Deep-sea mining gets a second look

BOSTON — The risk of running out of rare earth metals that are essential to modern technology has led to a surge in interest in mining the deep seas.

Demographic growth and the acceleration of technological innovations in the past 40 years have doubled the quantity of minerals extracted worldwide, leading to shortages of certain key metals, according to a recent United Nations report.

“Mining is essential for modern life,” said Professor Emeritus of Industrial Ecology Thomas Graedel of Yale University. “If global development proceeds at its current pace, traditional land-based supply of resources may be challenged to meet demand.”

When it comes to copper, an essential element for electrical equipment and numerous industries, a shortage could begin about 2050, he said.

This uncertainty highlights the importance of considering deep-sea mining, even though the process involves environmental risks. Cobalt, iron, manganese, platinum, nickel, gold, and other rare minerals are usually found at depths ranging from a few hundred to several thousand metres.

But just how much valuable material lies beneath the ocean floor remains highly uncertain, said Professor Mark Hannington, a geologist at Geomar-Helmholtz Centre for Ocean Research in Germany.

Observations so far indicate that sea floor deposits targeted for mining could include from 545 million to 907 million tonnes of minerals, including 27 million tonnes of copper and zinc, resources that could help respond to global demand for electronics.

He also said that nodules — or rocky formations containing valuable metals on the ocean floor — “are enormously abundant”.

But details on this potential remain poorly understood because, for the past three decades, exploration has been concentrated on certain areas near hydrothermal vents.

“We have not found the large deposits yet,” said Prof Hannington. “We have to figure out how to find them if we want to truly understand the resources. We’ve got to speed up the process dramatically because it has taken 30 years to get to where we are now, and 30 years from now, it will be too late.”

He added that all the zones granted exploration permits so far represent only 0.5 per cent of the total area that could be mined in the ocean.

Until now, 27 countries, including India and China, have signed contracts to search for these resources with the International Seabed Authority. AFP