Each life-cycle stage contributes to a product's environmental footprint through material, energy, and water use, plus emissions and waste. The total footprint must therefore be assessed across the whole product life cycle, not from one stage alone.
In life-cycle analysis (LCA), designers identify inputs and outputs from raw material extraction to final disposal. The significance of each stage depends on the product, lifespan, energy source, transport, and end-of-life pathway.
| Life-cycle stage | Main effects on the environmental footprint |
|---|---|
| Raw material extraction | Mining, drilling, logging, and agriculture can deplete resources, consume energy and water, damage habitats, reduce biodiversity, and cause pollution. Recycled or renewable materials may reduce these impacts. |
| Manufacturing | Material processing, component forming, assembly, and finishing consume energy and may create greenhouse gas emissions, toxic pollution, wastewater, and material waste. Efficient processes and renewable energy reduce impacts. |
| Distribution | Packaging, storage, and transport consume materials and fuel. Impacts depend on distance, mass, volume, transport method, load efficiency, and energy source. Air freight generally exceeds sea or rail impacts. |
| Use | Products may consume electricity, fuel, water, or replacement materials. Energy-intensive products can have their greatest impact here, while durability and efficiency reduce lifetime impacts. |
| Disposal | Landfill can cause resource loss, pollution, and methane emissions, while incineration creates emissions. Reuse, repair, remanufacture, and recycling retain value, but collection and reprocessing require energy. |
A common misconception is that the material with the lowest extraction impact automatically makes the most sustainable product. Changing one stage can shift impacts elsewhere: a heavier durable material may increase distribution impacts but extend product life and reduce replacement.