale that it is tricky to address, and dangerous to ignore.

Contact Madeline Kovacs

at [email protected].