Mining for green metal in the deep blue sea

The prospect of humanity mining for metals on the deep seabed has been prophesised for decades. No longer would we have to tear up the earth with diggers and explosives, clearing mountains and forests - and their inhabitants, be they mammal, amphibian or otherwise - to get the iron, copper and other minerals from which modern society is built. We would merely sweep up metal-rich Pelagites - potato sized rocks more commonly called nodules - from seabeds far offshore.

Pelagite (deep sea nodule) of manganese (Wikipedia Commons CC BY 2.0, James St. John)

The technology required to do this at commercial scale has long frustrated efforts to attempt extraction on seabeds that could easily be a kilometre below. We are now close to being able, thanks to advances in robotics and the adaptation of high-tech umbilical pipes used in deep-sea oil and natural gas production.

Legislatures have started to take notice. The United Kingdom's Parliament was unusually early in this regards, passing the Deep Sea Mining Act 2014. Passed via the relatively rare - and rarely succesful - legislative Private Members Bill route, it seeks to ensure that deep sea mining in British waters (including, crucially, the water surrounding Overseas Territories such as British Antarctic Territory) is regulated, to ensure environmental protection.

Norway is being more pragmatic, and is to allow deep sea mining in its waters, joining a club that includes Russia, India and China. It will, however, maintain the right to prevent licences being issued if it believes that the practice would cause disproportionate environmental damage, though this has yet to be tested.

Unsurprisingly, deep sea mining is highly controversial, with many environmentalists up in arms. After all, whilst we know that life exists in the far depths of our oceans, these have been less explored than the Moon and Mars.

As this article from The Economist suggests, it gets complicated. The closing communiqué of COP28 voiced that the world needs to at least triple the installed capacity of clean energy generation by 2030. This, plus the commensurate expansion of power transmission and storage, clearly requires huge amounts of metals such as copper, nickel, manganese and cobalt. The transition to renewable energy will require 6.5bn tonnes of metals by 2050.

The current main producer of nickel, for example, is Indonesia, which has hugely expanded its mining operations in the last few years, and with its huge reserves will do so further to satisfy demand. This will further accelerate clearance of some of the world's most abundant rainforests.

Norway, possessor of one of the world's largest sovereign wealth funds, and one exclusively funded by fossil fuel extraction, is once again a major target for environmentalists, who level that it's hypocritical. It is a huge supporter of electric cars (see my related blog post), which are chock-full of 'green' metals such as copper, nickel, aluminium and cobalt, and contends that clearing forests that act as huge carbon sinks and habitats for endangered creatures is a more destructive alternative (see this FT article: How big a hypocrite is Norway on energy matters?). 

The Economist gives another angle. To be economically viable, ores from mines on land need to be processed near to the mines. The process is hugely power intensive. For countries such as Indonesia that means relying upon the local coal-powered electricity grids. The vessels bearing seabed nodules, however, could potentially, depending on their intended market, choose to dock where cheap renewables power is abundant and therefore cheap (e.g. Norway, Sweden, Iceland).

As with many other facets of our current energy transition, there are no easy answers and we face compromises. We need to be careful how much metal we directly consume and indirectly drive being consumed. And when we have no other choice, we need those that supply us to robustly analyse the full lifecycle costs of how they source green metals.

The answer may, or may not, lie on the bottom of the deep blue sea.