A historic but largely overlooked shift took place in 2009: that year, for the first time in history, the majority of people on the planet lived in cities1 — and urbanization has shown no signs of slowing down since. Today, 55% of the world’s population resides in urban areas, which are expected to swell by another 2.5 billion people by 20502. The number of megacities, urban areas with over 10 million residents, is also expected to grow from 37 to 48 over the next 10 years3.
This rapid growth is placing enormous pressure on infrastructure, as transportation systems, housing, energy grids, and digital networks must all scale to meet the rising demands of modernization. Urban development has enormous potential to improve the quality of life for billions of people; with shared infrastructure and services, cities can provide better access to education, healthcare, jobs, and housing while reducing resource use and per-capita emissions. However, dense urban populations require infrastructure that is extensive, resilient, and able to scale rapidly and sustainably — and that depends on a massive and growing supply of durable raw materials.
Metals, in particular, play a central role in developing the infrastructure of the future. From reinforced high-rises to efficient transportation and reliable, clean energy, the physical structure of urban life depends on a steady, resilient supply of the right metals. Understanding which metals cities rely on and how those needs are evolving is key to meeting the demands of a rapidly urbanizing world.
The vertical city: urban construction at scale
”By 2060, the world is projected to double its building stock, adding another 230 billion square meters of floor space — the equivalent of all the buildings that exist today.
From São Paulo to Shenzhen, the global skyline is changing quickly. By 2060, the world is projected to double its building stock, adding another 230 billion square meters of floor space — the equivalent of all the buildings that exist today4. Much of this growth will take the form of high-rise construction in rapidly urbanizing regions.
Skyscrapers now serve as multi-use infrastructure, housing residents alongside businesses, schools, hospitals, and public services, while preserving space for parks and transit corridors. Unlike single-family homes or low-rise buildings, high rises require structural strength, fire resistance, and durability that cannot be obtained from wood, brick, or other local materials. Large-scale construction requires a wide range of materials, including cement, concrete, glass, plastics, and a variety of metals. Among the metals used, copper, nickel, and zinc are especially important, thanks to unique properties that support strength, efficiency, and durability.
Copper
Copper’s exceptional electrical and thermal conductivity, paired with high corrosion resistance, make it central to the safe and efficient operation of today’s buildings and indispensable in the construction of high rises and the broader systems that keep them running. Copper wiring supports everything from lighting and communications systems to building automation, fire alarms, and emergency power. Its conductivity also enables energy-efficient heat exchange in air conditioning and hot water systems. As more buildings incorporate electric vehicle charging stations, rooftop solar, and smart energy management systems copper’s role becomes even more critical.
As of 2024, a quarter of all copper produced globally was used in the construction sector, a number that is expected to rise to 28% by 2050, with annual consumption of copper for construction increasing by 86%5.
Nickel
Nickel plays a key role in urban construction thanks to its use in stainless steel, an alloy prized for its strength, corrosion resistance, and long service life. Currently, around two-thirds of global nickel is used to produce stainless steel6, which is used extensively in plumbing systems, water and wastewater treatment infrastructure, public kitchens, elevators, HVAC systems, and cladding.
Appian estimates that construction currently accounts for about 15% of global stainless-steel demand7. Overall consumption of stainless steel is expected to grow 43% by 2050 and the amount of nickel needed for stainless steel used in production is projected to rise from 341 thousand tonnes per year in 2025 to 448 thousand tonnes in 20508.
Zinc
Urbanization and industrialization are the dominant driving forces of global zinc consumption, with more than half of zinc end demand being in construction. Galvanized steel is the main source of consumption of zinc in construction, with galvanization being the process of applying a protective zinc coating to steel or iron to prevent rust and corrosion. When exposed to moisture and air, untreated steel can corrode rapidly, compromising the integrity of structures over time. Galvanized steel, on the other hand, resists corrosion for decades.
In urban construction, this makes galvanized steel ideal for roofs, structural supports, balconies, cladding, railings, fasteners, and exposed steel components. This is particularly important in locations where heat and humidity accelerate corrosion, a common challenge in many of the world’s fastest-growing cities. In these environments, galvanized steel extends the lifespan of critical infrastructure and reduces long-term maintenance costs, making it a practical and resilient choice for urban development.
As cities grow, the demand for galvanized steel is rising. This, in turn, is driving strong growth in the zinc market, with the construction sector expected to consume three million tonnes more zinc per year in 2050 than today9.
Moving millions: the material demands of 21st-century transit
”As more nations adopt decarbonization and emissions targets, demand for electrified transport infrastructure is expected to rise sharply, accelerating the need for key industrial metals such as copper, nickel, and zinc.
As urban populations grow, the ability to move people and goods swiftly and sustainably becomes increasingly important. Subways, light rail, bridges, highways, airports, ports, and electric vehicle infrastructure connect workers to jobs, goods to markets, and cities to one another. Mass transit systems are especially vital in dense urban areas, where they help reduce energy use and per-capita emissions. To date, the most ambitious global effort to expand transport infrastructure is China’s Belt and Road Initiative (BRI). A multi-trillion-dollar project with a target completion date of 2049, BRI is rapidly constructing a web of railways, ports, energy pipelines, and highways across Asia, Africa, and parts of Europe10.
At the same time, countries around the world are investing heavily in electric vehicles, charging infrastructure, high-speed rail, and transit systems powered by renewable energy. As more nations adopt decarbonization and emissions targets, demand for electrified transport infrastructure is expected to rise sharply, accelerating the need for key industrial metals such as copper, nickel, and zinc.
Copper
Copper’s unmatched electrical conductivity plays an important role in electric vehicles (EVs), which rely on the metal for motors, inverters, wiring, and battery connections; on average, an EV uses nearly three times more copper than its internal combustion equivalent11.
But copper’s role extends well beyond the vehicles themselves; it is also critical in building out the charging infrastructure, power distribution systems, and grid connections that electrified transport requires. As more countries invest in high-speed rail, public transit electrification, and EV adoption, copper demand from the transportation sector is expected to grow at an annual rate of 4.0% between 2021 to 2050, climbing from roughly 3.4 million tonnes to over 11 million tonnes per year.
Nickel
Nickel plays two essential roles in transportation. As a key component of stainless steel, it enhances the strength and corrosion resistance of vehicles, tunnels, bridges, and rail systems. With transportation making up 13.4% of global stainless steel demand12, nickel plays a substantial role in meeting the sector’s growing need for durable, high-performance materials.
Nickel is also a key component of lithium-ion batteries, which increase the energy density and extend the driving range of electric vehicles. As global transportation shifts toward electrification and low-emission infrastructure, demand for nickel specifically for use in batteries is expected to grow at an annual rate of 5.8% until 2050, with demand doubling by 203013.
Zinc
Zinc plays an essential role in the transport sector, again primarily through its use in galvanizing steel. By forming a durable barrier against moisture, salt, and temperature extremes, it protects bridges, rail networks, and vehicle bodies from corrosion. In urban environments with heavy traffic and fluctuating climates, this protection is critical to maintaining the integrity and longevity of transportation infrastructure.
The hidden network — powering the cities of the future
”Aging infrastructure, surging digital demand, and the shift to electric transportation are pushing current systems to their limits. With the rapid growth of AI usage and data centers, grids will need to double or even triple in capacity and resilience.
Behind every light switch, subway train, and data center lies a vast and mostly invisible system: the power grid. Buildings, transportation, communication networks, and water and sanitation services all depend on a constant, reliable flow of electricity. Urban areas already account for 75% of global energy consumption14, and total electricity demand is expected to rise sharply as cities grow taller, denser, and more connected.
But the global grid is under pressure. Aging infrastructure, surging digital demand, and the shift to electric transportation are pushing current systems to their limits. With the rapid growth of AI usage and data centers, grids will need to double or even triple in capacity and resilience.
This challenge, however, also presents an opportunity. Dense urban areas enable economies of scale in energy distribution and clean technology deployment. Technologies like rooftop solar, district heating, and smart grid systems become more efficient and cost-effective when implemented at scale, allowing cities to reduce energy waste and better manage demand.
But while emissions may decline with the shift to clean energy, renewable systems are far more material-intensive than fossil fuels. Scaling these systems fast enough to meet urban growth will require a reliable and greatly expanded supply of critical minerals.
Copper
Used in generation, transmission, distribution, and energy storage, copper forms the foundation of the power grid. Solar panels and wind turbines require almost three tonnes of copper per megawatt of installed capacity15, and as clean energy sources expand, copper demand is set to rise dramatically.
Another facet of copper demand is its use in transmission and distribution networks, which are projected to require two million tonnes of the metal annually by 203016, due to grid modernization and new electrification infrastructure. Overall, copper use in the power sector is expected to grow by 69% by 2050, from 5.5 million tonnes per year in 2021 to 9.3 million tonnes17, driven largely by renewable power systems and the infrastructure needed to connect them to end users.
Nickel
As discussed above, nickel is essential to batteries. In addition to powering electric vehicles, nickel-based batteries are widely used in grid-scale energy storage systems to stabilize renewable energy sources like wind and solar. Nickel is also a key material in nuclear power infrastructure, making up 25% of metals used18 in high-performance alloys that can withstand extreme temperatures and corrosive environments found within nuclear facilities. With renewed global interest in nuclear energy, especially in Asia, nickel is expected to face persistent supply pressure. The International Energy Association (IEA) predicts that nickel’s use in clean energy production will grow from 0.5Mt in 2023 to 3.6Mt by 204019.
Zinc
Zinc plays a less visible but equally critical role in energy infrastructure. Galvanized steel structures used in transmission towers, wind turbine and solar panel components, contributing to structural durability and longevity in often-harsh weather conditions. Zinc demand from wind turbines alone is expected to rise from 735 thousand tonnes per year in 2024 to 1.7 million tonnes in 205020.
Beyond its role in structural applications, zinc is also gaining attention for its potential in energy storage technologies. Zinc-based battery technologies are being explored and could emerge as alternatives to lithium-ion batteries for stationary energy storage.
Silver
Although it is more widely recognized as a precious metal, Silver plays a critical role in renewable energy power generation due to its exceptional electrical conductivity—the highest of all metals. It is a key component in photovoltaic (PV) cells used in solar panels. With total solar capacity set to exceed 7 TW by 2030 to meet rising clean energy demand, demand for silver in PV for solar is forecasted to increase by almost 170% by 2030, to about 273 million ounces, one-fifth of total silver demand.21, 22
In addition to solar energy, silver is utilized in various electrical applications, including batteries, conductors, and smart grid technologies, thereby reinforcing its importance as a strategic commodity in the transition toward low-carbon energy systems.
Economies of scale and the promise of cities
As populations around the world modernize and urbanize, infrastructure needs are growing rapidly. Cities are expanding, economies are digitizing, and governments are racing to build sustainable systems that can support growing urban populations.
This transformation has the potential to create higher standards of living for billions of people, but it comes with a material cost. The ability to build sustainable housing, transportation, electric grids, and digital networks relies on vast quantities of copper, nickel, zinc, and other critical materials. Every effort to make cities more livable by reducing emissions, improving mobility, and expanding public services increases demand for the raw materials that make those improvements possible.
Meeting future needs requires a steady, responsible increase in global metals production. Planning for future metals demand and investing in the supply chains that meet it responsibly and sustainably will be one of the defining industrial challenges of the 21st century.
Sources:
1. https://www.weforum.org/stories/2019/09/mapped-the-dramatic-global-rise-of-urbanization-1950-2020/
2. https://www.un.org/uk/desa/68-world-population-projected-live-urban-areas-2050-says-un
3. https://www.destatis.de/EN/Themes/Countries-Regions/International-Statistics/Data-Topic/Population-Labour-Social-Issues/DemographyMigration/UrbanPopulation.html
4. https://nickelinstitute.org/en/blog/2020%E5%B9%B4/april/functional-facades-help-tackle-building-emissions/
5. Wood Mackenzie: Global copper strategic planning outlook – Q2 2025
6. https://nickelinstitute.org/en/nickel-applications/stainless-steel/
7. https://worldstainless.org/wp-content/uploads/2025/02/ISSF_Stainless_Steel_in_Figures_2020_English_public_version.pdf; assuming some metal products are also used in construction
8. Wood Mackenzie: Global nickel strategic planning outlook – Q2 2025
9. Wood Mackenzie: Global zinc strategic planning outlook – Q2 2025; with Appian analysis
10. https://en.wikipedia.org/wiki/Belt_and_Road_Initiative
11. https://www.bhp.com/news/bhp-insights/2024/09/how-copper-will-shape-our-future
12. https://worldstainless.org/wp-content/uploads/2025/02/ISSF_Stainless_Steel_in_Figures_2020_English_public_version.pdf
13. Wood Mackenzie: Global nickel strategic planning outlook – Q2 2025
14. https://www.iea.org/reports/empowering-urban-energy-transitions/executive-summary
15. https://www.visualcapitalist.com/sp/why-copper-and-nickel-are-the-key-metals-for-energy-utopia/
16. https://www.visualcapitalist.com/sp/why-copper-and-nickel-are-the-key-metals-for-energy-utopia/
17. https://www.miningvisuals.com/post/bhp-projects-70-rise-in-copper-demand-by-2050-electrification-and-tech-revolution-lead-the-way
18. https://www.iea.org/reports/the-role-of-critical-minerals-in-clean-energy-transitions/executive-summary
19. https://www.iea.org/data-and-statistics/charts/global-nickel-demand-in-the-net-zero-scenario-2023-2040
20. https://www.iea.org/data-and-statistics/data-tools/critical-minerals-data-explorer
21. https://www.solarpowereurope.org/insights/outlooks/global-market-outlook-for-solar-power-2025-2029/detail
22. https://www.wsj.com/articles/the-global-solar-power-boom-is-driving-a-surge-in-silver-demand-4ac20435
