Full benefit of EV transition won’t be felt until mid-century

Imposing a ban on the sale of new petrol and diesel cars, as some countries plan to do in the coming decades (the UK has brought forward its planned phase-out date from 2035 to 2030), would greatly reduce carbon emissions and improve air quality. In Sweden, home to Chalmers University, the government has proposed a mandatory phasing in of electric cars with an outright ban on new fossil fuel cars from 2030.

According to this study, which looked at emissions from the entire life cycle of a vehicle, this proposal could cause emissions from Swedish passenger vehicles to approach zero, but not until 2045.

“The lifespan of the cars currently on the roads and those which would be sold before the introduction of such a restriction mean that it would take some time – around 20 years – before the full effect becomes visible,” said Dr Johannes Morfeldt, lead author of the study.

To have the desired effect, a ban would either need to be introduced by the year 2025 or – if the ban is not introduced until 2030 – the use of biofuels in petrol and diesel cars would need to increase significantly before then in accordance with revised Swedish “reduction obligations”. Combining these two measures could allow Sweden to achieve zero carbon emissions from passenger vehicles.

“The results from our study show that rapid electrification of the Swedish car fleet would reduce life cycle emissions from the 14 million tonnes of carbon dioxide in 2020 to between three and five million tonnes by the year 2045,” Morfeldt explained. “The end result in 2045 will depend mainly on the extent to which possible emission reductions in the manufacturing industry are realised.”

This transition will drive a huge increase in demand for batteries, which produce high levels of greenhouse gas emissions during manufacturing. The researchers found, however, that average emissions from battery manufacturing could feasibly be cut by two-thirds per kWh of battery capacity by 2045.

From a climate perspective, the place that emissions are produced does not matter, and there is a risk that national decision makers, such as the Swedish government, could take action which significantly cuts their national emissions but leads to (smaller) increased emissions elsewhere (“carbon leakage”). In this case, the increase in emissions would come from increase demand for EV batteries. The researchers argue that there is a case to regulate emissions from a life cycle perspective, accounting for both vehicle and battery production.

“Within the EU, for example, there is a discussion about setting a common standard for the manufacture of batteries and vehicles – in a similar way as there is a standard that regulates what may be emitted from exhausts,” Morfeldt said.

Although the results of this particular study is based on conditions in Sweden – and the 2045 figure was selected as this is Sweden’s deadline for reaching net-zero greenhouse gas emissions – the method can be used to obtain corresponding figures for other countries, using data on their car fleets and energy systems.