Electric vehicles (EVs) are often touted as a solution to climate change, but a new study reveals that their environmental benefits are negligible unless powered by clean energy. Researchers from the University of Auckland and Xiamen University found that higher EV adoption has surprisingly been linked to increased CO₂ emissions in many countries.
A new international study published in the journal Energy has compellingly challenged the conventional wisdom that electric vehicles (EVs) are inherently eco-friendly. Conducted by researchers from the University of Auckland and Xiamen University in China, the study reveals that the adoption of EVs does not lead to a reduction in carbon emissions unless the electricity used to power them is sourced from renewable energy.
Stephen Poletti, an associate professor at the University of Auckland, and Miaomiao (Simon) Tao, a doctoral candidate at the University of Auckland’s Business School Energy Centre, spearheaded the research.
Examining data from 26 countries over a period of 15 years, the researchers used robust statistical methods to scrutinize the contributing factors to national carbon dioxide (CO₂) emissions.
Their findings are both surprising and significant: in numerous countries, increased EV uptake has been paradoxically linked with higher CO₂ emissions.
“On the contrary, EV adoption is positively associated with CO₂ emissions,” Tao said in a news release.
This insight disrupts the prevailing belief that EVs automatically contribute to decarbonization. The research underscores that the true environmental impact of EVs is contingent on the nature of a country’s electricity generation.
In many nations, EVs are still largely powered by electricity derived from fossil fuels, such as coal or oil. For example, charging EVs with electricity from coal-fired power plants can sometimes result in higher emissions over the vehicle’s lifecycle compared to modern gasoline or diesel vehicles, according to Poletti.
The findings suggest that electric vehicle adoption will contribute to reduction of CO₂ emissions only when renewable electricity makes up about 48% of the global electric supply.
However, in 2023, renewable energy — including wind, solar and hydro — made up just over 30% of the world’s electricity supply, indicating a significant gap yet to be bridged, according to Poletti.
The research draws particular attention to New Zealand, where over 80% of electricity generation comes from renewable sources, placing the country in a strong position to benefit from EV adoption.
“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,” added Poletti.
In addition to analyzing the impact of EVs, the researchers also considered other factors influencing emissions, such as economic growth, green technology innovation, renewable energy consumption and population density.
They observed that while economic growth generally leads to increased emissions, advancements in environmentally friendly technology and higher population density in the form of compact cities can contribute to lowering them. Significantly, renewable energy use had the most profound effect on reducing emissions.
“This research is a reminder that decarbonizing transport can’t happen in isolation,” Poletti added.
In essence, for EVs to truly contribute to global decarbonization efforts, they must be integrated within a broader context of sustainable energy consumption and infrastructure development.
Source: University of Auckland