A group of Italian researchers analyzed the entire life cycle of e-vehicles and vehicles with internal combustion vehicles to determine the extent, to which their environmental impact is different. The results of the study showed that e-vehicles really allow for significant decrease of greenhouse gases emissions across their entire life cycle. However, this benefit for the climate is achieved due to high raw materials load: batteries production requires big volumes of rare metals, and their mining and processing are connected with serious environmental and social risks.
The Intended Nationally Determined Contributions formed the legal framework to incentivize national governments to gradually reduce the share of vehicles with internal combustion engines (ICE). In certain countries and associations these measures are especially strict. Thus, in 2023, the European Union adopted the Regulation about 100% reduction of CO₂ emissions from cars by 2035 vs the 2021 level. This actually means termination of new ICE cars sales (including hybrids) by 2035. At the same time the implications of massive switching to EVs by the EU countries for environment and natural resources have not been fully studied yet.
The scientists from Rome University became the pioneers of comprehensive approach to such studies. They compared two versions of one and the same car (Peugeot 308) – one with diesel-fueled engine, and the second one with electric motor unit.
The study was based on the Life Cycle Assessment (LCA)method allowing for defining the cumulative environmental footprint of a product across its entire life cycle: from extracting raw materials and manufacturing to operating and disposal. Specifically, the study covered three stages: manufacturing, operating and life cycle termination, and demonstrated illustrative and comparable results.
At the manufacturing stage, the e-vehicle turned out to be much more resource-intensive and generating more emissions: the carbon footprint made 20.4 tons of CO₂ versus 9.6 tons for the diesel-fueled version, and the mineral resources consumption rate for EVs turned out to be 7–10 times higher. The main load is associated with manufacturing batteries composed of lithium, nickel, cobalt, lead and copper. However, at the operations stage, the e-vehicle demonstrated its advantages: with the run of 200,000 km it emits 24 tons of CO₂, while as diesel-fueled car — 52 tons. When the run increases up to 540,000 km, the difference becomes even more noticeable — 37 tons vs 131. This is underpinned by higher energy efficiency of electric motor and gradual decrease of carbon share in electricity generation. At the final stage, re-cycling played an important role: when using hydrometallurgical process, the significant share of the initial loss is compensated — for copper alone it means minus 2.7 tons of the equivalent.
The researchers also analyzed the model sensitivity to understand what specific parameters have the biggest impact on the environmental characteristics of cars. Such analysis helps to understand the extent of changes of the results when varying certain factors. Three parameters were identified as having the biggest impact on environmental performance: the energy density of the battery (the higher it is, the lower is the weight and the feedstock footprint), the life cycle of the battery (the number of charging/discharging cycles) and the fuel consumption rate of the diesel-fueled car. For example, if the diesel consumption rate grows from 5 up to 8–10 liters per 100 km, the climatic advantages of such vehicle are lost completely.
The researchers emphasize that the existing methods of environmental impact evaluation do not take into account the extent of shortage and the strategic value of the materials. To mitigate this, they propose to introduce two additional indicators: the extraction/reserves index reflecting the resources depletion rate, and Gini index reflecting the degree of the extraction concentration in certain countries.
In general, the study confirms the climatic advantages of e-vehicles vs the cars with internal combustion engines. However, without development of batteries re-cycling technologies, diversification of feedstock supplies, and more accurate instruments for assessing the dependency on resources, the massive transition to e-vehicles may generate new forms of instability and environmental pressure.
