Scrapping older cars for newer eco-friendly models could have a limited effect on reducing greenhouse gas emissions and could drive up costs and material use, a study has found. Researchers say that emissions from light vehicles are responsible for 17 per cent of annual greenhouse gas emissions in countries such as the <a href="https://www.thenationalnews.com/tags/us/" target="_blank">US</a>. To meet net-zero emission targets, some have called for older vehicles to be retired early to accelerate the adoption of emerging technologies that lower emissions. Lifespan caps on vehicles older than ten years could help boost the uptake of <a href="https://www.thenationalnews.com/tags/electric-vehicles/" target="_blank">electric vehicles</a> (EVs), which need to make up 90 per cent of all vehicle sales by 2035 to reach carbon neutrality targets, advocates say. However, a <a href="https://iopscience.iop.org/article/10.1088/2634-4505/ad397e" target="_blank">Toronto University study</a> found that lifespan caps could exacerbate the negative effects of electric vehicle production, including increased usage of critical materials and increased ecotoxicity related to battery production. Millions of spent electric vehicle batteries will need to be recycled by the middle of this decade or could end up in landfills, affecting the environment. The report also says that costs of accelerated electric vehicle production are estimated to be very high and the processes could add to carbon emissions. According to the study, lifespan caps are only effective when implemented alongside complementary strategies, such as electricity grid emission curbs, vehicle fuel consumption improvements, and vehicle production emissions reductions. The researchers used a method known as Fleet Life Cycle Assessment and Material Flow Estimation (Flame) model to make forecasts. This estimates electric vehicle survival curves and battery degradation, and evaluates the effectiveness and cost-efficiency of vehicle lifespan caps in reducing greenhouse gases overall. At least 6.6 million EVs were sold in 2022, almost double the figure from the year before, according to the Paris-based International Energy Agency. Growth was mainly driven by China, Europe and the US. EV sales will soar to about 73 million units in 2040, up from around two million in 2020 according to recent <a href="https://www.thenationalnews.com/business/economy/2023/02/13/electric-vehicles-to-account-for-half-of-global-car-sales-by-2035-amid-net-zero-push/" target="_blank">research by Goldman Sachs</a>. The US-investment firm also forecasts sales of EVs to grow by 32 per cent annually this decade. Many car makers have already promised to phase out models using combustion engines in the coming years, <a href="https://www.thenationalnews.com/lifestyle/motoring/2024/03/19/bentley-bespoke-services-drive-bumper-year-for-luxury-carmaker/" target="_blank">including Bentley</a>, which is hoping to offer an exclusively electric fleet by the 2030s, although this target has been pushed back over changing market conditions. Heather MacLean, a professor in the Faculty of Applied Science and Engineering at the University of Toronto said that lifespan caps may be useful particularly when it comes to reducing GHG emissions, but they can also accelerate the costs. “Our results show that while they may be suitable in some situations, lifespan caps are best positioned as part of a larger integrated strategy for tackling transportation greenhouse gas emissions,” she said. The study was published in <i>Environmental Research: Infrastructure and Sustainability.</i>