Converting land to grow biofuel crops as cleaner-burning alternatives to fossil fuels actually results in major new carbon emissions, according to a new study published [Thursday 2/07/08] in the online edition of the journal Science. VOA's Rosanne Skirble reports.
The market for combustible fuel made from plants is booming worldwide. But Joseph Fargione a regional director with the Nature Conservancy and lead author of the new study, says there is a downside to biofuel production.
Fargione says clearing forests, grass and peatlands to make way for biofuel crops like corn and soybeans causes the carbon naturally stored in the soil to escape into the atmosphere.
The study cites prime locations where this is already taking place: The grasslands of the American Midwest, the rainforests and savannahs of Brazil and the peatlands of Southeast Asia. Fargione says the conversion of peatlands to palm oil plantations in Indonesia has caused the greatest carbon losses. "In order to grow palm on those soils, you first have to dig a canal, drain the peat and then plant your palm trees. When you drain that peat it begins to decompose, and vast stores of carbon locked up in that organic soil are released when it is drained."
Fargione says soy production in Brazil ranked second behind corn in terms of this unwelcome soil-carbon release. "You release about 280 tons of carbon to the atmosphere for every hectare you convert, and that is compared to the savings you get when you use biodiesel, which is about .9 tons of CO2 for every year. So it would take you 319 years just to get back to where you started by using biodiesel grown on that land."
New fuel standards in the United States mandate that biofuel production reach 136.3 billion liters by 2022. Fargione says that would require the cultivation of 24.3 million hectares of farmland, or twice the area of Pennsylvania. Yet it would supply only ten percent of the energy needed to meet the nation's transportation demands.
Fargione adds that it's difficult to justify taking land out of food production to produce fuel when global food demand is rising. "You can't ask the world's farmers to feed six billion people and also ask them to produce energy without requiring more land and that land has to come from somewhere, and unfortunately much of that land is coming from our natural ecosystems."
Fargione says biofuels can be produced sustainably, but not from otherwise rich carbon sinks like rainforests, grass and peatlands. He says degraded and abandoned lands no longer useful for agriculture and biomass from organic waste products are the best alternatives. "This includes crop residues, storm or pest-damaged trees. He says one way to reduce the billions of dollars spent on fighting forest fires is to thin trees around people's residences. "These can be used for bio-energy."
Fargione believes that as the worldwide demand for biofuels increases, this new research on the unintended consequence of biofuel production can help policymakers make better land-use decisions.