Copper mining remains highly water-intensive, with huge deposits in Andean regions impacting local flora and fauna, as well as generating light pollution in areas known for their night skies.

Chilean copper giant Codelco, under increasing pressure from global customers demanding a smaller environmental footprint, is trying to move to a greener outlook by investing in electric buses, nurseries and recycling of unused materials.

The world's largest producer of the red metal, struggling to reverse a decline in output, has focused its campaign on its flagship El Teniente mine, about 75 kilometres south of the capital Santiago.

Behind the plan are global customers increasingly seeking greater traceability of copper and the components used to make their products, from electric cars to wind turbines.

"There is no doubt that this is increasingly in demand, and that is why we consider the certifications we have to be a fundamental asset, such as The Copper Mark. This is obviously increasing over time, but it is certainly a trend," said Codelco CEO Rubén Alvarado.

Codelco has set sustainable goals for 2030 that it needs to meet.

Copper is a key metal for decarbonisation and the energy transition, along with lithium, another metal that the company is also beginning to explore.

The true environmental impact is less clear, experts said. Copper mining remains highly water-intensive, with huge deposits in Andean regions impacting local flora and fauna, as well as generating light pollution in areas known for their night skies.

"Perhaps the contribution is still marginal, but everything starts like this, at least first generating concern. Second, being accompanied by some legislation," says Patricia Muñoz, an economist in the Department of Mining Engineering at the University of Santiago.

To make the mine more environmentally friendly, a hundred electric buses now transport workers from the nearby city of Rancagua.

"This fleet is currently avoiding around 3,000 tons of CO2 annually. It also means that all personnel transportation within the tunnels is zero-emission and therefore has better air quality," said Ricardo Repenning, co-founder of Reborn, the electric bus company.

This company is now advancing in studies to implement an option powered by green hydrogen, which would triple the autonomy of electric vehicles.

Other new systems involve taking used bolts and mesh from tunnels and truck wheels to recycle and reuse them in the mine.

"Clearly the economic value of this is a little more expensive, because there are transportation costs involved, but we believe that as long as we continue doing this, we will make our process more efficient, and we will also take charge of these environmental liabilities," said Andrés Music, general manager of El Teniente.

The firm also works with the government on a nursery and research centre to produce native species, including cacti for conservation, as well as to help regenerate areas damaged by flooding or mine tailings dams.

"That is the mandate I now have with Codelco, to produce one million native plants, especially from the sclerophyllous forest," said Iván Quiroz, head of the Mediterranean Ecosystems Research Center (CEIEM).

"We want to contribute to the recovery of tailings with different species, not only trees, but we must start with stabilization so that the articulated material does not disappear and also contribute with material that is capable of growing and that extracts these heavy metals," he said.