"Many of the problems associated with biofuels are more generally problems with agriculture," Melillo says. Current grain-based biofuel cropping systems are known to cause environmental harm, including soil erosion and depletion, nitrogen fertilizer pollution, and a decline in biodiversity leading to pest management issues. The switch to perennial biofuels crops, such as grasses, shrubs and trees, can mitigate some of these problems and prevent competition with food production. Still, if these crops are sited on marginal lands rather than on cropland, the land could require sizeable inputs of water, nutrients, and energy to become productive.
"If it takes a lot of inputs and if negative environmental consequences persist, then you clearly diminish the benefit you would derive from biofuels production," Melillo says. All the tradeoffs between alternative biofuels strategies need to be carefully considered, the authors write.
One motive for biofuels production is to increase domestic energy security by reducing reliance on imported oil. In addition, introducing biofuels into the nation's energy portfolio promises to reduce the amount of CO2 and greenhouse gases going into the atmosphere by fossil-fuel burning. But this, too, must be carefully thought through by the use of scientific analyses, Melillo says. In some parts of the world, the decision is being made to burn forests to clear land for biofuels crops, wh
|Contact: Diana Kenney|
Marine Biological Laboratory