Lithium production is often blamed for drying up freshwater in South America’s “Lithium Triangle” – a region of the Andes mountains in Chile, Argentina and Bolivia that contains most of the world’s lithium reserves. But a prolonged drought is probably behind most of the drying.
As a key component in batteries, lithium is critical to transitioning away from fossil fuels. Demand for the soft, white metal is projected to , according to the International Energy Agency. Already, demand paired with limited production has raised lithium prices to record levels as of 4 November, says at the Wilson Center, a US think tank. “We need the lithium and we need it fast,” she says.
Water used for lithium production has become a particular worry in an arid salt flat in Chile called Salar de Atacama. The high-altitude basin contains around 40 per cent of the world’s lithium reserves in about 3000 square kilometres.
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“It’s one of the driest places on Earth,” says at the University of Massachusetts Amherst. And since lithium production started there in the mid-1980s, it has become even drier. Losses to both groundwater and surface water have threatened communities of Indigenous Atacameño people, as well as unique ecosystems and species, such as the Andean flamingo, says Moran.
Lithium production is an intuitive culprit for the drying. Mining companies Albemarle and SQM produce lithium on the salar by pumping millions of litres of hypersaline water – a natural brine that contains lithium, potassium and other materials – from underground, then evaporating water from the brine to concentrate the valuable salts in a grid of aquamarine pools.
But the link between lithium and drying in the salar isn’t straightforward. Any impacts have to be distinguished from the effects of drought and other water use in the region, says Moran. The same holds true for other arid lithium reserves from Nevada to the Tibetan plateau.
He and his colleagues from mining companies and other water users in the salar between 2014 and 2020. In 2014, lithium and potash production used an estimated 8 per cent of freshwater allocations, while copper mining used almost half and irrigation used 27 per cent. In 2020, copper mining stopped using freshwater, shifting lithium’s share of allocations to 9 per cent and irrigation to 59 per cent.
A spokesperson for Albemarle says freshwater is used in lithium production only for washing equipment. SQM did not respond to a request for comment.
Physical measurements showed changes to fresh groundwater reflected this use, with the largest losses in areas with copper mining and agriculture, and the smallest losses in areas with lithium extraction.
Surface water, however, was affected more by changes in precipitation than groundwater. During several prolonged droughts since 2003, the researchers found that surface water decreased. In recent, wetter years, surface water increased, even as lithium production continued.
This is because freshwater and brine are largely “in different water worlds”, says at the University of Massachusetts Amherst, a co-author of the study. He says most freshwater flows across the salar like “water on top of pavement”, while the brine, accumulated over thousands of years, is disconnected from what happens at the surface.
The team’s analysis of hydrogen and oxygen isotopes in surface and groundwater showed that water in the lithium-rich brine arrived at least 65 years ago, while freshwater was mostly from new precipitation.
“There’s this perception that lithium production at the Salar de Atacama is drying up the place,” says Boutt. But the droughts alone – which may be related to a once-in-a-millennium megadrought underway in the region – can explain the drying observed so far, he says.
The research was funded by car manufacturer BMW and chemical company BASF, though Moran says the firms did not direct the research. “We just looked at the science and that’s it,” he says.
at the University of Antofagasta in Chile says lithium production isn’t only a concern because of freshwater use. Unique microbial communities use the brine itself, and the mining projects are massive undertakings that disrupt ecosystems with roads, noise and dust, she says. Lithium production can also contaminate freshwater if not done carefully.
“They see it as a reservoir of minerals,” says Dorador of proponents for expanding lithium production to other salares in the Lithium Triangle. “Not as an ecosystem to be protected.”
