How can we decarbonize copper and nickel mining?
Top Image: By 2050, the annual supply of copper and nickel will have to increase by about 150 to 200 percent.
We are at the beginning of a green technological revolution, according to the United Nations Conference on Trade and Development. The transition to a low-carbon economy to mitigate climate change would not be possible without green technologies like electric vehicles, solar panels, wind turbines, and energy storage systems. However, these technologies rely on over 10 different minerals and metals—including copper, nickel, cobalt, and aluminum—whose production must increase significantly to meet demand.
By 2050, the annual supply of copper and nickel, in particular, will have to increase by about 150 to 200 percent relative to 2020 production levels to meet the needs of green technology deployments. If production grows rapidly, the associated environmental impacts and greenhouse gas (GHG) emissions are expected to rise as well. Under a business-as-usual scenario, the GHG emissions of copper and nickel may increase by 125 and 90 percent, respectively, by 2050. Therefore, decarbonizing the mining industry is an essential part of meeting global climate targets.
How mining affects the environment
Mining is an environmentally invasive process. Its impacts manifest in land use change, disturbance to local ecosystems, and GHG emissions, says Paolo Natali, a principal with RMI’s climate intelligence program who leads the Supply Chain Emissions Initiative. The nature of mining is to disturb large areas of land to retrieve resources deep below the surface, that’s why it can drive deforestation and increase the erosion rate greatly. Waste rock and tailings from mining may also contaminate the soil and water, which, combined with the clearing of forests, contributes to habitat loss and ecosystem damage.
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Mining is also a significant source of GHG emissions due to the use of diesel-powered equipment, which releases carbon dioxide, as well as through the release of trapped gasses like methane, says Natali. The supply chain is also energy-intensive because activities like drilling and blasting, material handling or the process of moving the mined material out of the mine via conveyor belts or trucks, grinding, metal smelting, and transporting all require a lot of energy.
Natali says copper and nickel extraction, in particular, are experiencing declining ore grades. Ore grades refer to the concentration of the mineral or metal content in an ore-bearing rock. Declining grades means that it’s taking more effort to gather the same amount of mineral, and therefore using up more energy and resulting emissions, he adds. As the ore grade decreases, the energy, diesel, and electricity used all increase. The finite nature of these resources—which makes it necessary to go deeper and into more remote areas to keep finding them—and the economies of scale that the mining industry has developed have enabled lower grades to be processed profitably, says Natali.
Increasing the production of copper and nickel to address the growing need for green technologies would increase the impacts of mining and harm the environment even further. Perrine Toledano, the director of research and policy at the Columbia Center on Sustainable Investment, says meeting the rising mineral demand will put pressure on freshwater resources in copper mining regions and present a significant biodiversity risk in locations with nickel reserves. Chile, the world’s top copper producer, is already water-scarce and will face increasing water risks due to the impacts of climate change.
Overall, decarbonizing mining is necessary to successfully transition to a low-carbon economy.
Decarbonizing copper and nickel mining
To cut emissions associated with carbon-intensive energy production, the industry should replace fossil fuels and its generated electricity with renewable energy, sustainable biofuels, and green hydrogen, says Toledano. For instance, eliminating diesel use in mining equipment may remove up to 40 percent of a mine site’s emissions.
Aside from using clean electricity, Natali says adopting higher precision mining techniques to improve ore grades and electrifying the energy input, like by using conveyors or electric trucks during material handling, are crucial. Latest developments in battery electric large-haul trucks, such as fast charging or hydrogen fuel-cell range extenders, will have to be coupled with the increasing use of renewable energy and new technologies downstream to eliminate emissions from high temperature and chemical processes like smelting and refining, he adds.
Circular economy interventions like increasing metal recovery and reusing mineral and non-mineral waste may also support emission reductions across the mining value chains. Both copper and nickel can be recycled repeatedly without losing their properties or quality. Moreover, recycled copper uses about 85 percent less energy than primary production.
Policymakers can support a just transition to net zero mining by establishing stricter and clearer regulation of mining activities and subsidizing green energy, says Natali. He also recommends requiring that imported minerals face similar environmental and social standards with domestically produced minerals.
Fossil fuel subsidies in place create an artificial cost disadvantage for renewables, says Toledano. Such subsidies reduce the cost of fossil-fuel-powered electricity generation, which makes renewable energy less competitive. They can also reinforce the reliance on fossil fuels and make it more favorable. Therefore, policymakers must ensure the penetration of renewable energies, which could support the transition of the mining industry to clean energy.
Decarbonizing copper and nickel mining won’t happen in an instant. However, by switching to renewable energy, improving production efficiency, and establishing policies that include climate-related mitigation and adaptation obligations on mining operations, meeting increasing mineral demand with fewer emissions may become achievable.