A new report suggests that subsea copper mining is more sustainable than doing it on land.

Nautilus Minerals’ new Earth Economics report included independent environmental and social benchmarking analysis for the company’s Solwara 1 seafloor copper-gold resource project.

The study says Solwara 1 “has the potential to significantly reduce social and environmental impacts commonly associated with large surface terrestrial copper mines”.

“Mining in the deep seabed (assuming the creation of sufficient biodiversity conservation sites) has fewer identified, quantified and monetized impacts than terrestrial mining,” the report stated.

“Producing one tonne of copper results in far less freshwater use, mineral waste, energy use, area of disturbance, and CO2 emissions in Solwara compared with terrestrial mines.”

The study compared Solwara 1 with terrestrial mines at Prominent Hill, Bingham Canyon, and the proposed Intag mine.

It said the “deep seabed at the Solwara 1 mine is an advantageous choice of mining site for a number of reasons [as] no people live at the proposed mine site, and there are no cultural or historical claims to the site”.

“The mine site itself is quite small, covering only 14 hectares of seabed; natural resources are less impacted by operations at this site as surface or groundwater freshwater resources will be not used or contaminated at Solwara 1.

“In addition, there is limited overburden covering mineralised material, resulting in very little waste rock material; finally, the proposed mine operation wastes will be dwarfed in comparison to the impacts of a nearby erupting underwater volcano.”

Underwater mining is set to take off in coming years, with groups like the International Seabed Authority issuing a range of seabed mining licences for the Government of India, the Germany Federal Institute for Geosciences and Natural Resources, the Russian Ministry of Natural Resources and Brazil's Companhia de Pesquisa de Recursos Minerias.

Even the UN has plans to allow larger-scale extraction of various metals from beneath the seafloor.