Do we need to tackle climate change? Yes, and fast! Do we need to mine the deep sea in order to do so? Definitely not.
Deep-Sea Mining Is a Violation of International Law
The deep sea belongs to each and every one of us. The United Nations Convention on the Law of the Sea defined the international seabed as “common heritage of humankind” – a revolutionary principle of international law that aims for the heritage to be held in trust for future generations and protected from exploitation by individual nation-states or corporations. The deep seabed is also called “The Area” and includes the seabed, ocean floor and subsoil in areas outside of countries’ continental shelf. Responsible for the protection of this unique heritage of humankind is the International Seabed Authority (ISA) established in 1982 by UNCLOS. As of today, no mining operations are allowed by the ISA. Furthermore, more and more countries (33 as of now) are pushing towards further protection of the deep sea by forming the deep-sea conservation coalition and signing a deep-sea mining moratorium, which should delay a decision about mining activities for another 20 years. Germany signed the moratorium in 2022, Switzerland in 2023.
What Has Trump Done on 24 April?
On 24 April 2025, US President Trump signed an Executive Order to start deep-sea mining in the Pacific Ocean. Why has he done that? Because the Metals Company (TMC) – currently the company most eager to start mining polymetallic nodules from the seabed – is working with the Trump administration to gain authorisation to mine in international waters. Are they allowed to do that? No! Deep-sea mining is regulated by the ISA or rather – should be regulated by the ISA. At the moment of writing, no Mining Code (the main regulatory document) has been agreed upon. This should provide a regulatory framework for the exploitation of the resources in “The Area” including measures to protect the marine environment and wildlife in the deep. Part of the UNCLOS agreement was that, as soon as one country stated they wanted to start mining in the deep sea, a so-called “two-year rule” was triggered, giving the ISA a period of two years to consider and provisionally approve the application to mine – essentially, writing, agreeing upon, and approving the Mining Code, that states the framework under which mining can be allowed.
This rule was triggered by Nauru in 2021 – a Pacific island nation in co-operation with TMC. The ISA has not managed to agree on how to mine the seabed – rather the opposite. More and more countries have stressed the risk and lack of knowledge about the pristine and ancient ecosystems. TMC got impatient and with the US (one of the only countries that did not sign UNCLOS) currently governed by president Trump, TMC saw an opportunity. Using the old strategy “if mum says ‘no’, you go ask dad”, TMC stopped waiting for international approval and just asked the biggest fish in the pool and the one most likely to say “yes”. And as expected, the Trump administration agreed to speed up “the process for reviewing and issuing seabed mineral exploration licenses and commercial recovery permits in areas beyond national jurisdiction” (White House).
How Is Switzerland Involved
Mining the deep sea is a huge investment and TMC requires funds from the biggest companies in the industry. The Allseas Group has its head office in Châtel-Saint-Denis in the canton of Fribourg and owns 20% of TMC making it the biggest single shareholder. Glencore, another Swiss giant, with its headquarters in Baar in the canton of Zug, was one of the first companies to invest in TMC and has TMC’s guarantee to buy 50% of the extracted minerals from the deep sea.
Another company involved in the business is the originally US-American company Transocean, which now has their headquarters in Steinhausen in canton Zug. You might know this company as the operator of “Deepwater Horizon”, which is responsible for the gigantic oil spill in the Gulf of Mexico in 2010. Transocean holds shares in Global Sea Mineral Resources (GSR) a company that, like TMC, aims to extract minerals from the deep sea.
But let us take a step back here. The whole framework of the ISA, the attitude of President Trump and the investments of these Swiss companies assume that mining will be done anyway and the only question to consider is how to mine the deep sea and when to start. But deep-sea mining is the environmental exploitation of the common heritage of humankind for the benefit of private companies, and we do not need it as humanity.
Why Do Mining Companies Want to Mine the Deep Sea?
At the bottom of the ocean we can find a range of different metals. Some are contained in the oceanic crust, others are at seafloor vents. But of highest interest for mining companies are polymetallic nodules. They are found in different regions of the world at the ocean floor, not attached to the bottom and are roughly two to eight centimetres in diameter. The nodules contain nickel, cobalt, copper and manganese as well as rare earth elements. The argument made by mining companies, that we need these for the energy transition, is false. For copper and nickel, we can ramp up recycling (currently roughly 30% of supply is from recycling), nickel and cobalt are replaceable (half of EV batteries in 2023 did not contain any nickel or cobalt) and manganese is not even a critical metal because it is so abundant (see section below).
On 5 May, TMC proudly announced that they submitted their application for Commercial Recovery of Deep-Sea Minerals in the High Seas under US Seabed Mining Code, meaning they are aiming to mine the deep sea – common heritage of humankind – which the international community largely agrees not to mine (signed moratorium) by just asking the biggest fish in the pool. The problem with international law: the US did not sign UNCLOS (the United Nations Convention on the Law of the Sea) but that does not mean that they are allowed to exploit something that belongs to all of us. The Metals Company and the US will be the only ones benefitting from our shared heritage, the Swiss companies Glencore and Allseas are helping them commit this crime even though Switzerland signed the moratorium to protect the deep sea. Now it is our time to protect what belongs to us because no one else will.
Resources for the Energy Transition?
TMC claims that we need “deep-sea mining for a green future”. We need to reduce our emissions because climate change is a major threat to society in terms of natural disasters, heatwaves, and water shortage. It is therefore crucial that we take measures to prevent the unmanageable and manage the unpreventable. But, taking a conservative approach to solving the problem, we also want to sustain economic growth that makes our shrinking and ageing population more and more wealthy. In order to achieve both goals we need our economy to shift to renewable energy sources, which requires a massive build-up in solar, wind and hydro power as well as a shift towards renewable means of transportation, and a carbon-neutral chemical and heavy industry. This massive transition needs mineral resources. In total, we need less resources than if we continued to use fossil fuels, but we need partly different resources than what we mined so far. This causes a shift in the geographical focus of resource extraction and in the geopolitical power attached to it. Let us look at the metals that could be extracted from the ocean floor.
Cobalt
Cobalt is mostly used in batteries (70%) including EV batteries (45%) and portable batteries (26%). Other use cases are superalloys and ceramics. Cobalt is mostly mined as a byproduct of copper and nickel mining with 60% of global production coming from the Democratic Republic of Congo. Copper mines in DRC are known for horrible working conditions, child labour and human rights abuses, which is why the push towards innovation in alternative EV batteries away from cobalt has shown success. In 2021, IRENA still projected that demand for cobalt could triple in order to reach the 1,5 °C goal. However, half of the passenger EVs sold in 2023 already did not contain any cobalt.
Nickel
Currently, 65% of Nickel is used for production of stainless steel, 10–15% is used for batteries and 10% is used for superalloys. Nickel is not only used in much larger quantities than cobalt (total supply around 3.8 Mt in the year 2023 compared to 0.22 Mt for Cobalt) but it is also way more established with currently about one-third of global nickel supply coming from recycling. The single largest nickel producer in 2025 was Indonesia. As with cobalt, innovation has shifted away from the use of nickel in batteries for EVs with half of the EVs sold in 2023 not containing any nickel. Demand for nickel will most probably still increase. But the paradigm that we need nickel for the green transition does not hold. TMC uses the argument that nickel extraction in Indonesia harms the Indonesian rainforest and therefore, we should shift to mining subsea (TMC). Seeing that recycling is possible and well-established, should we not rather invest more into reaching 100% of nickel supply from recycling?
Copper
Copper is essential for the energy transition. It is used in grid wiring, Solar PV and wind turbines. Roughly 44% of global copper is used for power generation, distribution and transmission, with another 14% used for appliances and electronics. Copper also has other uses (20%) like construction and transport (12%). Like Nickel, it is well-established – the third most-used industrial metal in the world. Copper is also one of the few materials that can be recycled repeatedly without any low of performance and with less CO2 emissions than mining it. Depending on the region only 30–40% of copper stems from recycling. Copper also has many different land reserves, mainly in Chile, Peru and the African Copper Belt mainly in the Democratic Republic of Congo. These regions all have their usual stories of environmental impact, polluted waste water, impact on indigenous communities and human rights violations attached, but compared to the deep sea, there are people around observing the activities, reporting and fighting against pollution. To put it with the words of IRENA: “We will not run out of copper any time soon”.
Manganese
Manganese is not a critical metal. It is mainly used in steel production (90%), mined in South Africa, Australia and China. Our current reserves (resources where extraction would be economically viable) are 30 times our annual demand and the resources (how much we know there is still in the ground at the moment) is 660 times our annual demand.
So deep-sea mining is not only harmful, but it is also not needed for our shared clean future.
