Global View

Since humans learned to control fire, biofuels have been an important energy resource. In general, biofuels are organic materials derived from recently living matter, in contrast to fossil fuels. In many undeveloped countries, wood and other biomass continues to provide primary energy for basic necessities. Developed countries are beginning to grow crops specifically intended to provide biofuels such as ethanol from sugar cane and corn (maize.)

If vegetation to supply biofuels is grown sustainably, the use of these fuels contributes little to global warming. In a matter of years, the vegetation absorbs carbon dioxide as it grows, releases carbon dioxide into the atmosphere when burned, and a new generation of vegetation reabsorbs the carbon dioxide to complete the cycle.

Unfortunately, many of the crops currently touted for biofuels are not grown sustainably. Modern agricultural practices for growing corn, for example, are heavily dependent on fossil fuels for equipment, fertilizer, ethanol fermentation, and transportation. Whether ethanol from corn reduces net carbon dioxide emissions or not is a controversial question. Production of biofuels from cellulose obtained from less energy intensive crops has been under development for many years but has not yet achieved commercialization.

Municipal organic waste treatment facilities produce methane in the decay process which can be used as fuel. Since methane is a potent greenhouse gas, allowing it to escape into the atmosphere exacerbates global warming, so increasingly these emissions are captured, cleaned and used as biofuel.

United States

The US provides hefty subsidies for ethanol made from crops, mostly corn. In response, the price of corn has increased substantially, raising fears of impacts to the global food supply. Ethanol is blended with gasoline and the mixture is used as automotive fuel. However, the energy required to grow and transport corn, manufacture ethanol, and transport it to market raises concerns that the use of this fuel does little, if anything, to reduce net emissions of carbon dioxide.

California

California is weighing the benefits of the use of ethanol as an implementation strategy to reduce greenhouse gas emissions. Capture and use of methane from municipal landfills and sewage treatment facilities is now common in the state. Wood and crop waste is frequently burned as fuel to generate electricity.

Animal waste, especially from California’s large dairy operations, creates air and water quality problems. Processing manure in anaerobic digesters to produce methane is now in the developmental stages.