Metal Stocks in Society report
The report Metal Stocks in Society: Scientific Synthesis was the first of six scientific assessments on global metals to be published by the International Resource Panel
International Resource Panel
The International Resource Panel is a scientific panel of experts that aims to help nations use natural resources sustainably without compromising economic growth and human needs...

 (IRP) of the United Nations Environment Programme
United Nations Environment Programme
The United Nations Environment Programme coordinates United Nations environmental activities, assisting developing countries in implementing environmentally sound policies and practices. It was founded as a result of the United Nations Conference on the Human Environment in June 1972 and has its...

. The IRP provides independent scientific assessments and expert advice on a variety of areas, including:
  • the volume of selected raw material
    Raw material
    A raw material or feedstock is the basic material from which a product is manufactured or made, frequently used with an extended meaning. For example, the term is used to denote material that came from nature and is in an unprocessed or minimally processed state. Latex, iron ore, logs, and crude...

     reserves and how efficiently these resources are being used
  • the lifecycle-long environmental impacts of products and services created and consumed around the globe
  • options to meet human and economic needs with fewer or cleaner resources.

About the report

Metals were an early priority for the International Resource Panel
International Resource Panel
The International Resource Panel is a scientific panel of experts that aims to help nations use natural resources sustainably without compromising economic growth and human needs...

, since little was known about them, their impacts, their economic importance or their scarcity. The report aimed to calculate the amount of metals present in society and assess the potential for utilising in-use stock to offset demand from virgin metal. Knowing how much metal stock there is in use, and how long the lifespan of the metal is, can help planners know when these metal stocks will enter recycling or waste streams. It suggested that these 'mines above ground' had growing potential for future metals supply; the authors found that there is about 50kg of above-ground copper for every person on earth, and more than two tons of iron per capita. However, they noted that enormous disparities in global metals stocks existed between developed and developing nations including Brazil, China and India.

Calculating ‘anthropogenic stocks’ of metals already in use in society is a pre-cursor to stimulating efforts to increase recycling. The authors reported that very little information is presently known about different metals, making it difficult for policy makers to develop and plan recycling systems. However, what is known is that recycling can not only reduce negative impacts on the environment but also save energy. For example, 95% of the energy used to make aluminium from bauxite ore is saved by using recycled material.

The authors quantified per capita stocks of the following metals, for some countries (stocks were mostly quantified for developed countries but data was also available for some developing nations).
  • Major engineering metals: Aluminum, Copper, Iron, Lead, Steel, Stainless steel, Zinc
  • Precious metals: Gold, Palladium, Platinum, Rhodium, Silver
  • Specialty metals: Antimony, Cadmium, Chromium, Cobalt, Magnesium, Manganese, Mercury, Molybdenum, Nickel, Tin, Titanium, Tungsten

The table below shows extant in-use metal-stock estimations for the major engineering metals:
Metal Number of estimates Percentage of all estimates Global per capita stock MDC per capita stock LDC per capita stock
Aluminium 9 7.4 80 350–500 35
Copper 34 27.0 35–55 140–300 30–40
Iron 13 10.7 2200 7000–14000 2000
Lead 20 16.4 8 20–150 1–4
Steel 0.8 7085
Stainless steel 5 4.1 80–180 15
Zinc 14 11.5 n/a 80–200 20–40

Why we need to recycle not mine

Some primary stocks of rare but useful metals are already running low. For example, Rhenium
Rhenium is a chemical element with the symbol Re and atomic number 75. It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an average concentration of 1 part per billion , rhenium is one of the rarest elements in the Earth's crust. The free element has...

(Re) only occurs at seven parts per billion in the Earth’s crust, making it one of the rarest elements on the planet. However, its high melting point of 3,186°C makes it valuable in the manufacture of jet engines. Demand for the metal is rising, with increasing air travel, but its rarity means increasing extraction is not simple. This is where recycling comes in; rhenium is one of the few metals that has witnessed a rise in recycling rates. It is likely that recycling will become a more viable option than extraction for other metals in future, saving energy, cutting greenhouse gases emitted to the atmosphere and reducing negative impacts on the environment.

External links

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