To ask the Secretary of State for Environment, Food and Rural Affairs, what evidence her Department uses in respect of motorcycle emissions of NOx; how the practice of filtering is reflected in the emissions modelling that her Department uses; and if she will make a statement.
The method for estimating emissions from road transport, including powered two wheelers, is available in the latest National Atmospheric Emissions Inventory’s (NAEI) informative inventory report: https://uk-air.defra.gov.uk/assets/documents/reports/cat09/1904121008_GB_IIR_2019_v2.0.pdf. It uses the internationally recognised COPERT methodology produced by Emisia and if the abatement technology is already incorporated in the emission factor, then it will be reflected in the emissions estimates. Emission factors are presented in the EMEP/EEA Guidebook. The NAEI results for 2017 show that motorcycles and mopeds account for less than 0.5% of road traffic NOx emissions. The NAEI is subject to rigorous international reviews and has a continuous improvement programme to incorporate the latest available evidence.