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Dear Dr. Moore:

I recently heard about a power plant that uses forest debris as fuel. Can burning wood waste reduce our dependence on foreign oil?

Reducing our reliance on foreign oii is one of the advantages of using "biomass"-that's the name for organic matter such as bark. rvood chips and agricultural crops-to produce energy. This is certainly onc of the reasons that governments in North America are seeking to bolstcr their bioenergy industries. But there are environmental benefits as well.

Biomass fuels are renewable and can be burned cleanly. Aside fiom the security risks of sourcing oil from politically unstable parls of the '"vorld. it's also a fossil fuel. Fossil fuels are non-renewable and result in large emissions of carbon dioxide (CO2), thought to be a major cause of global rvarming.

Wood waste can be burned to produce energy in the form of electricity. steam or heat. Some plants make use of forest debris (rvhich is increasingly removed frorn national forests to reduce the risk of lvildfirc) or waste from local sawmills. This approach is also commonly used by forest products companies. rvhieh burn biomass on-sitc to meet their orvn energy needs and sell the surplus. It has the added benefits of diverting rvaste from landfills and lolvering production costs.

When biomass is burned. it also releases CO2, but this is offset by the fact that trees and plants absorb CO2 as they grorv back. The production process also incorporates a variety of pollutitln controls ttl retluce ernissions.

Wood r'vaste can also be converted to ethanol-a fuel commonly distilled from corn and sugar cane-although research is undcrrvay to dctcrrnine if this can be done economically on a large scale. Right norv, any gas-powered engine can run on a mixture of 70%, ethanol and 90o/r, gasoline. Specially designed vehicles can run on a mtxture of 85c/o ethanol and l5a/r, gasoline. Giren that the U.S transp()rtation seet()r gets 97Vc of its energy from oil, this could represcnt a tremendous opportunity to reduce the use of fbssil fuels.

Even though biomass is the second largest source of renewable energy after hydro, there are barriers to creating a stable domestic industry, including a lack of public awateness and support. I can only hope that the heightened risk of sourcing oil in places like the Middle East. combined rvith the envimnmental impacts of fbssil fuels, rvill bring the subject of bioenergy to the mainstream.

Dr. Moore luts hcen u leutltr rtf tlrc enrinttrrtt'rttttl ntovenrcnt.frtr more tlutn -10 vaars. .A to-.ltttrntltr and .fonntr president ol Grrenpeace, Ir lutltls u PhI) itt ttologt' und u BSt in Jbrest biolrtgt. Send que.\lion.\ to putrick@'.rcnsibleenvir( )nrn (! ttl 0l sl,( 0 nt.