A battery is not zero-impact

Water, carbon, biodiversity, toxicity and labor, seen without losing sight of electrification's benefits.

Climate benefit and material impact can coexist

Two truths that do not cancel each other out

A battery allows integrating electricity from variable sources like solar and wind, and allows moving vehicles without combustion on the street. That reduces oil consumption, local noise and direct emissions over years of use — a real, measurable advantage. Manufacturing that same battery, however, concentrates considerable environmental impact at the start of its life, long before it starts delivering that benefit. Neither truth cancels the other: both are true at the same time, and the pedagogically honest question is not which one "wins," but how they compare with the real alternative the battery replaces.

Water: the same liter is not worth the same everywhere

Mining and refining lithium, cobalt, nickel and other battery materials uses water for brine pumping, separation processes, dust control at mines, ore washing and numerous refining chemical processes. The real effect of that consumption depends radically on the watershed where it occurs: a liter of water consumed in a humid region with abundant resources does not carry the same environmental cost as a liter consumed in an arid salt flat where that water is a scarce resource contested between mining, agriculture and local communities. According to the International Energy Agency, more than half of current global lithium and copper production is concentrated precisely in high water-stress areas — a fact that completely changes how any figure of "liters of water per tonne of lithium" should be read without that geographic context.

Land, waste and biodiversity: the risk does not end at digging

A mine, the access roads connecting it, waste-rock dumps and tailings deposits fragment natural habitats directly and immediately. But the environmental risk does not end when excavation stops: sludge and wastewater from a mine must remain stable, contained and controlled for years or decades after extraction activity has ceased, because a failure at a tailings deposit can suddenly release toxic materials accumulated over the operation's entire life. Subsequent land restoration reduces the damage and can return part of its ecological function to the site, but does not immediately recreate the complex ecosystem that existed before the mine.

People: real benefits, real risks, in the same chain

Mining and refining battery materials generates employment, income and, in many cases, contributes to electrifying regions that previously lacked reliable energy access — real social benefits it would be dishonest to ignore. At the same time, there are documented risks of workplace accidents, exposure to hazardous substances, corruption in managing mining revenues, forced displacement of communities, and human rights violations in supply chains with weak or insufficiently audited governance. A slogan like "cobalt-free" — a partial response to concerns about artisanal cobalt mining in some regions — does not automatically mean a problem-free chain: it simply shifts attention to other materials, such as nickel or lithium, and to other geographic regions where analogous, different but equally real risks may exist.

The right question: compared with what?

A large electric car needs a bigger battery than a small one; both can avoid fuel during use, but neither beats walking, cycling or a well-occupied public transport in materials. A home battery may help the grid or barely get used, depending on tariffs, control and context.

Reduce impact with reasonable size, long life, clean electricity, auditable suppliers, repairable design and collection. And keep perspective: improving batteries does not replace reducing unnecessary trips, oversized vehicles or wasteful electricity demand.

The numbers, with their source

When mining competes for the water of an entire region

At the Salar de Atacama (Chile), one of the world's largest lithium deposits, some estimates put mining's water consumption at up to 65% of the region's available water — a figure that, while it varies between sources and methodologies, points to real pressure on a desert ecosystem where water is, by definition, scarce. Producing a single tonne of lithium carbonate at this specific location requires evaporating approximately 500 m³ of brine, a process that stretches over months in open-air solar ponds.

Sources: Mongabay — Lithium mining leaves severe impacts in Chile; ScienceDirect — Water footprint of battery-grade lithium production in the Salar de Atacama.

More than half the world's lithium and copper, in water-stressed areas

According to the IEA's analysis of critical mineral supply chains, more than half of current global lithium and copper production is concentrated in regions classified as high water stress. This means the real impact of water consumed by battery mining cannot be meaningfully averaged globally: it depends critically on which specific watershed each mining operation occurs in.

Source: IEA — Reducing the impact of extractive industries on groundwater resources.

The table connecting water, carbon and land

What this table is missing

No water or carbon figure alone captures labor conditions, institutional governance, or how economic benefits are shared between the local community and the operating company — equally relevant dimensions that are rarely quantified with the same precision as water or carbon, precisely because they are harder to measure in a standardized way across different countries and operations.

Sources

• The IEA gathers risks around water, biodiversity, human rights and communities.
• The IEA explains that copper and lithium are especially exposed to water stress.
• EV battery supply chain sustainability compares chemistries, manufacturing, use and recycling.