Sustainability can be defined as future viability. The natural environment supports all social and economic activity, so the benefits of natural resources need to be shared across all of society and the use of material resources needs to be managed in a way that they can be maintained over a long period of time, rather than being continuously depleted. The environment, social and economic dimensions of sustainability must all be met to ensure future viability.
Sustainability for the environment is met when the rate of consumption of natural resources does not exceed nature’s rate of replenishment. As well, the rate of pollution generated by economic activity cannot exceed nature’s rate of restoration.
Social sustainability is met when society provides for all the basic needs of humanity. Healthy communities ensure the rights and culture of all members are respected and protected
When secure sources of livelihood are available to everyone then economic sustainability has been attained. Independent communities have access to the human and material resources required to meet their needs.
Unfortunately no industrial materials, from commodity crops, cement, forest products, metals or plastics are fully sustainable at this time. For metals, environmental sustainability will be achieved when all new production is air, water and land neutral and completely sourced from recycled raw materials. All metals are completely recyclable, however recycling rates are still not sufficient to meet new metal demand and existing production processes have a very heavy environmental footprint for air, water and land. Sourcing end-of-life materials is the primary challenge. The recycling supply chain is improving, although many processing challenges still exist. Many products are made from a combination of metals, which can make recovery of individual metal values difficult. Some metal in products will also be lost in use to corrosion and wear, so that the full quantity of metal from the product can never be recovered. Despite these challenges the industry is working to increase recycling rates for all metals.