I came across an article in the Field Crop Advisory Team Alert newsletter from Michigan State University. It’s titled Why Biofuels are Better for the Environment and it presents a good argument for using biofuels.
Here’s an excerpt:
What are the direct net global warming effects of producing ethanol? Based on research conducted at Michigan State University and elsewhere, ethanol is a far superior alternative to petroleum-based fuels with regard to environmental global warming potential (GWP). The figure below shows the net GWP of annual crop (corn) and perennial crop (switchgrass) biofuel cropping systems, relative to the gasoline the harvested biofuels displace. A negative net GWP number means that the system is actually taking greenhouse gases such as carbon dioxide (CO2), methane (CH4) and nitrous oxides (NOx) out of the atmosphere. A positive net GWP number means that gases are being added to the atmosphere and net global warming potential increases.
The data clearly show that the biofuel systems improve GWP relative to using gasoline. How can this be? The mechanism involved is based on photosynthesis.
They also offer this chart: