The world needs more battery metals. It’s time to dig up the seabed
Burning fuel to move people and goods on the road produced about 6bn tonnes of carbon dioxide in 2021, 16% of global emissions related to energy. If countries are to reduce global warming, they must stop these emissions. That means building battery-powered vehicles that run on electricity rather than internal combustion. And that in turn means mining and processing metals on an unprecedented scale.
Take nickel, which is used in the part of the battery that stores energy. The International Energy Agency believes that 80m tonnes of it must be mined between now and 2040 if the world is to meet climate targets. That’s more nickel than has ever been mined, and approaches the 100m tonnes of unmined global reserves estimated by the United States Geological Survey.

It is a truism among resource economists that new demand creates new reserves, as price signals encourage exploration and innovation. But that takes time, and there is an urgent need. Fortunately, there is a large untapped source of metal. A part of the sea floor in the Pacific Ocean, called the Clarion-Clipperton Zone (CCZ), about 4,000 meters deep, holds an incredible 340m tonnes of nickel. The problem is that the rules on seabed mining, said the International Seabed Authority (ISA), army of the one, has been working on it for 29 years, held back by a weak bureaucracy and the skeptical concerns of conservatives. On July 9 the deadline for the completion is likely to be missed. The is the rules must be published as soon as possible, so that mining can begin.
Nickel sits on the sea floor in potato-sized lumps called nodules, bound by cobalt, copper and manganese, which are also present in more than enough quantities to meet the needs of the green energy movement. The nodules were formed over millions of years when metal particles drifted down and collected together on the sea floor. They can be evacuated using bus-sized robots, and then pumped to a ship on the surface.
Conservationists say this process poses a serious threat to the environment. Carbon will be kicked up from the sea floor and make its way into the atmosphere, they argue, generating more warming; life-suffocating plumes of sediment will be created by the collection system and hitherto untouched CCZ ecosystems will be destroyed, disrupting food webs and harming fisheries.
But on closer inspection many of these arguments are false. When it comes to nickel, mining the CCZ it is greener and cleaner than dry land mining. Research shows that the amount of carbon stored in the ccz very little, meaning that not enough mineralization will be released into the atmosphere to contribute to warming. And, according to research from the Massachusetts Institute of Technology, the deposited sediment does not spread as far or as thick as it is claimed.
The most serious concern is the threat to different organisms that science does not know. But life in the CCZ scarce – about 270,000 tonnes of biomass would be destroyed by mining – and mostly microbial. And because the CCZ the last stop of the ocean food web, there would be little spillover to other ecosystems. Contrast that with the situation in Indonesia, the country that controls the supply of nickel and holds a fifth of all reserves. If all these reserves were mined, at least 10m tonnes of living organisms would be destroyed (as in the CCZ, mostly species unknown to science). The associated emissions would also be ten times higher.
several ISA members have called for a “precautionary pause”, arguing that little is known about the impact of CCZ mining This logic is backwards. We know too much about the dire need for nickel, and the environmental devastation wrought by its extraction, for anything other than careful but swift action to be a sensible course of action. Battery technologies that use less nickel – or even none at all – could reduce the need over time, but current trends demand a lot. Member states should therefore try to finalize the rules as soon as possible, and then monitor the impact on the CCZ and the surrounding ocean as mining takes place. The reward is a cooler planet that hosts more abundant life. ■