This article is based on a recent peer reviewed article, Metal mining on land versus the ocean in the context of the current Biodiversity Crisis, by V. Tunnicliff et.al. published on 5th March 2025 in the NPJ Ocean Sustainability Journal.

It is commonly accepted by the world’s scientists that the world is going through a double crisis at the moment, climate change and biodiversity loss. As the world grapples with these issues, a new frontier has emerged: the deep seabed. This vast, largely unexplored realm holds valuable metals, like nickel and cobalt, used in batteries for electric vehicles, in an attempt to reduce greenhouse gas emissions from fossil fuels and combat climate change.

These metals are also in demand for other less noble reasons such as military weapons. However, tapping into these resources poses a significant threat to marine ecosystems and actually has the potential to speed up climate change by damaging the health of the world’s largest carbon sink, the ocean. The impacts of the mining process on species that rely on the seabed and surrounding water column also clash with global efforts to protect biodiversity.

The demand for these metals is rising, with some projections indicating potential shortages within the next 10-15 years. This has spurred interest in deep-sea mining, with proponents arguing it’s a more “sustainable” alternative to land-based mining. However, a closer look reveals that this may not be the case.

Land based mining has had a controversial history.While land-based reserves of metals like nickel may be enough to meet demand for the next 100 years at current mining rates, the industry faces significant challenges. Mining often leads to ecological damage and habitat loss, particularly in countries with rich biodiversity. The Democratic Republic of Congo (DRC), a major source of cobalt, is plagued by social and environmental issues related to mining.

Despite these issues, the focus should be on improving land-based mining practices rather than simply transferring effort to the ocean, where it is unseen and so cannot be scrutinised. There is also no reason to think that seabed mining will have any effect in reducing land-based mining, apart from perhaps driving down the commodity price and causing even more hardship to small-scale miners in developing countries. What is needed are stricter regulations, better biodiversity protection and increased accountability for mining companies.

Meanwhile, deep seabed mining is a very risky activity to even be considering, given how little is known about the consequences. The International Seabed Authority (ISA) is currently developing regulations for mining the deep seabed, but because of the significant environmental issues to be considered, it is taking a long time to reach an agreement on what these may look like. The lack of scientific understanding about deep-sea ecosystems makes it difficult to assess the potential damage.

Key issues include:

• Unknown impacts: We know very little about deep-sea biodiversity and the consequences of disrupting these fragile ecosystems. Some species may be wiped out even before they have been discovered.
• Habitat loss: Deep-sea mining could result in widespread habitat destruction, far exceeding the impact of current land-based mining. Sediment plumes could drift very large distances, impacting areas well away from the mining site.
• Mitigation challenges: Restoring damaged deep-sea ecosystems is virtually impossible, and effective strategies to minimise damage are lacking.
• Monitoring difficulties: Monitoring mining operations in the deep sea is extremely challenging, making it difficult to detect and respond to environmental harm.

To be very clear, this is not a choice between two evils of land mining and seabed mining.Opening the deep-seabed to mining will not solve the problems associated with land-based mining. Instead, it will add another layer of environmental degradation. The idea that deep-sea mining is a more “sustainable” option is misleading.

The focus must shift to improving land-based mining practices. This includes:

• Stronger regulations: Implementing stricter, internationally agreed-upon standards for environmental management.
• Improved oversight: Ensuring rigorous monitoring and enforcement of regulations.
• Investing in research: Conducting research to better understand and mitigate the impacts of mining on land.
• Promoting recycling and alternative technologies: Alternative battery technology is already available, reducing the need for the metals found on the deep seabed. Encouraging the development of these alternative technologies and increasing recycling efforts to reduce the demand for raw materials is a much more sustainable approach to reducing the use of fossil fuels.
• Responsible consumption: Educating consumers about the environmental costs of mining and promoting sustainable consumption patterns. Do we really need a new mobile phone every year?

Before considering deep-sea mining, a precautionary pause is essential. We need to prioritise research to fully understand the potential consequences. Simultaneously, we must work to improve land-based mining practices and regulations.

The history of terrestrial mining has shown us the devastating consequences of unchecked exploitation. We cannot afford to repeat these mistakes in the deep sea. By focusing on improving land-based mining and adopting more sustainable practices, we can protect biodiversity and ensure a more sustainable future.