Life Cycle Assessment (LCA): Quantifying Environmental Impact from Cradle to Grave
Life Cycle Assessment is a standardized method (ISO 14040/14044) for quantifying the environmental impact of a product across all stages of its life: raw materials, manufacturing, distribution, use, and end-of-life. It underpins embodied-carbon claims and eco-labels.
Life Cycle Assessment (LCA) is a systematic framework, formalized in ISO 14040 and ISO 14044, for measuring the environmental impacts of a product or service across its full life: raw-material extraction, manufacturing, distribution, use, and end-of-life treatment. It is the dominant scientific basis for embodied carbon and embodied-energy claims, eco-labels, and product carbon footprint disclosures. A canonical LCA has four phases: goal and scope definition, life-cycle inventory (LCI) of inputs and outputs, life-cycle impact assessment (LCIA) translating those flows into impact categories, and interpretation. Impact categories typically include climate change, ozone depletion, acidification, eutrophication, freshwater ecotoxicity, human toxicity, minerals and metals depletion, fossil depletion, land use, and water consumption. Two LCAs of the same product can produce different numbers because of choices about system boundaries, allocation between co-products, the modelled electricity grid, and the impact characterization model used (e.g. ReCiPe, EF, TRACI). Consequential LCA models marginal changes from a decision; attributional LCA divides existing impacts among products. The ISO standards mandate critical review for comparative claims made public, but in practice many published footprints are screening LCAs with substantial uncertainty.