Life Cycle Assessment (LCA)

• Life-cycle Assessment is a systematic method for analyzing environmental impacts of products, processes and services over the entire life cycle

• Life cycle assessment

  • can be used by companies to identify which actions have the most impact when determining the environmental footprint of their products

  • quantifies environmental impact along the value chain and thus pinpoints to environmental hotspots

  • hepls to set priorities for mitgating impact and identify effective levers of change

  • it can support corporate environemtal decision making

  • it can be applied both to single products and entire companies alike

• LCA considers the complete life cycle of products, covering the resource consumption and emissions of all processes in the entire supply chain, both up- and downstream:

  • Resource extraction

  • Production

  • Use

  • Disposal

  • Transport

• Finally, LCA calculates what impact the resource consumption and emissions have on the environment

• Application areas of LCA

  • Two distince application areas:

    • Comparison of environmental impacts of various products, processes, activities with the same function

    • Identifying improvement protentials in the life cycle of products

• In this phase we define:

  • What is the purpose of the LCA?

  • Whoe is the intended audience?

  • What are the system boundaries?

• In this phase we must also define the functional unit

  • the functional unit is the reference unit to which all inputs and outputs are referred to (emissions and resource consumptions). It is always quantitative and additive.

  • Example: Compare an energy saving lamp with a conventional light bulb. A good functional unit would be to provide 100 hours of light with a defined brigthness. This way we know we are comparing the same service.

• In this phase

  • We compile all emissions and resource consumptions of the system relative to the chosen functional unit

  • Datbases with standard datasets can facilitate this analysis

  • The result of the inventory analysis is a list of many hundred resoures and emissions for the systems that we analyze

• In this phase:

  • The large amount of information gathered in inventory analysis is aggregated to facilitate comparison

  • First group emissions and resources according to their effects on the environment

    • Example: greenhous gas emissions grouped into “cliamte change“

  • Then, within each impact category we make the emissions comparable with each other

    • Example: for “climate change“, all greenhous gas emissions expressed in CO2 equivalents

  • Goal is to group emissions and resources into 3 to 10 categories

• In this phase;

  • Interpret results from inventory analysis and impact assessment

  • Draw conclusions, discuss uncertainties and provide recommendations

    
    

• Retailer’s goal: Improve supply chain and purchasing processes

• LCA goal: Lower environmental impact of entire vegetable and fruit assortment

Supply chain data:

• The figure below shows an overview of the carbon footprint of the total annual fruit and vegetable sales of this retailer

• Due to the high relevance of asparagus, an in-depth study was performed. In the legend, one can see the different impact categories identified.

• Earlc spring asparagus has higher impact than later season asparagus:

  • Imported mainly from South America via plane

  • Footprint 15x higher than seasonal asparagus

  • Water stress much higher than seasonal asparagus

Results of LCA study:

• Imporvement measures adopted by the retailer:

  • Canceling early-spring promotions on asparagus and thus decreasing the amount of early-spring asparagus sales from South America

  • Changing transportation from airplane to ship transport

  • Changing the sourcing and shifting to nearby production locations

    
    

• LCA suffers from many limitations to its application:

  • It required large amount of data from hundreds of processes

    • Transparencs and peer-review of data necessary

    • Difficult to avoid data manipulation

  • Considerable data uncertainty

    • LCA not always able to provide clear recommendations

    • Nevertheless, LCA improves knowledge and understanding of impact of processes

  • Indiract impacts and rebound effects often neglected

    • Example of rebound effect: if lightbulbs become more efficient, people install more lamps thus offsetting the benefits of the efficiency gain

  • LCA does not cover risks, it assumes average conditions

    • This can lead to questionable results

    • Example: nuclear energy performs great with LCA, as risk of accidents is neglected

  • LCA mainly focuses on environmental dimesntions of sustainabillity

    • Other dimensions are neglected, or approached are still in infancy