The energy from sunshine and wind is obviously clean, however, the infrastructure we need to capture it is not. The transition to renewables is going to require a dramatic increase in the extraction of metals and rare-earth minerals.
The ecological and social costs associated with this work is real.
In 2017, the World Bank released a little-noticed report that offered the first comprehensive look at this question. It models the increase in material extraction that would be required to build enough solar and wind utilities to produce an annual output of about 7 terawatts of electricity by 2050.
Using wind, solar, and energy storage batteries as proxies, the study examines which metals will likely rise in demand to be able to deliver on a carbon-constrained future. Metals which could see a growing market include aluminum (including its key constituent, bauxite), cobalt, copper, iron ore, lead, lithium, nickel, manganese, the platinum group of metals, rare earth metals including cadmium, molybdenum, neodymium, and indium—silver, steel, titanium and zinc. The report then maps production and reserve levels of relevant metals globally, focusing on implications for resource-rich developing countries.
By doubling the World Bank figures, we can estimate what it will take to get all the way to zero emissions: 34 million metric tons of copper, 40 million tons of lead, 50 million tons of zinc, 162 million tons of aluminum, and no less than 4.8 billion tons of iron.
As the world goes crazy trying to replace fossil fuels with clean energy, the environmental impact of finding all the lithium required to enable that transformation could become a serious issue in its own right. One of the biggest environmental problems caused by our endless hunger for the latest and smartest devices is a growing mineral crisis, particularly those needed to make our batteries.
In South America, the biggest problem is water. The continent’s Lithium Triangle, which covers parts of Argentina, Bolivia and Chile, holds more than half the world’s supply of the metal beneath its salt flats. It’s also one of the driest places on earth. To extract lithium, miners start by drilling a hole in the salt flats and pumping salty, mineral-rich brine to the surface.
Then they leave it to evaporate for months at a time, first creating a mixture of manganese, potassium, borax and lithium salts which is then filtered and placed into another evaporation pool. After between 12 and 18 months, the mixture has been filtered enough that lithium carbonate can be extracted.
The process uses approximately 500,000 gallons of water per tonne of lithium. In Chile’s Salar de Atacama, mining activities consumed 65 per cent of the region’s water, which impacts local farmers – who grow quinoa and herd llamas – in an area where some communities already have to get water driven in from elsewhere.
Toxic chemicals also leak from the evaporation pools into the water supply. These include chemicals, including hydrochloric acid, which are used in the processing of lithium into a form that can be sold, as well as those waste products that are filtered out of the brine at each stage. In Australia and North America, lithium is mined from rock using more traditional methods, but still requires the use of chemicals in order to extract it in a useful form. Research in Nevada found impacts on fish as far as 150 miles downstream from a lithium processing operation.
Like any mining process, lithium mining is invasive, it scars the landscape, it destroys the water table and it pollutes the earth and the local wells. Is this really a green solution?
According to a report by Friends of the Earth, lithium extraction inevitably harms the soil and causes air contamination. In Argentina’s Salar de Hombre Muerto, locals claim that lithium operations have contaminated streams used by humans and livestock, and for crop irrigation. In Chile, there have been clashes between mining companies and local communities, who say that lithium mining is leaving the landscape marred by mountains of discarded salt and canals filled with contaminated water with an unnatural blue hue.
Cobalt and nickel, also used in electric vehicles, offer a potentially huge environmental cost. Cobalt is found in huge quantities right across the Democratic Republic of Congo and central Africa, and hardly anywhere else. The price has quadrupled in the last two years.
Unlike most metals, which are not toxic when they’re pulled from the ground as metal ores, cobalt can be poisonous in excessive doses.
The Congo is home to ‘artisanal mines’, where cobalt is extracted from the ground by hand, often using child labour, without protective equipment.