Advanced and transition scenarios

• Transition scenario. Assumes only changes in product design and reverse supply chain skills. Analyses in the two ‘Towards the Circular Economy’ reports typically assumed improvements in the underlying economics, with collection rates increasing by 20 to 30 percentage points, and a shift of approx. 30 percentage points from recycling to refurbishing or remanufacturing activities.
• Advanced scenario. Demonstrates potential repercussions in a world that has undergone more radical change and has further developed reverse technologies and infrastructure and other enabling conditions, such as customer acceptance, cross-chain and cross-sector collaboration, and legal frameworks. Analyses in the two ‘Toward the Circular Economy’ reports assumed collection rates increasing by 30 to 40 percentage points and an additional shift of 5 to 10 percentage points to refurbishing or remanufacturing.

Arbitrage opportunities. Opportunities to take advantage of a price difference between two or more scenarios. In the circular economy, an arbitrage opportunity entails the benefits in terms of material costs, labour, and energy that circular setups provide over linear models.

Bill of materials (BOM). A list of raw materials, sub-assemblies, intermediate assemblies, sub-components and parts, and the quantities of each needed to manufacture a specific end product.

Bio-based vs. biodegradable. Many bio-based products such as, for example, biopolymers are not necessarily safely biodegradable because they contain additives such as heavy metals or are combined with non-biodegradable materials. As well, petroleum-based products that are not bio-based can be biodegradable. Bio-based materials are derived from biological source, belonging to the biosphere. The definition of “biodegradable” includes that the material is shown to degrade completely in an industrial composting facility within a prescribed time frame. 

Cascading of components and materials. Putting materials and components into different uses after end-of-life across different value streams and extracting, over time, stored energy and material ‘coherence.’ Along the cascade, this material order declines (in other words, entropy increases).¹²⁹

Electrical and electronic equipment (EEE). Comprising both electrical equipment and electronic equipment. Electrical equipment includes any machine powered by electricity, such as major appliances and power tools. Electronic equipment encompasses equipment that involves the controlled conduction of electrons (using a semiconductor), allowing the amplification of weak signals for use in information processing, telecommunications, and signal processing, as for example in computers, mobile phones, television sets, refrigerators, and office equipment.

End-of use. Materials/products at the end of their primary use, that are collected and returned to the same usage, or cascaded to a new one.

Materials recycling 

• Functional recycling. A process of recovering materials for their original purpose or for other purposes, excluding energy recovery.
• Downcycling. A process of converting materials into new materials of lesser quality and reduced functionality.
• Upcycling. A process of converting materials into new materials of higher quality and increased functionality, also by improving on a down cycling process.

Plastics. Synthetic polymers consisting of thermoplastics, polymers that become pliable or mouldable above a specific temperature, and return to a solid state upon cooling. Alternatively, these may be thermoset plastics, which are polymers that irreversibly cure either via heat, chemicals, or radiation. Thermoplastics are more widely used (have the highest volumes), including the four most common polymers:

• Polyethylene (PE): High-density polyethylene (HDPE) is used to make milk jugs, margarine tubs and water pipes. Low-density polyethylene (LDPE) is soft and flexible, and is used in the manufacture of squeeze bottles, sacks and sheets.
• Polypropylene (PP): Used in reusable plastic containers, diapers, sanitary pads, ropes, carpets, plastic moldings, piping systems, car batteries, insulation for electrical cables, etc.
• Polyvinyl chloride (PVC): Used in the construction industry, such as vinyl sidings, drainpipes, gutters and roofing sheets (as it is resistant to acids and bases).
• Polyethylene terephathalate (PET): Used in beverage bottles, textiles, specialty films, etc.

Polymers. Large molecules composed of many repeated subunits (monomers). Polymers can be synthetic (plastics) or natural biopolymers (such as polysaccharides, DNA, or proteins).

Rebound effect. The behavioral or other systemic responses to the introduction of new technologies that increase the efficiency of resource use. These responses, including energy consumption, usage of natural resources or other inputs (i.e. labour), tend to offset the beneficial effects of the new technology or other measures taken.

Refurbishment. A process of returning a product to good working condition by replacing or repairing major components that are faulty or close to failure, and making ‘cosmetic’ changes to update the appearance of a product, such as cleaning, changing its fabric, painting or refinishing it. Any subsequent warranty is generally less than issued for a new or a remanufactured product, but the warranty is likely to cover the whole product (unlike repair). Accordingly, the performance may be less than as-new.

Remanufacturing. A process of disassembly and recovery at the subassembly or component level. Functioning, reusable parts are taken out of a used product and rebuilt into a new one. This process includes quality assurance and potential enhancements or changes to the components.

Reuse of goods. The use of a product again for the same purpose in its original form or with little enhancement or change. This can also apply to what Walter Stahel calls ‘catalytic goods,’ e.g., water used as a cooling medium, or in process technology.

Supply loops. Forward and reverse logistics setup to facilitate materials/product flows through the system from inputs/raw materials, production, finished goods, and end-of-use products back to raw materials, together with intermediate steps to prolong the product life cycle.

Waste electrical and electronic equipment (WEEE). Discarded electrical and electronic devices that still contain significant valuable materials, including metals (e.g. steel, copper, rare minerals) and plastics.