## 2 Ecological Impacts
This growth underscores the critical role of aluminum in enabling the development of lighter and more efficient vehicle designs, solidifying its position as a key material in advancing sustainability within the transportation industry. To align with net-zero objectives, stakeholders, including manufacturers, consumers, and policymakers, must enhance more sustainable aluminum processing technologies and improve aluminum scrap collection, sorting, and recycling. These coordinated efforts are essential for reducing waste, lowering emissions across the supply chain, and achieving global climate goals [11]. Among more sustainable aluminum processing technologies, AM emerges as a promising solution. AM is a transformative approach to producing complex mechanical and structural components, positioning itself as a major catalyst in the Fourth Industrial Revolution, also known as digital industrial transformation. AM significantly reduces material waste through its \"near-net-shape\" approach, producing components with complex geometries while using only the necessary material. Furthermore, the design optimization enabled by AM allows for the creation of lighter and more efficient components, contributing to energy savings in industries. It further facilitates the creation of multi-part assemblies, functionally graded materials, and meta-materials, capabilities often challenging or unattainable through conventional manufacturing. Consequently, AM is not only redefining conventional manufacturing paradigms but also advancing sustainable development by minimizing resource usage and promoting localized production models that help lower the carbon footprint associated with extended supply chains. Although the material efficiency and supply chain shortening that characterize AM bear the potential to advance the sustainability of these processes over traditional manufacturing methods, much of additive technology is energy intensive and often has a higher carbon footprint per kilogram of final product than traditional manufacturing techniques [8]. The PBF-LB/M additive technology is particularly critical from a sustainability perspective due to its environmental impact, which is contributed to by the energy-intensive production of metal powders, the significant consumption of inert gas during processing, and the challenges in recycling unused powder. To evaluate and mitigate these impacts, Product Carbon Footprint calculations, following the ISO 14067 standard [29], are a valid tool to quantify the CO2 emissions (expressed in kg CO2 equivalent) linked to the production of each kilogram of metal powder. Additionally, ISO 14040 [30], which provides guidelines for LCA, can be useful to assess the total environmental impact of products throughout their entire life cycle, from raw material extraction to disposal or recycling. LCA is a comprehensive framework for evaluating the environmental impacts of a product system, such as energy consumption and CO2 emissions, across various phases of its life cycle. It systematically analyzes inputs and outputs throughout the product lifespan and interprets the results to support sustainable decision-making. A PBFed product life cycle typically consists of five phases: material production, which involves raw material extraction and processing; manufacturing, which focuses on the fabrication of parts or components; transport, which includes the distribution of parts or products to assembly sites or end-users; use, which covers operational impacts during the product usage phase; and disposal, which entails end-of-life management, including recycling or landfill. LCA can be adapted to different system boundaries. Cradle-to-grave assessments include all phases from raw material extraction to end-of-life disposal, while cradle-to-gate studies focus on material production and manufacturing, and gate-to-gate analyzes examine only the manufacturing process. Figure 3 illustrates the system boundaries and phases of the product life cycle specific to PBF-LB/M.