Frequently Asked Questions
We don’t need to go to the deep sea for battery metals because there are enough resources on land.
While there are technically enough metal-bearing deposits on land to meet the needs of the planet, it does not mean that they can be extracted economically, or that they can or should be permitted given the associated costs to the planet and people.
Access to—and development of—land-based deposits is increasingly difficult. Falling grades means digging deeper and wider for lower-quality ores, spending more capital to get the same amount of metal. Nickel, cobalt, and manganese deposits are located in some of the planet’s most biodiverse places, including Indonesia, the Democratic Republic of Congo (DRC), and South Africa. In the DRC in particular, cobalt mining often involves child labor. Most of battery-driven growth in nickel supply is expected to come from nickel laterites beneath the rainforests of Indonesia and the Philippines. Scaling battery-grade nickel production from laterites will devastate terrestrial ecosystems, freshwater resources, and human communities.
Producing these metals from polymetallic nodules would eliminate or reduce most of the Environmental, Social, and Corporate Governance (ESG) costs of conventional metal production. Most of these reductions are driven by the characteristics of the nodules themselves: High grades of four metals are found in a single rock, so four times less ore needs to be processed to get at the same amount of metal. Nodules also contain no toxic levels of heavy elements, meaning the entirety of a nodule can be used, making zero-solid-waste production possible. Because nodules sit unattached on top of deep-sea sediment, they do not require drilling or blasting for retrieval.
We do not need to mine more metal. We can simply reduce our consumption and recycle.
We should reduce our consumption and recycle every atom of metal, but over the next 30 years, the impact of both measures on demand for mined metal will be marginal. Most new demand for mined metal is driven by the need to transition away from fossil fuels. Even if we recycle every single metal atom starting today, between 2020 and 2050, recycled copper, nickel and cobalt would meet only 26%, 23% and 15% of total metal demand, respectively. We can’t recycle what we don’t have. As long as the transition’s projected needs exceed existing stocks, we will need more metal.
The global light passenger fleet, which is currently 1.2 billion cars, is projected to increase to 2 billion by midcentury. Demand-side reductions such as carpooling or shared ownership will help reduce this business-as-usual projection but won’t negate the need to electrify the existing gas-guzzling fleet. A conventional internal combustion engine (ICE) car on average contains 5 times less selected metal mass than that required to build an electric vehicle (EV). Even if we recycled every existing gas and diesel car, and dramatically increased ride sharing and robotaxis, we would still need a significant new injection of virgin metals to transition from ICE cars to EVs.
Product redesign and circular-economy solutions should be pursued now and phased in so that they can be maximally leveraged as growth tapers off. We plan to build a global inventory and circular economy of metals to dramatically reduce—and eventually eliminate—the need to take metals from the planet. While this will take several decades, we believe it will be possible by the latter half of the 21st century.
Deep-sea mining will impact climate change by disrupting marine carbon sinks.
This claim is unfounded. Collectors operating in the abyssal zone at 4–6 kilometer depths will disrupt only the top 5 centimeters of sediment, separate it from nodules inside the machine and redeposit it at the seafloor. A majority of it resettles within days and hundreds of meters of origin. No known mechanism exists for this sediment to travel up the water column and reach the atmosphere. There are also no known methane hydrates in the Pacific Ocean’s Clarion Clipperton Zone , where we’re exploring. At abyssal zone depths, both inorganic carbon and methane are soluble in water, and neither forms bubbles that could rise to the surface.
Contrary to this claim, peer-reviewed research comparing the lifecycle climate change impacts of supplying 1 billion EVs with nickel, copper, cobalt, and manganese shows that using nodules to produce these metals, rather than getting them from land resources, would reduce associated climate change impacts by 90%.
Environmental and social impacts of land-based mining are well understood and can be addressed because operations on land are accessible. Deep-sea mining impacts are not understood and operations would be out of sight, out of mind.
Understanding and witnessing the environmental and social damages of land-based metal production is one thing, reducing them is another. The theoretical potential for reducing harm on land is severely constrained: We can’t change the fact that the grades of remaining ores are low and falling, nor can we change the fact that if the rock contains only 0.5% of target metal, the other 99.5% will become a waste stream. We also can’t change the fact that remaining battery metal deposits are located in places with high biodiversity, often on Indigenous land. The life-cycle Environmental, Social, and Corporate Governance (ESG) footprint for land-based production can be improved, but in most cases, it will always be much worse than the lifecycle ESG footprint of nodule-derived metals. This is simply because the starting point for the nodule resource is fundamentally different: rich concentrations of four metals in a single rock; an entirely usable rock mass; a barren and common, desert-like environment with limited life; and no threat to Indigenous land.
Additionally, the Clarion Clipperton Zone is physically remote, but will not be “out of sight, out of mind.” The Metals Company’s adaptive management system, a mix of deep-sea ecological data, marine sensors, and cloud-based A.I., will create a digital twin of our operating environment. This system will enable us to monitor what’s happening in real time and give eyes and ears into our offshore operations to the regulator and stakeholders. With this information, we can adapt, pause, and change our operations to stay within expected ecological thresholds and inform all stakeholders of our impacts at any point, from anywhere in the world.
Deep-sea mining will damage fragile deep-sea ecosystems.
Billions of tons of metal will be extracted from the planet over the next 30 years to make the clean-energy transition possible. Metal extraction—whether on land or from the deep sea—will impact ecosystems, but the extent and types of impacts are worth considering. The abyssal seafloor carries 300 to 1,500 times less life and stores 15 times less carbon than ecosystems on land. If we source battery metals from seafloor nodules, we can reduce destruction of more biodiverse ecosystems, like rainforests, which play a vital role in the Earth’s climate cycle. Importantly, the abyssal plain is the most common environment on the planet. As a precautionary measure, more area in the Clarion Clipperton Zone has already been set aside for conservation than is currently under exploration.
Adding a new supply of metals could undermine prices and incentives to scale up recycling.
Given the aggressive scale up of demand driven by the world’s transition to clean energy by 2050, metal shortages are likely to persist for some time as various metal producers make the heavy investments required to scale up supply. Once metal availability is no longer the key issue, metal producers will start competing on price and sustainability. At this point, we expect that recycled metal will start displacing metal supply from land-based sources due to its much better sustainability profile—even if it comes with a higher price tag. This scenario is further supported by the fact that many jurisdictions around the world are making recycling of EV batteries a regulatory requirement. If done right, recycled metal is the only truly sustainable source of metal.
Nodule-derived metal will likely co-exist with recycled metal for a few decades due to its lower production cost and lower ESG footprint, but will gradually be phased out as the world builds up sufficient metal stocks.
The deep sea is a pristine environment. It should not be touched.
No ecosystem is immune to the impacts of industrial society, including the deepest parts of the ocean. In its upper layers (0–2,000 meters), the ocean continues to warm unabated. It’s likely that this ocean warming impacts the deep sea. The ocean is also continuing to acidify as it absorbs more CO2 from the atmosphere. With this in mind, we view it as our primary focus to reduce the CO2 in our atmosphere, thereby reducing ocean warming and CO2 absorption into the oceans. This requires a massive and rapid injection of metals for batteries into the global economy.
The impacts of supplying this demand from conventional terrestrial sources will only deepen the degradation of our planet’s oceans and biodiverse ecosystems. Polymetallic nodules provide a better path forward that can curtail these impacts and meet the needs of the clean energy transition at the same time.
We know more about the moon than the deep sea.
This claim dates back to the 1960s—a time when we knew much less about both the moon and the deep sea—and it isn’t just a bad analogy, it’s wrong.
Throwaway claims like this one ignore the rich history of deep-ocean research. Marine biologists, ecologists, geologists, chemists, and physicists have explored the deep sea for decades and have made astounding progress in our understanding of the oceans over the last 50 years. The number of samples collected, expeditions undertaken, and areas mapped in the deep sea are in fact much higher than what we have for the moon. Thirty-nine people have visited the deepest parts of our oceans, thirteen of whom visited these environments long before Neil Armstrong ever set foot on the moon. While total oceanic mapping stands at only 18%, we’ve mapped a surface area twice the size of the moon underwater, at an average depth of 4,000 meters, and to a high resolution.
In addition, The Metals Company is funding independent, peer-reviewed research with over 75 discrete studies focusing on two goals: (1) baselining and understanding biodiversity and ecosystem function from the abyssal seafloor all the way through the water column and above the water surface and (2) characterizing and mitigating the impacts of our operations on the marine environment. In order to protect this part of the marine environment, we must first understand it more fully. You can learn more about our collaborative Environmental and Social Impact Assessment (ESIA) and deep-sea discovery program on our Research page.
We need a moratorium on deep-sea mining until the impacts of nodule collection are better understood.
Let’s be clear: No deep-sea mining takes place today. The only activity currently under way is deep-sea research focused on baselining marine environments and characterizing impacts. No commercial collection of seafloor nodules can or will take place until rigorous, multi-year environmental impact studies (ESIA) are conducted, vetted, reviewed and evaluated. If this research shows that the risks outweigh the benefits, the global community, through the International Seabed Authority (ISA), can decide that our project should not go ahead. In calling for a moratorium, NGOs risk undermining the very research they are calling for while the climate change clock continues to tick.
It’s worth noting that contractors like The Metals Company are commissioning the vast majority of deep-sea research right now. Our $75 million research program will result in hundreds of independent, peer-reviewed papers authored by independent researchers who contractually maintain their academic freedom. More on this can be found on our Research page.
If at the end of our ESIA program the research shows that producing critical battery metals from seafloor nodules will do more planetary harm than good, we will not seek to apply for an exploitation contract with the ISA and will assess other options.
Nodule collection could lead to the extinction of species in the deep sea.
While we cannot promise that no species will go extinct in the deep sea, we know we can do much better than the status quo. Mining on land has driven species extinction and biodiversity loss for centuries. Even in countries with stringent environmental regulations, biodiversity-related impact studies typically focus only on keystone species above ground. They do not consider biodiversity comprehensively and ignore the estimated 99% of microbial species and 80% of worm species yet to be studied under the soil. As mining increasingly moves into the most biodiverse ecosystems on the planet, species extinction and biodiversity loss will increase.
Nodule collection, by contrast, would take place at 4–6 kilometers depth on the abyssal plain of the Clarion Clipperton Zone (CCZ), where there are several orders of magnitude less life than on land. This is one of the least populated areas on the planet (300–1,500 less biomass than on land)—effectively an underwater desert with no plants, no light, high pressure, and few sources of food. Seventy percent of its low resident biomass is made up of microbial organisms, with the remaining biomass composed of a small population of deep-sea worms, sponges, and fish.
The abyssal plain is the most common environment on the planet, covering more than 60% of the planet’s surface, and is completely unlike the unique island ecosystems mining on land threatens. The risk of species extinction and biodiversity loss will be reduced by setting aside large areas of the abyssal plain for conservation; the ISA has already set aside more area under protection in the CCZ than is currently under exploration.
As part of our ongoing Environmental and Social Impact Assessment (ESIA) program, we are studying species all throughout the overlying water column and above water surface to make sure we understand how these ecosystems interact and function. This uniquely comprehensive approach goes beyond land-based impact studies, and includes understanding microbial populations and worms living in the seafloor mud. This will help us make better decisions about how to further mitigate our impacts, what additional areas to set aside, how to design our collector robots, where to return seawater used to lift nodules from the seafloor, and what indicators to monitor during operations to keep within expected thresholds and reduce our impacts.
Ultimately, sourcing battery metals from loose-lying polymetallic rocks in the CCZ puts us in a better position to reduce the risk of species extinction than intensifying land-based extraction for these same metals in highly-biodiverse terrestrial ecosystems.
Each nodule operation would effectively strip mine vast areas of the seafloor over several decades.
This claim is misleading with regards to both process and scale. Strip mining is the removal of vegetation, soil, and rock (“overburden”) above a layer or seam of minerals, followed by the removal of the exposed mineral. During this process, the entire surface ecosystem is removed before excavation is used for softer rocks, and drilling and blasting is used to break up and remove the sub-surface hard rock.
Collecting polymetallic nodules is different. Nodules are loose rocks sitting exposed on top of seafloor sediment, with 95% of nodule mass contained in the top 5 centimeters. There is no overburden to remove. As nodule collectors move along the seafloor, they direct jets of seawater across the nodules to lift and collect them inside the machine, using the Coandă effect. While up to 5 centimeters of soft mud under the nodules will travel inside, it will be separated and redeposited back at the seafloor. This process is engineered to minimize impact on the marine environment and involves no strip mining, drilling, or blasting of the seafloor.
It’s also worth noting that nodule collection is projected to impact 40,000 km2 of the abyssal seafloor per year for 30 years. This is less than 1% of the estimated 4,900,000 km2 of the seafloor impacted every year by trawling.
Sediment plumes from nodule collection could travel far from the mining sites and smother sea life.
Recent in-situ experiments and studies show that the vast majority of sediment kicked up during operations will settle quickly, mostly within 4 kilometers and within a few days, and dilute to natural background concentration levels—the most relevant metric for sea-life impact—within 1 kilometer. Our own research in this area is currently in progress, and our engineering partners are focused on optimizing our collector and riser system to further reduce our impacts.
Anti-deep-sea-mining campaigners emphasize the long distances over which the finest sediment particles (less than 5% of suspended mass) from nodule collection could travel before re-settling onto the seafloor. This emphasis has led to considerable speculation about extensive and widespread impacts of deep-sea-mining activities. However, these speculations are not grounded in science. Evaluating the impact of sediment plumes on abyssal wildlife requires assessing the area’s natural background concentration of sediment. A recent study in the abyssal plain showed that plumes reduce to natural background sediment concentrations similar to an area’s average concentrations, after 1 kilometer.
Discharge of the tailings from dewatering ore will introduce sediment and dissolved metals over potentially large areas.
Sediment should not be confused with tailings. Tailings are the materials left over after the process of separating the valuable fraction from the uneconomic fraction of an ore. Tailings are distinct from overburden, which is the waste rock or other material that overlies an ore or mineral body and is displaced during mining without being processed (i.e., chemically). Small amounts of residual sediment and abraded nodules found in the seawater used for nodule transport are more analogous to the removal and redeposition of overburden during a terrestrial mining operation.
Experimental work conducted by MIT (PlumeX, in peer-review) and plume modelling performed by DHI as part of DeepGreen’s ESIA program show extremely high dilution of sediment concentration within moments of discharge. It’s worth noting that chemical markers were necessary to trace these particles in the water column, as traditional methods failed to register the plumes’ rapid dilution. If we make the unlikely assumption that all discharged particles will stay suspended in the water column, more than 20 concurrent nodule operations would be required for particle concentrations to rise above normal, background levels in the CCZ. If, on the other hand, we make another unlikely assumption that all particles introduced in the water column by these operations rapidly sink to the seafloor, the resulting fallout would be 0.02 micrograms per year—just 2% of the observed normal sedimentation rate in the CCZ.
Nodules are friable, and turbulence will cause some fragmentation during their rise to a collection ship, where screens and centrifuges will retain particles larger than 10 microns, with smaller particles entering the return flow. Metals in those particles are all present as compounds, which may have less toxicity than in free ion form. The impacts of metals leaching from nodules are not fully understood but are being considered as part of our ongoing Environmental and Social Impact Assessment.
A single nodule collection operation would discharge 50,000 cubic meters of sediment, broken mineral fines, and seawater per day, and could run for 30 years, releasing 500,000,000 cubic meters over its lifetime.
Nodule collection displaces very soft clay that lies beneath each rock. With no overburden, this waste stream differs from terrestrial waste, as it’s composed almost entirely of seawater.
The first nodule-collection waste stream is made up of displaced sediment (13.8kg per square meter) redeposited on the seafloor. The second comprises a small portion (around 8%) of remaining sediment, which enters the riser, is combined there with a mass of nodule fines and then returned to below 1,200 meters, at a depth scientifically chosen to have minimal impact.
It’s also worth noting that both the mining phase on land and the nodule-collection phase in the deep sea tell only half the story. On land, nickel sulfide, copper ore, and cobalt concentration produce large waste flows. As ore grades decline further, concentration waste will increase. While waste generated from nodule processing is dependent on methodology and flowsheet, high ore grades and nodules’ lack of toxicity enable zero-solid-waste processing. When sourcing metals for 1 billion EVs, nodules would generate no solid processing waste and no toxic tailings.
Surface support vessels, seafloor equipment, and riser pipes will create noise pollution.
Nodule collection will generate some noise, and our research team is currently collecting background noise levels in order to study potential impacts of operating in the CCZ. However, our operation will not use sonar and is not expected to make dangerously loud noises, such as those produced by blasting during land mining. Most noise will be highly localized and similar to that of typical ship operations. Noise levels are unlikely to exceed the gross impact of military and commercial operations, which are far more widespread across the oceans, and which all use sonar.
While whales may migrate through our contract areas in the CCZ, these areas are unlikely to be a feeding or breeding site for large marine mammals given the low productivity of their surface waters. Nodule collection operations will likely be audible to various marine organisms and could interfere with communication or other processes over limited distances. At the same time, this noise may also prove useful in alerting them to our presence and avoiding contact.
The acoustic effects of nodule collection are being investigated as part of our ESIA. This data will also be used to inform engineering and design decisions to reduce noise wherever possible.
Deep-sea mining will destroy marine genetic resources that could provide new medicines and breakthrough treatments.
We believe the opposite is true: Our exploration activities can be a primary driver of research and discovery when it comes to marine genetic resources. The Metals Company has already compiled an extensive library containing over 20,000 preserved biological samples collected at 7-kilometer intervals. Sample collection and preservation is an integral part of our exploration program and we expect to collect many more samples as we explore new parts of our contract areas. We are actively seeking academic partnerships to understand the genetic resource potential of this ever-expanding library.
In addition, a larger area in the CCZ has already been set aside for conservation than is currently under exploration. These protected areas will remain protected from any future nodule collection operations and will be available for continued research on marine genetic resources, new genes, antibiotics, and pharmaceuticals.
Deep-sea ecosystems will never recover from deep-sea mining.
This is untrue. Our collectors would only remove most nodule cover around the top 5 centimeters of sediment. Recovery can start naturally and immediately after the collector moves on.
Between the 1970s and present, scientists have conducted 11 seafloor disturbance and commercial mining studies. They repeatedly revisited these sites over a 26-year time period to measure each area’s recovery. Review studies of research to date show that mobile and pelagic fauna density and diversity recovers within one year, and microbial density, diversity, and function (70-80% of the total biomass impacted by nodule operations) are expected to recover within 50 years. New nodules will continue forming on the impacted site, but it will take up to 5 million years to regenerate nodule cover comparable to pre-disturbance state. Recovery of species that need the hard substrate of nodules (<10% of the total biomass impacted) is currently not known and depends on habitat connectivity, recruitment, and the extent of remaining nodule coverage.
Compare this rate of recovery to the default driving nickel supply growth today: mining nickel laterites in Indonesia. The entire overlying rainforest ecosystem is removed (trees, plants, soil, rock, and all animals and microbes living therein). As the rainforest is cleared, the organic carbon it contains is released, and the below-ground microbial and worm populations die. Recovery can only start when mine operations cease in the area (this can take many years) and requires active restoration efforts and funding by the mine operator or local government.
We don’t know how long it will take for ecosystems to regenerate, but we know that it takes hundreds or thousands of years to regenerate new soil and forests that can support previous levels of biodiversity. Removed nickel laterites can reform through continued weathering and wet leaching of unweathered rock but—like nodules—will take millions of years.
It’s important to understand that when organizations advocate for a moratorium on deep-sea mining, they by default, accept significantly increased deforestation, mine waste and toxic tailings, and the destruction of terrestrial habitats and carbon sinks in order to build the batteries the world needs for a transition to clean energy.