Public Lecture by Werner A. Kurz
Natural Resources Canada, Canadian Forest Service, Victoria BC, V8Z 1M5, e-mail: firstname.lastname@example.org.
Bioenergy derived from forest biomass is considered "carbon neutral" primarily because current accounting rules specify that emissions are accounted when the wood is removed from the forest, not when the carbon is actually emitted to the atmosphere.
Bioenergy is more emissions intensive than fossil fuel alternatives: to produce the same amount of energy more carbon is emitted than from the use of fossil fuels. However, as forests regrow carbon is again removed from the atmosphere. The net atmospheric impact of bioenergy use depends on the rate of carbon uptake in the forest ecosystem from which biomass was removed, as well as the spatial scale and the time horizon over which the assessment is conducted. To assess the mitigation benefits of bioenergy, it is therefore necessary to calculate the net emissions (i.e. the difference between emissions and uptake through forest growth) over time of bioenergy options and compare these to the alternative energy source that is substituted. Bioenergy does not have to be carbon neutral: to contribute to mitigation objectives it merely has to release fewer net emissions than the alternative energy source.
Bioenergy use can contribute towards climate mitigation strategies, but the magnitude and timing of the net benefits need to be quantified to design effective climate change mitigation strategies.