The integrated systems dynamics model WORLD6 was used to assess long-term supply of stainless steel to society with consideration of the available extractable amount of raw materials. This was done handling four metals simultaneously (iron, chromium, manganese, nickel). We assessed amounts of stainless steel that can be produced in response to demand and for how long, considering the supply of the alloying metals manganese, chromium and nickel. The extractable amounts of nickel are modest, and this puts a limit on how much stainless steel of different qualities can be produced. The simulations indicate that nickel is the key element for stainless steel production, and the issue of scarcity or not depends on how well the nickel supply and recycling systems are managed. The study shows that there is a significant risk that the stainless steel production will reach its maximum capacity around 2055 and slowly decline after that. The model indicates that stainless steel of the type containing Mn–Cr–Ni will have a production peak in about 2040, and the production will decline after 2045 because of nickel supply limitations. Production rates of metals like cobalt, molybdenum, tantalum or vanadium are too small to be viable substitutes for the missing nickel. These metals are limiting on their own as important ingredients for super-alloys and specialty steels and other technological applications. With increased stainless steel price because of scarcity, we may expect recycling to go up and soften the decline somewhat. At recycling degrees above 80%, the supply of nickel, chromium and manganese will be sufficient for several centuries.

The global cement and concrete demand, production, supply, and the general global market price was modelled using the WORLD7 model for different future scenarios. The model was used to analyze some possible measures to reduce the climate impact of cement production. The main result from this study is that three factors may bring regulatory limitations to be imposed on cement production. The contribution of CO₂ to the atmosphere, the amount of iron used in construction and the use of energy in production are the main factors that may cause limitations. Cement accounts for about 8% of the global CO₂ emissions and energy use at present, and this fraction is projected by the simulations to continue to increase. To reduce CO₂ emissions from cement production, ending fossil fuel use for calcination, combined with a change towards using mortar as an alternative for making concrete should be considered. Our conclusion is that the long-term limitation for cement production is the availability of carbon-free energy, and the availability of iron for reinforcement bars. Eliminating the use of hydrocarbons for cement calcination may reduce the future the contribution from cement by 38%. Eliminating the use of hydrocarbons for calcination combined with substituting cement with mortar to 50%, the contribution to the future global average temperature increase is reduced by 62%. Eliminating the use of hydrocarbons for calcination combined with substituting cement with mortar to 90% is a reduction by 90% in the contribution from cement.

The sustainability of the helium production, supply and use was assessed using the WORLD7 integrated model. The use of helium is at present concluded to be unsustainable with respect to long-term supply security, because of lack of significant recycling. There is no risk for significant helium scarcity in the short term (before 2030), but in the long term, the scarcity risk is unavoidable under business as usual. The helium supply runs into limitations by 2090, under business as usual and supply declines after that. The study shows that the present helium recycling rate is far too low, causing helium to be squandered in one-way use and that is driving helium prices up. A scenario analysis with the WORLD7 model suggests that a sustained program for helium recycling and demand management, combined with political efforts to ban unnecessary use, will be able to significantly improve the long-term helium supply situation. The outputs show that such efforts may be sufficient for avoiding any scarcity under the demand assumptions taken.

The increasing need for indium in photovoltaic technologies is set to exceed available supply. Current estimates suggest only 25% of global solar cell demand for indium can be met, posing a significant challenge for the energy transition. Using the WORLD7 model, this study evaluated the sustainability of indium production and overall market supply. The model considers both mass balance and the dynamic interplay of supply–demand in determining indium prices. It is estimated that a total of 312,000 tons of indium can be extracted. However, the primary hindrance to supply is the availability of extraction opportunities and the necessary infrastructure. Unless we improve production capacity, indium may face shortages, hindering the advancement of pivotal technologies. A concern observed is the insufficient rate of indium recycling. Boosting this could greatly alleviate supply pressures. Projections indicate that indium production will reach its peak between 2025 and 2030, while the peak for photovoltaic solar panels due to indium shortages is anticipated around 2090, with an installed capacity of 1200 GW. Thus, the growth of photovoltaic capacity may lag behind actual demand. For a sustainable future, understanding the role of essential metals like indium is crucial. The European Environment Agency (EEA) introduced four “imaginaries” depicting visions of a sustainable Europe by 2050 (SE2050), each representing a unique future set within specific parameters. Currently, Europe is heavily dependent on imports for tech metals and has limited recycling capabilities, putting it at a disadvantage in a global context. To achieve sustainability, there is a need for improved infrastructure for extraction, recycling, and conservation of metals such as indium. These resources are crucial for realizing Europe’s 2050 sustainability objectives. Furthermore, understanding the role of these metals in wider overarching strategies is vital for envisioning a sustainable European Union by 2050, as depicted in the Imaginaries.