The October 2007 issue of National Geographic contains a detailed discussion of the pros and cons of various bio-fuels. Among thefindings: Corn-based ethanol at best breaks even on CO2 emissions.  Sugar based ethanol, used in Brazil, is far more efficient. Biodiesel, made from soybeans is more efficient than corn-based ethanol.

But Brazil is clear-cutting rainforest at a frightening pace to  plant sugar cane for ethanol and soybeans for bio-diesel. Is Brazil part of the solution, or part of the problem?

Extensive use of biofuels will also have the effect of removing land from food production, thereby driving up food prices. A better option is “cellulosic ethanol”, ethanol derived by using enzymes to break down biomass as switch grass, corn stalks, etc. SunOpta, a Canadian organic foods company, is already operating plants that produce cellulosic ethanol.

Another possible future development is the use of algae to convert CO2 emissions from coal fired power plants to biodiesel.

David Sattinger will conduct a discussion group on Global Warming: Changing Course, based on a Discussion Guide published by the Northwest Earth Institute. One of our activities will be to calculate our individual carbon footprint, i.e. a measure of how much CO2 our activities contribute to the atmosphere.

For tips on how to reduce your CO2 emissions, see The Green Guide by National Geographic, or the U.S. Climate Technology Cooperation Gateway which is somewhat more technical.

Some other links you may find useful are energystar, a government web site with information on energy efficiency of household appliances, and Our Garden Catalina, a family run organic foods farm in Catalina, Arizona.