Metals are vital to the operations of contemporary society in the form of transportation, construction, machinery, and infrastructure (Gerst and Graedel, 2008). The “”major metals,”” in particular, have a long history of human use and offer civilization the goods and services necessary to satisfy basic human needs. However, a number of environmental issues, including climate change, biodiversity loss, and particulate matter health consequences, are becoming more severe as a result of the extraction and processing of these metals (IRP, 2020). This circumstance raises the important question of how to satisfy the demand for metal goods and services from a growing global population without going over the planet’s carrying capacity (Jaramillo and Destouni, 2015).
- Selection criteria
Two databases, Web of Science and Scopus, were used to compile general papers on long-term scenario analysis for main metal demand and supply and related environmental implications. First, we extracted all of the articles from 1995 to May 2020.
(1) Instead of focusing only on historical developments, the study analyses the position after 2025.
(2) Rather than focusing on a small number of limited products, the study examines a broad sector that will influence future metal flows and stocks.
These approaches are employed in a dynamic examination of material flow (Müller et al., 2014). Concurrently, in order to present a complete picture of how scientists anticipate key metal demand and supply to vary over time, we built a dataset combining expected world demand and supply statistics culled from several pertinent articles.
Critical Earth systems, such as the processes that control climate and ecosystems, are hampered by the extraction and processing of important metals (IRP, 2019). It is crucial to evaluate how long-term scenarios for important metals will impact the global environment while thinking about how to adopt sustainable metal demand, supply, and strategy. Therefore, we looked into how well each metal study had covered various environmental impacts. We identified many sorts of indicators for evaluating environmental impacts, including status indicators and indicators of pressure (such as greenhouse gas emissions) (e.g., atmospheric CO2 concentration). Additionally, depending on how fully pressure indicators are integrated, most life cycle evaluations use various representation techniques, such as midpoints and endpoints (Guinee, 2002).
Material efficiency strategies
Terms like material efficiency, circular economy, and 3R are also gaining popularity, as are strategies for encouraging sustainable metal cycles. Although each of these methods has a few subtle differences, they all share a lot of the same core ideas (IRP, 2020). As a result, based on the literature, we defined the following cross-cutting strategies that span the whole life cycle (IRP, 2020),
- Product design phase: Light-weighting and substitution.
- Manufacturing phase: Fabrication yield improvements.
- Use phase: More intensive use and lifetime extension.
- End-of-life phase: Reuse, re-manufacturing, and recycling.
Results and discussion
A sharp rise in the number of articles published on major metals’ long-term possibilities, particularly in the past five years. Iron and steel-related publications predominated, followed by those on copper, aluminum, zinc, nickel, and lead. The remaining 27% of the research, including China (19%) and the U.S. (27%) focused on national and regional levels. Of the 70 studies chosen, 73% examined future scenarios at a global level (3 percent ). The selected studies covered a range of temporal scales, from 2030 to 2400, with 24% of them giving evaluations through 2100 and 51% through 2050.
According to the median of the data points, aluminum would experience the highest growth rate in 2050 compared to 2010 (215%), followed by copper (140%), nickel (140%), iron (86%), zinc (81%) and lead (46 percent ). We can also affirm that demand for all main metals, with the exception of lead, is anticipated to rise steadily by the end of the century, with aluminum experiencing the highest growth rates (470%), followed by copper (330%), zinc (130%), and iron (12%). (100 percent ). The demand for nickel in this situation by 2100 could not be predicted by previous research. These findings suggest that, depending on the type of metal, the demand for the key metals will likely increase by 2 to 6 times during the 21st century. Additionally, as the year’s data points 2100 are limited, especially for zinc, lead, and nickel, the long-term outcomes of these metals are unclear.