PDONE BY THE Due to the threat of climate change, rich countries are embarking on a major electrification project. Britain, France and Norway, among others, plan to ban the sale of new combustion engine cars for the next ten years. Even where prohibitions are not in the law books, sales of electric cars are growing rapidly. Power grids are also changing, as wind turbines and solar panels displace fossil fuel power plants. The International Energy Agency (IEA) expects the world to add as much renewable energy over the next five years as it has in the past 20 years.
That means all batteries, and lots of them – both to power the cars and to store energy from intermittent renewable power plants. The demand for the minerals from which those batteries are made is increasing enormously. Nickel in particular is scarce. The element is used in the cathodes of high-performance electric car batteries to increase capacity and reduce weight. The IEA calculates that the world would need to produce 48 million tons of the material each year by 2040 to meet its low-carbon goals, about 19 times more than it does today. That amounts to between 300 and 400 million tons of metal in total between now and then.
Over the past five years, most of the growing demand has been met by Indonesia, which has bulldozed rainforests to get to the ore below. In 2017, the country produced only 17% of the world’s nickel, according to CRU, a metal research company. Today it accounts for 54%, or 1.6 million tons per year, and that number is still rising. CRU believes the country will account for 85% of global output growth between now and 2027. However, that is probably not enough to meet the rising demand in the world. And as Indonesia’s nickel production increases, it is expected to replace palm oil production as the leading driver of deforestation in the country.
But there is an alternative. A stretch of seafloor in the Pacific Ocean called the Clarion-Clipperton Zone (CCZ) is littered with trillions of potato-sized lumps of nickel, cobalt, manganese and copper, all of which are of interest to battery manufacturers (see map). Collectively, the nodules alone contain an estimated 340 million tons of nickel — more than three times the U.S. Geological Survey’s estimate of the world’s terrestrial reserves. Companies have been eager to mine them for several years. With an international bureaucratic deadline approaching July 9, that prospect seems more likely than ever.
Honey, it’s better where it’s wetter
That date marks two years since the island nation of Nauru, on behalf of a mining company it sponsors called The Metals Company (TMC)told the International Seabed Authority (IS A), an appendage of the UNthat it wanted to mine part of the mine CCZ to which it has been granted access. That led to a requirement for the IS A to establish rules for the commercial exploitation of the deposits. If those regulations aren’t ready by July 9 — and it looks like they won’t be — then the IS A is required by law to “consider and provisionally approve” TMC‘s application. (The company itself says it hopes to wait until an agreement can be reached on the rules.)
TMC‘s plan is about as simple as underwater mining can be. The first target is a patch of the CCZ called NORI-D, which covers about 2.5 million hectares of seabed (an area about 20% larger than Wales). Gerald Baron, TMC‘s boss, estimates there are about 3.8 million tons of nickel in the area. Since the nodules are just sitting on the ocean floor, the company plans to send a large robot down to the sea floor to suck them up. The collected nodules are then sucked to a surface support vessel through a high-tech pipe, similar to those used in the oil and gas industry.
The support vessel will wash away any sediment and then take the nodules to a second vessel that will take them back to shore for processing. The excess sediment, meanwhile, will be discharged back into the sea at a depth of about 1,500 meters, well below most ocean life. That’s not true either TMC the only company interested. A Belgian company called Global Sea Mineral Resources – a subsidiary of Deme, a dredging giant – is also excited and has tested a seabed robot and riser system similar to TMC‘s. Three Chinese firms – Beijing Pioneer, China Merchants and China Minmetals – are also circling, although they are believed to be further behind technologically.
As with land-based mining, extracting nickel from the seabed will damage the surrounding ecosystem. Although the CCZ is deep, dark and cold, it is not lifeless. TMCThe robot’s robot destroys all organisms on the seafloor it drives over, as well as creatures that live off the nodules it collects. It will also raise sediment plumes, some of which will float to and kill nearby organisms (although research from MIT shows that these plumes usually do not rise more than two meters above the sea floor). Adrian Glover, a marine biologist at the Natural History Museum in London, points out that because life first developed in the oceans and only later moved to land, most of the planet’s genetic diversity can still be found underwater is. Although the deep-sea floor is dark and nutrient-poor, it is nevertheless home to thousands of unique species. Most are microbes, but there are also worms, sponges and other invertebrates. The diversity of life is “very high,” says Dr. Glover.
Still, mining on the seabed is more environmentally friendly than mining in Indonesia in several respects. The harsh deep-sea environment means that highly diverse life is not very abundant. An article published in Nature in 2016 found that a certain square meter of CCZ supports between one and two living organisms, weighing up to a few grams. A square meter of Indonesian rainforest, on the other hand, contains about 30,000 grams of plant biomass alone, and much more if you also include primates, birds, reptiles and insects.
But it is not enough to simply weigh the biomass in each ecosystem. The amount of nickel that can be produced per hectare is also relevant. The 2.5 million hectares that TMC hopes to exploit is expected to yield about 3.8 million tons of nickel, or about 1.5 tons per hectare.
Getting hard numbers for land-based mining is tricky, because the companies doing it are less transparent than those hoping to harvest the seabed. But research reports from the Pulitzer Center, a nonprofit media outlet, suggest that every acre of rainforest on Sulawesi, the Indonesian island at the center of the country’s nickel industry, will produce about 675 tons of nickel. (One reason terrestrial deposits produce so much more nickel, despite the lower quality of the ore, is because the ore extends well below the surface, while nodules are found only on the seafloor.)
All this allows for a very rough comparison. For every ton, about 13 kilograms of biomass would be lost CCZ nickel mined. Each ton mined on Sulawesi alone would destroy about 450 kg of plants, plus an unknown amount of animal biomass.
There are other environmental arguments in favor of mining on the sea floor. The nodules contain much higher concentrations of metal than land-based deposits, meaning less energy is required to process them. Peter Tom Jones, the director of the KU The Leuven Institute for Sustainable Metals and Materials, in Belgium, estimates that processing the nodules into usable metals will produce about 40% less greenhouse gas emissions than that of terrestrial ore.
And because the nodules have to be removed for processing, companies like that TMC can be encouraged to choose locations that provide energy with low emissions. In contrast, Indonesian nickel ore is uneconomical unless it is processed near the mines from which it was extracted. That almost always means using electricity generated by burning coal, or even diesel generators. Alex Laugharne, an analyst at CRU, estimates that for every ton of nickel, Indonesian nickel production emits about 60 tons of carbon dioxide that warms the planet. An audit of TMCThe plans from Benchmark Minerals Intelligence, a company based in London, showed that every ton of nickel harvested from the seabed would produce about six tons of CO2.
In any case, metal collected from the seabed is unlikely to fully replace that mined from the rainforest. Battery production is growing so fast that nickel is likely to be dug up everywhere. But if the ocean tubers can be affordably marketed, the huge amount of available metal could ease the strain on Indonesia’s forests. And such arguments are unlikely to remain theoretical for long. Mr Baron van TMC wants to start commercial production of nickel and other metals from the seabed at the end of next year. ■