Holly Gibbs, a postdoctoral researcher at Stanford University's Woods Institute for the Environment, said policies favoring biofuel crop production might actually contribute to, not slow, the process of climate change.
"If we run our cars on biofuels produced in the tropics, chances will be good that we are effectively burning rainforests in our gas tanks," she said. "When trees are cut down to make room for new farmland, they are usually burned, sending their stored carbon to the atmosphere as carbon dioxide. That creates what's called a carbon debt," Gibbs said. "This is because the carbon lost from deforestation is much greater than the carbon saved from using the current-generation biofuels."
She said such an environmental disaster could be imminent "without more thoughtful energy policies that consider potential ripple effects on tropical forests."
Gibbs analyzed satellite images collected between 1980 and 2000 in the first such detailed characterization of the pathways of agricultural expansion across the entire tropical region. Gibbs said she hopes her findings will contribute to prudent decisions about future biofuel policies and subsidies.
The research was presented last weekend in Chicago during the annual meeting of the American Association for the Advancement of Science.