ABSTRACT
For many years the potential impact of anthropogenic N2O emissions on the global N2O budget has been a controversial subject of discussion. In the 1980s there was a tendency to attribute the increase in atmospheric N2O concentration primarily to anthropogenic emissions associated with biomass burning, fossil fuel combustion, industrial production of adipic and nitric acids, and the use of N fertilizers. The discovery of an artefact in the procedures used to evaluate the emissions of N2O from fossil fuel combustion (involving also the evaluation of the emission from biomass burning) has drastically changed this situation and the strength of the combustion source has decreased significantly. Linak and co-workers (1990) re-examined the direct role of combustion sources on the observed global rise of N2O in the atmosphere and concluded that direct N2O emissions from conventional fossil fuel combustion are very low. As a consequence, the global N2O flux from this source was reported to be lower by a factor of 50 to 100 than that inferred from previous work and accounted for less than 3 per cent of the entire anthropogenic N2O flux, which was less than the contribution from fertilizers at that time. In this chapter the current knowledge on N2O formation during mobile and stationary combustion, as well as N2O emissions from industrial processes, is reviewed.
