The average new car is 12.6% more efficient than its predecessor, according to the SMMT. Yet in September 2018, average CO2 emissions of the new cars registered in the UK reached a six-year high of 128.3g/km.

The rise in CO2 emissions is the latest by-product of the Dieselgate scandal, and the biggest jump yet in an upward trend since CO2 emissions reached a low of 119.2g/km in August 2016. 

Electrified cars are not selling at the same rate as the diesel decline, so buyers are returning to petrol, and CO2 emissions are going up. CO2 emissions will increase further in the short term with the more real-world-representative WLTP economy tests.

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All this is bad news for the Government, as it has a legal obligation to improve air quality and reduce CO2 emissions.

This is a government that has also recently started a consultation for how the UK should regulate CO2 emissions for cars in the event of a no-deal Brexit outcome.

The government’s position on the consultation, which closes on 28 November, proposes that the UK is “at least as ambitious as the regulations established in the EU” and will seek to closely align to the EU-wide target of 95g/km for an industry fleet average to avoid that particular part of a car maker’s business plan being ripped up.

Interestingly, there is a nod to the fact that Britain tends to make heavier cars than the rest of the EU (our main domestic car maker being Jaguar Land Rover, not, say, Fiat), which could be proportionally reflected in the figures. There’s also the maintaining of super-credits, which reward car makers who make zero-emission vehicles.