Question to the Department for Transport:

To ask Her Majesty's Government what assessment they have made of the case for a standardised formula for assessing vehicular carbon footprint to ensure a reliable comparative assessment system that has public confidence.

We have not made an assessment of the case for a standardised formula for assessing vehicle carbon footprint.

However, the Government has carried out a relative assessment, in terms of air pollutants and greenhouse gas emissions, of different fuel and powertrain options based on outputs from the Transport Energy Model, which was published alongside the Road to Zero strategy in 2018. The modelling makes clear that, even with the current electricity grid emissions, battery electric vehicles are estimated to have greenhouse gas emissions 66% lower than a petrol car and 60% lower than a diesel car. Between now and 2050 we project that grid emissions will fall by around 90%, with total emissions from electric vehicles falling in parallel.

As well as considering the greenhouse gas emissions from energy production, we have also considered the emissions from battery production. As battery production is an energy intensive process we would also expect these emissions to fall over the period to 2050. We are clear that battery electric vehicles have substantially lower greenhouse gas emissions than conventional vehicles even when taking into account the electricity source and electricity used for battery production.