Finding substitutes for fossil fuels is a central strategy for most nations trying to slow global warming. Yet in a stunning setback for the burgeoning biofuels industry, a pair of studies released Thursday suggest that almost all forms of ethanol and biodiesel being made today give off more greenhouse gas emissions than do conventional fossil fuels.
Published in Science, a peer-reviewed journal, the studies are a fresh cause for worry for today’s biofuel makers. Though still in its infancy, the industry faces growing criticism for the damage biofuel production does to food prices, water tables, and the environment. The new studies suggest practically all biofuels produce no net short-term reduction in green house gas (GHG) emissions.
Here’s why. The studies differ from past efforts by, for the first time, taking into account the vast swaths of virgin land — often in tropical climes, including rain forest — being put under the plow to grow palm, canola and corn to produce road fuel. By razing these natural ecosystems, farmers release GHGs not just when the land is cleared cut and burned but they also prevent CO2 from being absorbed by the mature plants in the future. When a stand of trees or grasses is felled, they give off CO2 when they rot, and they no longer act as as a “carbon sink” soaking up CO2 in future years.
In one example, the clearing of grass lands led to the release of a staggering 93 times the volume of greenhouse gases that would be saved by producing fuel from crops grown on that land in a year. In other words, it will take 93 years to offset the GHGs freed to start farming the plot. Given that Europe has recently begun to take into account such such second- and third-order sources of GHGs in its biofuel policies, the developments could lead to far fewer biofuels being qualified for subsidies and is likely to steer the industry away from today’s corn, palm, and canola crops toward less familiar, less mature options such as cellulosic ethanol, oil from waste, and algal oils.
For a deeper dive, check out Elizabeth Rosenthal’s thorough treatment of the issue in the NYT.
BusinessWeek correspondents John Carey and Mark Scott, cover the green scene, keeping on top of the business aspects of energy, the environment and climate change, as well as the technologies, policies, markets and people that are shaping how the earth's resources will be used in the century ahead.