Unit
- Linear economy model: Resources are extracted, processed into products, used by consumers, and disposed as waste. This take-make-dispose approach relies on finite resources and generates growing environmental burdens.
- Circular economy definition: A regenerative system where resource input and waste, emission, and energy leakage are minimized by slowing, closing, and narrowing material and energy loops through long-lasting design, maintenance, repair, reuse, remanufacturing, and recycling.
- Key difference: Circular economy decouples economic growth from resource consumption by designing out waste and keeping materials in productive use at their highest value at all times.
- Butterfly diagram: A visualization by the Ellen MacArthur Foundation distinguishes technical cycles (product reuse, repair, remanufacture, recycling) and biological cycles (nutrient recovery, composting).
- Technical cycle: For non-biodegradable materials, the goal is to circulate products and materials at their highest utility through strategies like sharing, reusing, repairing, and remanufacturing.
- Biological cycle: Biodegradable materials are designed to re-enter the biosphere safely, returning valuable nutrients to the soil and supporting regenerative agriculture.
- Value retention loops: Cascading strategies from narrow loops (e.g., product reuse, less material per product) to broad loops (e.g., recycling) maximize material productivity and reduce environmental impact.
- System-level perspective: Circular economy requires collaboration across supply chains, from raw material suppliers to product designers, retailers, recyclers, and policymakers.
- Circular business models: Companies transition from selling products to offering services, leasing, or sharing models. This shifts incentives toward durability, repairability, and upgradability because the manufacturer retains ownership and end-of-life responsibility. Profit aligns with resource efficiency and product longevity. Examples include pay-per-use for appliances and subscription models for electronics.
- Reverse logistics infrastructure: Effective collection systems for used products and materials are critical for closing material loops. This includes take-back programs, deposit refund schemes, and advanced sorting facilities that enable high-quality recycling and remanufacturing. Well-designed reverse logistics reduces contamination, minimizes material loss, and ensures valuable components are recovered and reintroduced into production.
- Eco-design principles: Focus on creating products that are easy to disassemble, repair, and upgrade. Designers select materials that are recyclable or biodegradable, avoid hazardous substances, and standardize components to facilitate reuse. Modular architecture allows individual parts to be replaced without discarding the whole product, significantly extending useful life and reducing waste.
- Policy and regulation drivers: Government policies such as Extended Producer Responsibility (EPR) require manufacturers to manage product end-of-life, incentivizing circular design. Landfill taxes, recycling targets, and right-to-repair legislation further drive adoption. Green public procurement and eco-labeling help consumers choose circular products, creating market demand for sustainable goods.
Code Example
Python
def calculate_circular_material_index(input_material, waste, lifespan):
reused_ratio = 1.0 - (waste / input_material)
longevity_factor = min(lifespan / 5.0, 1.0)
cmi = (reused_ratio * 0.7) + (longevity_factor * 0.3)
return cmi
product_cmi = calculate_circular_materialQuick Revision
- Review the key concepts covered in Defining Circular Economy: From Linear to Circular.
- Apply these principles in practical working contexts.
- Connect this material to the wider module objectives.