Seafloor Mining for Rare Metals – A Brilliant Idea or Another Environmental Catastrophe

For the upcoming World Leaders Summit, more than a dozen world leaders from 55 nations gathered at the Port of Brest in France. One Ocean summitAn unprecedented international political meeting was held to address a wide range pressing maritime issues, including overfishing, plastic pollution, and piracy.

One problem – seafloor miners seemed to be the focus of attention. French President Emmanuel Macron tentatively supports the idea. He has identified seabed exploration for France as an investment priority, highlighting the potential to gain rare metals and a better understanding about marine ecosystems.

Many environmental groups are opposed to the idea, claiming it will harm sensitive marine life, including species that have yet to be discovered.

In a letter to Secretary of Energy Jennifer Granholm this week, Senator Lisa Murkowski addressed the issue of seafloor mines to Murkowski. She pointed out that the United States had not ratified the United Nations Convention on the Law of the Sea (UNCLOS) and therefore is not participating in negotiations on regulations for seabed mining.

It is obvious that critical metals, such as Co, Li, Te and Nd are essential to A low-carbon energy futureIf electric vehicles and renewable energy are to play a significant role.

It is also undisputed that we are. We are woefully short of supplyA supply of these metals is generally limited Social and environmental nightmare.

The Waste from Li, graphite, and high-purity SiProcessing has Whole villages were destroyedand ecosystems China, Indonesia, and Bolivia, among other countries. America continues to deal with the acid mine drainageAfter 120 years of mine work, they are still in use. Half of the Co supplies are derived from child labor practices, similar to blood diamonds.

This is important because many of those who support the energy revolution of nonfossil fuels, renewables, electric vehicles, efficiency, conservation and efficiency also care about the social issues many of these technologies include – corruption and extreme poverty as well as child labor.

This is not the image that people want to see at the shade-grown coffee shop, surfing the internet for free-range eggs with their iPhones.

New metal sources must consider their life-cycle carbon footprint, social justice and environmental pollution. Although everyone agrees that it is great to recycle what metals you have, we will still need a thousand times more critical metals than we have right now, even if our recycling rate is 100%.

Geologists have known for a long time that the ocean floor is full of metals. Cu, Ni, Ag. Au, PtEven diamonds. Manganese nodules can be a polymetallic rock. Concreteions that lie loosely on the sea floor or buried shallowly in the sediment.

These nodules are found in all oceans, including some lakes, and they are abundant on the seafloor. Abyssal plains of the deep ocean between 4,000 and 6,000 meters (13,000 and 20,000 ft). It is possible to easily extract the nodules from the seafloor bottom.

The Clarion-Clipperton Zone, which is roughly the same size as Europe and stretches from the west coast to Hawaii, is the largest of all the economic zones. This area is also prominently featured at the One Ocean Summit this week. The total mass of manganese nodules in this zone is over 21 billion tons. Other areas of importance include the Peru Basin and the Penrhyn Basin close to the Cook Islands.

These areas are monitored by the United Nations International Seabed Authority (ISA).

These seabed nodules have a higher metal yield than metal ores on the ground, which are less than 20% and often less that 2% respectively. 99% usable minerals33% of the metal is useful for products like construction aggregate or fertilizer, as there are no toxic heavy elements such as mercury or arsenic.

So, there you go. There are no toxic tailings and mining wasteLike on land: no deforestation or open pits; no contaminated rivers and aquifers; no tailings impounded

Seabed mining does not employ child labor as much as land mining. Seabed mining has a 90% lower carbon footprint over land mining.

A Study by Paulikas et al. (2020) peer-reviewed studiesThe study compares ocean mining with land mining from a dozen environmental perspectives. The results show that ocean mining has a 70% to 99% lower impact on the environment than all other types of land mining.

This is what I love about it.

It’s not just habitat effects. The mining, pumping, cleaning and disposal of the manganese nudules can lead to some pretty significant effects. Vibrations, noise, and sediments.

The big question and the final decision is: Are the benefits in carbon, pollution, and social justice more important that the ecosystem damage to ocean floor? Can we reduce that ecosystem damage?

The Metals CompanyIt is evident that they do. Metals is a Canadian company that works in an ISA-granted section of the Clarion-Clipperton Zone. They have been undertaking a multiyear environmental impact assessment to understand the environment and to mitigate any potential harm. The area and the process are important in a few key aspects.

The Clarion Clipperton zone is one of the most productive areas of ocean. It has one of the lowest biomass environments in the world, much like deserts on earth. The Abyssal CCZ hosts 300 times less biomass than the average biome on land. It also has a 3000x lower level of biomass than the rainforest regions, where a lot more conventional mining is done. There are no plants. 70% of life is bacteria. Most organisms are less than 4cm.

I don’t want any organism to be trivialized, but Kurt Vonnegut said there is no free lunch. We must therefore mine the areas that have the least diversity and organisms as we will mine somewhere. Or, you can stick with fossil fuels.

Experiments were conducted to determine whether sediment was released into the water table. MIT, Scripps and The Metals CoThe sediment concentration per liter was diluted to an extremely high level within a matter of minutes after discharge. Experimental work has shown that 20 simultaneous operations would be needed to collect 3Mpta (wet), of nodules in order for particle concentrations above the background levels measured by the CCZ.

Additionally, if all particles introduced to the water column by these operations sink rapidly to the seafloor CCZ, the resulting fallout would only be 0.02 micrograms per annum, which is 2% less than the normal sedimentation rate in CCZ, which is 1 microgram per annum.

Based on 11 seafloor disturbance studies and commercial mining studies, ecological recover rates for nodule collection were much lower than those of mining on land decades versus milenia.

The ISA has protected more areas (1.44million km2) than are currently under exploration (1.1million km2). Contractors will add additional areas and leave behind 15% for recovery.

Research is being done to determine the best location to return the process waters. It appears to be at around 1,500 m, well below where there is likely to be any significant impact for organisms in the water column. Also, the temperature difference between the ocean floor and that water won’t cause any significant effects.

These processes are unlikely not to cause widespread deaths as many fear, including mine.

Seabed collectors, unlike land operations, will only disturb the top five cm of the seafloor. Instead, they will direct water parallel to the seafloor to lift the nodules, but not touch them.

This is not to suggest that the operation is perfect. However it will have much less impact than any land operations. It is the best way to get these critical metals between 2050 and 2050.

Hopefully, then we will be able to recycle enough that any mining that is required after that time will be minimal.