Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, with reference to transport refrigeration units emissions, (a) how the Government is measuring levels of those emissions, (b) how often data on those emissions is published and (c) for how long that data been collected.

Tailpipe emissions from vehicles which power transport refrigeration units are recorded as road traffic emissions in the National Atmospheric Emissions Inventory. The data for road transport emissions is published annually and has been reported since 1990 onwards. The Government does not estimate emissions from transport refrigeration unit auxiliary engines as the available data are limited.

Defra has commissioned research and is working with industry and sector experts to improve the evidence base on emissions from non-road mobile machinery emissions, including transport refrigeration units. As set out in the Clean Air Strategy, the Government is considering the options to reduce emissions from non-road mobile machinery.