Greenhouse gas emission factors for coal (Adams, 06-2008)

Accurate emission inventories of greenhouse gases are becoming increasingly important as countries make efforts to comply with the Kyoto Protocol and as emissions trading develops. Emission factors are widely used to calculate emissions by multiplying the amount of activity by the relevant emission factor. The IPCC provides emission factors for the coal fuel cycle and guidance on their use. The US EPA has published many emission factors. Organisations such as ISO andWRI/WBCSD provide guidance on the use of emission factors. CEMS are the main alternative to emission factors for compiling inventories. Both methods are acceptable for CO2 from coal combustion. There is more uncertainty about emissions of CH4 and N2O. There are a number of sources of uncertainty; much of it can be quantified. Emission factors would be improved by greater acknowledgement of the inherent uncertainty in the numbers.