Deniz Koca

The global cobalt cycle in society was modelled using an integrated systems dynamics model, WORLD6, integrating several earlier system dynamics models developed by the authors. The COBALT sub-model was used to assess the long-term sufficiency of the available extractable cobalt and address the effect of different degrees of recycling on cobalt supply. The extraction of cobalt is mostly dependent on the extraction of copper, nickel and platinum group metals. The ultimately recoverable resources estimate was 32 million ton on land and 34 million ton on the ocean floors, a total of 66 million ton, significantly larger than earlier estimates. It is very uncertain how much of the cobalt, detected in ocean floor deposits, is extractable. The present use of cobalt by society is diverse and about half the total cobalt production to the market is in the form of metallic cobalt. The simulations show that cobalt extraction is predicted to reach a peak in the years 2025–2030 and that the supply will reach a peak level in 2040–2050. Three different global population scenarios were used (high, middle, low). We predict that the supply of cobalt will decline slowly with about 3–5% per year after 2050. The present use of cobalt in chemicals, colours, rechargeable batteries and super-alloys shows a low degree of recycling and the systemic losses are significant. After 2170, cobalt will have run out under business-as-usual scenario. The present business-as-usual cobalt use in society is not sustainable. Too much cobalt is lost if only market mechanisms are expected to improve recycling, and unnecessary cobalt is wasted if no policy actions are taken. Increased recycling and better conservation will be able to improve the supply situation, but this will need active policy participation beyond what market mechanisms can do alone. To conserve cobalt for coming generations, present policies must be changed within the next few decades. The sooner policies change, the better for future generations