A recent paper published in the journal Trends in Ecology and Evolution estimates that humans are heading for a situation in which 80% of the elements we use are from non-biological sources.

Written by researchers at the Ecological and Forestry Applications Research Centre, the Universitat Autònoma de Barcelona (UAB) and the Spanish National Research Council (CSIC), the article notes that in 1900, approximately 80% of the elements humans used came from biomass (wood, plants, food, etc.). That figure had fallen to 32% by 2005 and is expected to stand at approximately 22% in 2050.

Non-biological elements, however, are scarce or practically absent in living organisms, and rare in general; in many cases, their main reserves are located in just a handful of countries.

These elements must be obtained from geological sources, which entails extraction, trade between countries, and the development of efficient recycling technologies, while their scarcity and location create the potential for social, economic, geopolitical and environmental conflicts.

Squeezing the periodic table

The study looks back at the history of humankind in relation to its use of the periodic table’s elements.

“Humans have gone from using common materials, such as clay, stone and lime, the elements of which are constantly recycled in the ground, in nature and in the atmosphere, to using lots of other elements, notably including those known as rare earth elements,” Jordi Sardans, CREAF researcher and co-author of the study, said in a media statement.

According to the article, the human elementome, which is a range of chemical elements humans need, and the biological elementome, which is the set of chemical elements that nature requires, started to diverge in the decade of the 1900s, a result of continuous growth of the use of non-biomass materials such as fossil fuels, metallic/industrial materials, and building materials.

Elements used in construction, transport, industry, and more recently, new technologies, such as computation and photovoltaic devices and mobile phones, were added to the human elementome over the course of the 20th century.

They include silicon, nickel, copper, chromium and gold, as well as others that are less common, such as samarium, ytterbium, yttrium and neodymium. In the past two decades, there has been an increase in the use of such scarce elements, owing to the implementation and expansion of new technologies and clean energy sources.

“Mineral element consumption/extraction is rising at a rate of around 3% a year, and that will continue up to 2050,” Josep Peñuelas, the other co-author of the study, said. “In that scenario, it is possible that we will have used up all our reserves of some of those elements (gold and antimony) by 2050, and of others (molybdenum and zinc) within a hundred years.”

Risks and opportunities

According to Peñuelas and his colleagues, the extraction of earth’s chemical elements could be a limiting factor and lead to crises at every level.

Using more of the periodic table’s elements involves the extraction of more minerals, rising energy consumption and the associated CO2 emissions. Furthermore, the growing scarcity of the elements in question is a threat to their availability, especially where poorer countries are concerned, and makes maintaining production difficult even for wealthy countries, thus affecting economic development.

Against this backdrop, there are also important and problematic geopolitical considerations.

The natural reserves of some elements, including rare earth elements, are located in a limited number of countries (China, Vietnam, Brazil, the US, Russia and the Democratic Republic of the Congo); China actually controls over 90% of the global supply and close to 40% of reserves. Their availability is therefore subject to fluctuations in supply and prices caused by opposing geopolitical interests, with the consequent danger of conflicts.

The authors stress the need to put an end to programmed obsolescence, which is the policy of planning or designing a product to have an artificially limited useful life, as well as to develop new technologies that contribute to more profitable use of scarce elements and allow for their widespread, efficient recycling and reuse.

Source: MINING.COM – Read More