Fully electric vehicles are well-known for their zero tailpipe emissions, though their green credentials have been questioned for the environmental friendliness of the processes in harvesting raw materials for the vehicles’ batteries. New research has found that a growing electric vehicle population could bring about a shortage in natural resources as well as further pollution, Car Advice reported.

The move towards battery-electric vehicles is increasing demand for the base metals used in batteries such as nickel, cobalt and copper, and shortages in supply for these metals are expected to emerge as soon as 2025, a study by a coalition of Canadian researchers was quoted by the report.

A solution to these predicted shortages is in the deep sea mining of selected underwater rock concretions which can offer the materials required for electric vehicle battery production, though without the associated toxic waste from the process of producing them, it said.

Car Advice also noted that the study was commissioned by deep-sea mining company DeepGreen, which has a vested interest in the proposed harvesting method. This research has found that a vehicle with a 75 kWh battery with NMC 811 (nickel-manganese-cobalt) chemistry requires 56 kg of nickel, 7 kg of manganese and 7 kg of cobalt, as well as 85 kg of copper for wiring.

The issue with the harvesting of these materials is that the land ores they come from have limited yield, and conventional mining processes produce ‘billions of tonnes’ of waste while leaking toxins into soil and water, the study said. However, metals are recyclable, and as enough metal stock-in-use is built up over time to cover our needs, there should be enough stock to recycle through the system, it added.

The proposed deep-sea mining method takes aim at metals known as polymetallic nodules or ‘ocean nodules’, found in the sea floor of the Pacific Ocean, reported Car Advice. These rock masses contain high concentrations of nickel, cobalt and manganese, and have been described as ‘effectively an EV battery in a rock’ for being composed of the same metals required in an EV’s drive batteries.

Unlike metal ores harvested on land, ocean nodules contain no toxic levels of harmful elements, and mining these metals generates almost zero solid waste, the report noted. Compared with mining on land, ocean nodules deliver a carbon footprint that is 70% smaller, a full 100% reduction in solid waste, 84% less land use and risk to wildlife is reduced by 93%, it said.

A European investigation has found that in order to meet the United Kingdom’s targets for electric cars in 2050, nearly twice the current output of cobalt is needed, according to a report by the BBC. “It’s readily available on the seafloor, it’s almost like potato harvesting only 5km deep in the ocean,” EU project head Laurens de Jonge told the news channel.

Concerns regarding the impact of electric vehicles upon natural resources and the environment have been raised before, and work is already underway to get around future issues on this front, said Beyhad Jafari, CEO of Electric Vehicle Council in Australia.

“The development of batteries is where EVs have, in the past, been shot in the arm, and a few environmental and ethical issues have been raised. When it comes to the supply chain of metals there have been questions before about who’s digging them up and how, but now that large OEMs and reputable businesses have been put into this domain they’ve made sure they are reputable sources and are working to provide transparency in that market,” Jafari told Car Advice.

Contrary to reports of material shortages, studies investigating these resources often only account for present-day supply of these metals, which does not predict supply for the future, said Jafari, who added that supplies of these metals are likely to increase rather than decrease.

“If we look at the pipeline of investment going into making more of those metals, that’s actually been scaled back due to concerns of oversupply, not of undersupply,” he said. While the environmental credentials of EV batteries may still be questioned, development of electric vehicles will continue become more environmentally sound, Jafari continued.

“It’s a journey of good, better, best. You’ll hear detractors saying there are still emissions associated with EVs, but compared to what we have today with (internal combustion engines), we will still be in a better position,” he concluded.