Figure of the month: 10 million tonnes

If the annual global output of gold of more than 3,000 tonnes, as was the standard in recent years, does not change drastically in the near future, minable gold deposits will be exploited in approximately 19 years. Does this mean that all gold deposits on this planet will then be exhausted? By no means: at least 10 million tonnes of gold still remain at the bottom of the world’s oceans, which cannot currently be mined since it is either technically impossible, not approved or simply too expensive to be financially attractive. This might change in the foreseeable future: China, the country with the largest production volumes and, at the same time, the largest demand for gold, a few years ago announced its intentions to start mining gold under the Indian and Pacific Oceans by 2030, at the latest. To this end, more than 80,000 square kilometres of seabed had been surveyed by 2012, and China is confident that the development of its deep-sea mining technologies will continue throughout the next 13 years to make the production of gold financially worthwhile by then.

However, the world's oceans offer much more: according to findings by the US weather and oceanography agency NOAA, the seawater itself holds at least 20 million tonnes of gold. The problem: on average, every litre of seawater contains only a few billionth grams of the precious metal. However, gold is not evenly distributed within the waters of the world’s oceans. For example, a team of scientists from Kiel, Germany, in cooperation with Icelandic researchers, discovered a high gold concentration below hot springs of the Reykjanes peninsula in the south-west of Iceland. It is estimated that at least 10,000 kilograms "swim" in this area. With the aid of special bacteria and a biotechnological process, scientists claim it will be possible to collect the gold nanoparticles in an environmentally friendly way and at reasonable costs. This could solve the future problem of gold shortage for a long time to come.