Frequently Asked Questions
Do electric vehicles produce more CO₂ than petrol or diesel vehicles?
No, they do not.
However, this hasn't always been the case, and in some rare circumstances, EV emissions may be similar to a conventional vehicle. It's also a very complex comparison to make, with many different published studies which have sometimes presented opposing findings, so there are a few things to consider.
How is the electricity generated?
Electric Vehicles are only as clean as the grid which serves them. In areas with coal-intensive electricity generation, the benefits of EVs are smaller, and they can have similar lifetime emissions to the most efficient conventional vehicles.
Thankfully, as countries reduce their emissions to meet their climate targets, grid electricity supply all around the world is getting cleaner as more and more renewable energy supplies come online. An electric vehicle someone bought five years ago produces less CO₂ now than when it was first purchased. In the UK in 2019, Carbon Brief found that the lifetime emissions per kilometre of driving a Nissan Leaf EV were about three times lower than for the average conventional car, even before accounting for the falling carbon intensity of electricity generation during the car's lifetime.
In a petrol or diesel vehicle, there is no opportunity for the emissions to get cleaner over time. What's worse is that by their very design, petrol and diesel cars actively deliver emissions to the places where people are the most, directly affecting air quality and public health.
Carbon Brief's chart compares lifecycle emissions of a conventional vehicle to those of a 2019 Nissan Leaf. Chart by Carbon Brief.
What about manufacturing?
The manufacturing of the batteries for electric vehicles incurs a significant amount of the overall carbon footprint. Many of the associated supply chains are yet to be decarbonised, and critical ingredients such as Lithium, Nickel and Cobalt use extractive industries which are still high-carbon, and the CO² footprint can vary between extraction methods. Overall footprint from manufacturing will vary between different manufacturers based on their choices of supply chains alone.
Within the specific area of Lithium extraction, CO₂ footprint varies hugely between mines and extraction techniques. Image from Vivas Kumar at Benchmark Minerals, data from The CO2 Impact of the 2020s Battery Supply Chain by Alex Grant, David Deak and Robert Pell.
Using low-carbon electricity also hugely affects manufacturing, most likely a constant with all types of vehicle manufacturing, but some EV manufacturers have an advantage over others. Tesla operates some of its battery manufacturing in Nevada, where it plans to eventually run its manufacturing 100% renewably via many renewable energy systems, including solar. Efforts by manufacturers such as these can have a significant impact on lifecycle vehicle emissions for EVs.
Manufacturers can make huge gains in carbon footprints by improving the longevity of the batteries in their vehicles. As battery technology continues to develop, efficiency gains continue to be made. Batteries can also be recycled, further improving the lifecycle emissions of electric vehicles, which is not possible with combustion engines.
Data for the complete manufacturing process of Electric Vehicles has been hard to come by, which has led to such differences in report data for lifecycle emissions. For example, the IVL 2017 Study which concluded that battery manufacturing emissions are likely between 150 and 200 kg CO₂-equivalent per kWh of battery capacity was updated in late 2019 with a substantial revision. Researchers now estimate that "battery manufacturing emissions are actually between 61 and 106 kg CO₂-equivalent per kWh, with an upper bound of 146 kg".
Carbon Brief's comparison shows the differences in studies of battery lifecycle emissions, both how they vary and how they've changed over time. Chart by Carbon Brief.
Beware of misinformation or outdated reports
Energy generation and electric vehicle technology are rapidly changing and improving all the time. Additionally, the comparison between electric and petrol or diesel engines is complex, and there are vested interests from fossil fuel companies to see electric vehicles fail. It's relatively easy to claim that electric cars are worse for climate change. All you need to do to present the case that electric cars produce a lot of CO₂ is to use outdated EV battery production data with high carbon, fossil fuel electricity generation. Then compare it to manufacture-quoted lab data for fuel efficiency of small size petrol or diesel vehicles (yes, the same data that got VW in a multi-billion dollar lawsuit) and you're probably nearly there.
Article thumbnail photo by Anne Nygård on Unsplash.
Article last updated on November 8th 2022.