Switching to electric vehicles won’t significantly reduce carbon emissions unless countries also transition to cleaner electricity sources, according to a new study from the University of Auckland and Xiamen University in China.
The team used a statistical model to examine the drivers of national CO₂ emissions, analysing data from 26 countries over a 15-year period, finding that higher rates of EV adoption were often associated with increased CO₂ emissions.
It seems that powering EVs using electricity generated from fossil fuels isn’t achieving what we might have hoped.
Miaomiao Tao, a doctoral candidate at the Business School’s Energy Centre said: ‘EV adoption is positively associated with CO₂ emissions. This finding appears counterintuitive; it challenges the conventional belief that EVs contribute to decarbonisation.
‘Our analysis highlights that the environmental benefits of EVs are contingent on the composition of a country’s electricity generation mix.’
Associate Professor Stephen Poletti added that EVs charged using electricity from coal-fired power plants: ‘may indirectly contribute to higher emissions than modern gasoline or diesel vehicles, especially considering the entire lifecycle from production to disposal.’
According to the study, EVs will only begin to make a meaningful dent in global emissions once renewable energy makes up around 48% of electricity generation worldwide. As of 2023, renewables—primarily wind, solar, and hydro—accounted for just over 30% of global electricity.
They point out that New Zealand, where over 80% of electricity comes from renewable sources, is an exception and is well-positioned to benefit from widespread EV use.
Beyond EV adoption, the researchers also looked at the impacts of economic growth, innovation in green technologies, renewable energy use, and population density on emissions. They found that while economic growth tends to increase emissions, innovations in clean technology and higher population density (through more compact urban development) can help reduce them. However, the most impactful factor in lowering emissions was the use of renewable energy.
Poletti added: ‘Electric vehicles are often seen as a silver bullet for climate change, but our results show that’s not the case if the electricity powering them isn’t clean. This research is a reminder that decarbonising transport can’t happen in isolation.’
The full research can be read here.