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TDT 1.01 What is a Life-Cycle Analysis?

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What is a Life-Cycle Analysis?

Life-cycle analysis (LCA), also known as life-cycle assessment or cradle-to-grave analysis, is a tool used to evaluate the environmental impact of a product or process.

‘Cradle’ refers to the inputs: for example the raw materials, energy, water, and land used. In coffee, this analysis might include use of fertilisers, plastics for packaging, or energy for roasting — and include an analysis of how each of these inputs is sourced.

‘Grave’ refers to what happens to the materials involved at the end of the product’s life: the environmental cost of recycling or disposing of the waste, the CO2 released during processing, or any chemicals released to the environment. In coffee, this could include disposing of spent coffee grounds or takeaway cups, or the fate of the wastewater from washing stations.

An LCA frequently limits itself to analysis of one element of the environmental impact — for example energy or water use, or greenhouse gas production.

 

Life Cycle Stages

A defining characteristic of an LCA is that it includes the impact of raw materials, production, use, and disposal, simultaneously. For example, a change of material could reduce the CO2 footprint from the manufacturing stage, but result in higher maintenance requirements or shorten the lifespan of the product, thus increasing the CO2 footprint of the usage stage.

The stages in a life cycle analysis. Each stage has its own set of inputs and outputs that must be included in the total analysis. Source: US EPA, 2006

Some analyses may opt to include only some of these stages: for example a ‘cradle-to-gate’ analysis only includes the inputs and outputs up until the point the product is sold, and doesn’t factor in the way the product is used or disposed of.

 

The Four Components of an LCA

An LCA has four components or phases. Each is considered interdependent, in that they inform the way the subsequent phases of the analysis are carried out, but also may need to be revised and revisited as the analysis progresses.

The first phase is Goal Definition and Scope. This sets out the purpose of the analysis and the methods to be used. This might include questions like what outputs should be considered — for example whether to analyse energy use or GHG emissions as the output. These decisions determine how much time and resources the analysis will take, and how meaningful the results will be.

The next phase is analysing the Inventory. This involves identifying and quantifying the inputs and outputs of the process: How much raw material was used? How much CO2 was released?

Impact Assessment then involves looking at the effect of each input and output in the inventory, which can include both environmental and human impacts. For example, an LCA focused on GHG emissions might quantify the relative contribution of both methane and CO2 in terms of their global warming potential.

The final phase is the Interpretation and Improvement Analysis. This evaluates the information from each of the previous three phases, explaining any limitations of the study, analysing the results, and drawing conclusions with a clear understanding of any uncertainty or assumptions made. The interpretation should lead to recommendations based on these findings, that are relevant to the stated goals of the study.

 

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