LCA Flashcards
What does LCA mean?
Life Cycle Assessment
What is LCA?
method to assess potential environmental impacts over the life cycle of products & services
according to ISO 14040/44
Exists all over the world
What are environmental impacts?
climate change
acidification of soils, waters, acid rain
eutrophication (mostly in water, growth of algues, fish dying…)
ozone layer depletion
….
What is the life cycle of products and services?
- material extraction & energy use
- material production
- product production
- use & maintenance of the product
- recycling
- disposal
–> environmental impacts occur in all stages
What is ISO 14040/44?
Only standardized method to do LCA
What is ISO?
International Organization for Standardization
network of 162 countries to provide practical tools for tackling mang of today’s challenges in regard to Health, Waater, food, Climate change,…
What are the aims of LCA?
determining potential environemntal impacts of a prodcut
identifying (hidden) environmental hotspots of a product
identifying shifts of burden between life cycles and impacts (e.g., reduction of one environmental problem can lead to increase of another one)
–> environmental problem (carbon footprint) (water footprint)
identifying options for environmental improvement
Informing decision makers in industry, government, NGOs, etc.
Marketing (e.g. in the implementation of eco-labels)
What is the use of LCA?
One Product:
- exisiting product can be optimized (combustion engine)
- new product can be designed and optimized (infrastructure for battery driven cars)
Several products:
- select the existing product with the least environmental impact and optimize it (coffee roasting technique)
- design, optimizes and select new products (solar panels)
What is LCA able to do?
Determine the relative impacts of a product not the absolute ones (you need to compare the data!)
What is LCA not able to do?
Cannot determine the real impacts of a product, only the potential ones (info about space and time is needed but not available in studies because life cycle of product takes place all over the world)
–Cannot compare products with different functions
–Cannot give universal statements with regard to materials (depends on how material is used in product)
–Cannot assess social aspects or risks (only environmental)
What does LCA depend on?
–Data quality
–Time (available to do the study)
What does LCA not deliver?
Binary results: yes/no; black/white and can therefore only support decisions
–Not the ONE result but many for different impact categories –> IMPORTANT
What are the recent developments in regard to the use of LCA?
Increasing use in market and policy
for product & process optimization
external communication
transparent supply chains
for environmental labels (blue angel)
Product Environmental Footprint (PEF),a current initiative for implementingLCA,
Of what phases does LCA based on ISO 14040/44 consist?
LCA framework?
1) goal and scope definition
2) inventory analysis
3) impact assessment
4) interpretation
Explain phase 1 of the LCA framework.
goal and scope definition
the following has to be defined:
- goal and reasons for carrying out LCA (e.g. learn about environmental impacts)
- target audience (internal or external?)
- are the results communicated to public? –< critical review is neccessary
- specify functions of system (functional unit and reference flow)
- system boundaries: How does the life cycle of my product looks like? Which processes do I consider? (→product system:e.g., manufacturing, use, recycling, location, …)
What products can be compared?
Only if they have the same function (can be very hard to determine: e.g. chair vs lounge chair) and are from the same company
What is the functional unit?
quantified performance of a product system for use as a reference unit
–> allows comparison of aluminium bike vs bamboo bike
–> functional unit: transportation of a person over 5000 km
What is the reference flow?
measure of the outputs from processes in a given product system required to fulfil the function expressed by the functional unit
–> reference flow: 3x material amount of bamboo bike is needed compared to aluminum bike because bamboo bike does not last for 5000 km
Examples of functional units & reference flows
function: Cover a specific distance, having dry hands
functional unit: riding 15000pkm by bike, drying 1000 pairs of hands
reference flow: by means of one aluminium bike or 1 bamboo bike, by means of 20 cotton towels, 2000 paper towels, 500 m^3 hot air
What is the goal of phase 2 of the LCA.
inventory analysis/ life cycle inventory (LCI)
To compile and quantify the inputs (energy, raw materials, intermediates, auxiliaries) and outputs (waste, waste water&heat, co2, emissions) for a product throughout its life cycle
–> list of input and output
–> most time consuming phase
–> example:
What are the data requirements for an inventory analysis?
•Primary data
–Collected directly at company; e.g. own measurements
–> not possible in real life since data is too big
–> use data that companies have collected already
•Secondary data
–Literature
–Existing LCA case studies
–LCA data bases (e.g., GaBi) & software (e.g. GaBi)
Explain phase 3 of LCA.
life cycle impact assessment (LCIA)
determine potential environmental impacts for a product system
–> to help assessing a product system’s LCI results to better understand their environmental significance
Input/output flows from the LCI are “translated” into potential environmental impacts
–> big amount of data is aggregated to a smaller set of data
What are the LCIA steps?
- selection of impact categories: climate change
- Classification: Allocation of emissions (LCI results) to an impact category
SO2emission→ acidification; CO2/CH4 emission → global warming - Characterization: Multiplication of each emission (LCI) with a characterisation factor (CF)
What is CF in regard to Characterization?
the individual contribution of the emission to the environmental impact
examples:
LCI - CF - global warming potential
10 kg CO2 - 1 - 10 kg CO2 eq.
0,5 kg CH4 - 28 - 14 kg CO2 eq.
LCIA: mid-point vs. end-point categories
Definition of impact indicators in the “middle” or at the “end” of the impact chain
- Mid-point: Scientifically more proven, but more abstract; e.g. human toxicity, radiation, climate chang,.
- End-point:Insecure, but impact as real damage; e.g. loss of human health [YOLL: Years of Life Lost]; [DALY: disability-adjusted life years], resource scarcity
•Both option possible
–> You need to know what to do and how to reflect critically the result.
What happens in the course of the impact chain?
confidence & reliability decrease because you have to make more and more assumptions in the model
significance & validity increase since the results address real life issues
example:
1 kg CO2 is emitted –> increasing malaria frequency due to increase in CO2 –> determine the death rate due to increase of malaria frequency
–makes results better to understand
examples of mid-point & end-point methods
mid point: UBA (Germany)
end-point: LIME (Japan)
combined approach: ReCiPe (Netherlands)
–> doesn’t bring sufficient results for biodiversity
Why are Different results depending on the method!!
•e.g. because of varying number of elementary flows (emissions considered) and different characterization models (regions they consider (global vs european))
Explain the last phase for LCA.
Interpretation.
- discussion and interpreting the raw results from LCI & LCIA to have final results according to goal & scope definition
- Identification of life cycle phases, processes and materials that have a strong impact (e.g., electricity mix for charging smartphones)
•Analysis of effects of parameter fluctuation to overall result & comparison of different scenarios
- Conclusions and recommendations
- Limitations
- Transparent report
