## 2 Method for Comparing ICEVs and BEVs--Life Cycle Assessments (LCAs)  
Understanding the lifecycle emissions of different vehicle types is essential for assessing their environmental impact and guiding consumer policy and choice. Life Cycle Assessments (LCAs) provide a comprehensive assessment covering raw material extraction, vehicle manufacturing, energy production, and end-of-life processes, including recycling and reuse. It provides a comprehensive comparison of the environmental impacts of BEVs and ICEVs and identifies critical areas for environmental improvement throughout the vehicle life cycle. This comprehensive approach uses metric tonnes of CO2e as the standardized unit, considering several greenhouse gases and their global warming potential [24]. The BEV production phase is around 40% more intensive in terms of emissions than that of hybrid and ICE vehicles [25]. This disparity is mainly due to the extraction and refining of raw materials such as lithium, cobalt, and nickel, which are essential for battery production, and the energy-intensive manufacturing processes involved [25]. These factors significantly contribute to the higher production emissions associated with BEVs [26]. However, by 2050, these BEV production emissions are expected to be only marginally higher than those of conventional vehicles. Batteries are responsible for around 60% of the GHG emissions from the production of electric vehicles [14]. This paper presents a Life Cycle Assessment (LCA) methodology, along with the framework, boundaries, limitations, assumptions, and rationale behind it. It provides key findings from each stage of the life cycle phase, highlights the method's sensitivity to assumptions, and concludes with recommendations. The study examined a range of vehicle configurations, including traditional internal combustion engines and electrified powertrains, assessing their environmental performance under current and future market scenarios. The study also assessed the environmental footprint of BEVs and ICE vehicles over their entire life cycle, from raw material extraction to end-of-life processes. It identified the critical factors influencing emissions and the conditions under which BEVs become environmentally advantageous. The key objectives included the following:  
* Comparing the total life cycle emissions for BEVs and ICE vehicles;
* Evaluating the impact of energy sources and battery production on GHG emissions;
* Assessing the role of recycling and maintenance in emission reductions. Figure 4: Carbon intensity over the life cycle of the electricity grid in different countries, 1990–2023 (adapted from [23]). The scope focused on light-duty passenger vehicles of various sizes (small, medium, and large) and using different energy sources (petrol, diesel, and electricity), considering regional variations in electricity production and battery manufacturing. This research followed the ISO 14040 standard's four-step process, as shown in Figure 5.  
Step 1. Goal and Scope Definition. * Establish clear objectives for comparing BEVs and ICE vehicles. * Define boundaries to include vehicle production, energy production, use phase, maintenance, and end-of-life processes. * Document assumptions, such as energy grid compositions and vehicle lifespans, ensuring that they are transparent and aligned with the study's objectives. Step 2. Life Cycle Inventory (LCI). Compile raw material, energy input, emission, and by-product data across all phases. * Production Phase: includes emissions from vehicle manufacturing (excluding and including battery production) and battery production (varying by country and battery chemistry). * Use Phase: combines Well-to-Wheel (WTW) emissions including WTT (Well-to-Tank; emissions from fuel extraction, refining, and transportation) and TTW (Tank-to-Wheel; combustion or electricity use during operation). * End-of-Life Phase: covers emissions from recycling, disposal, and remanufacturing. Step 3. Impact Assessment.