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Life Cycle AssessmentA product-oriented methodfor sustainability analysis
UNEP LCA Training KitModule b – Overview of LCA
• What is LCA?
• Why LCA?
• The ISO 14040 framework
– Goal and scope definition
– Inventory analysis
– Impact assessment
– Interpretation
Contents
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What is LCA? (1)
• Officially:Life Cycle Assessment
• Here confined to:quantitative environmental Life Cycle Assessment of products
– environmental
– Life Cycle
– Assessment
– quantitative
– products
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What is LCA? (2)
• At least three different meanings:– LCA as a field of study– LCA as a technique– LCA as a specific study
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What is LCA? (3)
• Basically: tool for decision-support– computational aspects
• which data• which models• which formulas
– procedural aspects• who to involve• how to report• how to use
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What is LCA? (4)
• ISO-standardised procedure (ISO 14040, created in 1997-2000; revised in 2006)– Structured framework: four phases– Rules, requirements and considerations specified– Specific data and calculation steps not specified– Much attention for transparency in reporting
ISO 14040 framework (1)
- Product developmentand improvement
- Strategic planning
- Public policy making
- Marketing
- Other
Goaland scopedefinition
Inventoryanalysis
Impactassessment
Interpretation
Direct applications:
Life cycle assessment framework
Source: ISO 14040
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ISO 14040 framework (2)
• ISO: Compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product system throughout its life cycle– International Standard ISO 14040– complementary International Standards ISO 14041,
14042, 14043– no Technical Report to 14040, but Technical Reports to
14041 and 14042– 14044 merges the revised 14040-14043 (2006)
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Why LCA? (1)
• Why a product-oriented information tool?
– Increased attention for product policy
• several national policy plans
• EU’s Integrated Product Policy
• UNEP’s International Declaration on Cleaner Production
• etc.
– Influence consumption and production patterns
• clean(er) production
• ecolabel
• product stewardship
• etc.
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Why LCA? (2)
• Why an integrated information tool?– Prevent problem shifting
• to other life cycle stages• to other substances• to other environmental problems• to other countries• to the future
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Why LCA? (3)
• Why a method?– To structure the large amount of complex data– To facilitate comparisons across product alternatives– To enable benchmarking
Why LCA? (4)
• Why complex data?
Product property Incandescent lamp Fluorescent lamp
power consumption 60 W 18 W
life span 1000 hr 5000 hr
mass 30 g 540 g
mercury content 0 mg 2 mg
etc … …D r
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ISO 14040 framework (3)
- Product developmentand improvement
- Strategic planning
- Public policy making
- Marketing
- Other
Goaland scopedefinition
Inventoryanalysis
Impactassessment
Interpretation
Direct applications:
Life cycle assessment framework
Source: ISO 14040
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Phase 1: Goal and scope definition (1)
• Phase of life cycle assessment in which the aim of the study, and in relation to that, the breadth and depth of the study is established– goal definition– scope definition
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Phase 1: Goal and scope definition (2)
• Goal definition:– intended application
• product development and improvement• strategic planning• public decision making• marketing• other
– reasons for carrying out the study– intended audience
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Phase 1: Goal and scope definition (3)
• Scope definition:– function, functional unit and reference flow– initial choices
• system boundaries• data quality• …
– critical review and other procedural aspects
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Phase 1: Goal and scope definition (4)
• Functional unit:– comparison on the basis of an equivalent function– example: 1000 liters of milk packed in glass bottles or
packed in carton, instead of 1 glass bottle versus 1 carton
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Phase 1: Goal and scope definition (5)
• Critical review and other procedural aspects– critical review to ensure the consistency, scientific validity,
transparency of the report, etc.– internal review, external review, review by interested
parties– procedural embedding of LCA: LCA as a (participatory)
process
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Phase 2: Inventory analysis (1)
• Phase of life cycle assessment involving the compilation and quantification of inputs and outputs, for a given product system throughout its life cycle
• Steps:– preparing for data collection– data collection– calculation procedures– allocation and recycling
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Phase 2: Inventory analysis (2)
• Central position for unit process– smallest portion of a product system for which data are
collected• Typical examples:
– electricity production by coal combustion– PVC production– use of a passenger car– recycling of aluminum scrap
Phase 2: Inventory analysis (3)
• Data collection for unit processes:– flows of intermediate products or waste for treatment– elementary flows from or to the environment
electricity production
electricitycoal
generator fly ash
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Phase 2: Inventory analysis (4)
• Combination of unit processes into a product system
• Graphical representation in a flow diagram
electricity production
electricity
coal generator
fly ash
coal mining
equipment
generator production
steel
fly ash treatment
gypsum
system boundary
reference flow
product system
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Phase 2: Inventory analysis (5)
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Source: http://www.fibersource.com/f-tutor/LCA-Page.htm
Phase 2: Inventory analysis (6)
electricity productionwith cogeneration
of heat (CHP)
electricitycoal
generator fly ash
heat
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• Calculation procedures– relate process data to the functional unit (matrix algebra)– allocation of multiple processes (multiple outputs, multiple
inputs, re-use and recycling)
– aggregation over all unit processes in the inventory table
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Phase 2: Inventory analysis (7)
• Inventory table
Elementary flow Incandescent lamp Fluorescent lamp
CO2 to air 800000 kg 50000 kg
SO2 to air 1000 kg 80 kg
Copper to water 3 g 20 g
Crude oil from earth 37000 kg 22000 kg
etc … …
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Phase 3: Impact assessment (1)
• Assessment of the importance of the potential environmental effects with the aid of the results of the inventory analysis
• Steps:– selection and definition of impact categories, indicators
and models– classification– characterisation– normalisation– aggregation and/or weighing
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Phase 3: Impact assessment (2)
Life cycle inventory results
LCI results assigned toimpact category
Category indicator
Category endpoint(s)- forest- vegetation- etc.
Characterisation model
Environmental relevance
Impactcategory
Proton release(H+ aq)
Acidifying emissions(NOx, SO2, etc.assigned to acidification)
Acidification
Cd, CO2, NOx, SO2, etc.(kg/functional unit)
ExampleD
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Phase 3: Impact assessment (3)
• Example of a category indicator– Global Warming:
Global Warming Potential (GWP): measure for Global Warming in terms of radiative forcing of a mass-unit
Example calculation:
5 kg CO2 (GWP = 1)
+
3 kg CH4 (GWP = 21)
=
1 x 5 + 21 x 3 kg CO2 - equivalents (= 68 kg CO2 – equivalents)
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Phase 3: Impact assessment (4)
• Characterisation:• Simple conversion and aggregation of GHGs:
subs
subssubscatcat esultInventoryRCharFactesultIndicatorR ,
CO2, CH4
climate change
GWP (1 and 21) 5 and 3 kg
68 kg CO2-eq
infrared radiative forcing
IPCC climate model
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Phase 3: Impact assessment (5)
• Impact categories, characterisation methods and characterisation models: some baseline examples
impact category category indicator characterisation model characterisation factor
abiotic depletion ultimate reserve irt annual use
Guinee & Heijungs 95 ADP
climate change infrared radiative forcing
IPCC model GWP
stratospheric ozone depletion
strat. ozone breakdown
WMO model ODP
human toxicity PDI/ADI Multimedia model, e.g. EUSES, CalTox
HTP
ecotoxicity (aquatic, terrestrial etc.)
PEC/PNEC Multimedia model, e.g. EUSES, CalTox
AETP, TETP, etc.
photo-oxidant formation
trop. ozone formation
UNECE Trajectory model POCP
acidification deposition/ac.critical load
RAINS AP
... ... ... ...
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Phase 3: Impact assessment (8)
Impact category Incandescent lamp Fluorescent lamp
Climate change 120000 kg CO2-eq 40000 kg CO2-eq
Ecotoxicity 320 kg DCB-eq 440 kg DCB-eq
Acidification 45 kg SO2-eq 21 kg SO2-eq
Depletion of resources 0.8 kg antinomy-eq 0.3 kg antinomy-eq
etc … …
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Phase 3: Impact assessment (7)
• Impact category results still difficult to understand:– difference in units– difference in scale
• Normalisation step to relate the results to a reference value– e.g., total world impacts in 2002– result often referred to as the normalised environmental
profile
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Phase 3: Impact assessment (8)
Impact category Incandescent lamp Fluorescent lamp
Climate change 1.210-11 yr 410-12 yr
Ecotoxicity 1.610-10 yr 2.210-10 yr
Acidification 910-11 yr 4.210-11 yr
Depletion of resources 2410-12 yr 910-13 yr
etc … …
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Phase 3: Impact assessment (9)
• Even after normalisation no clear answer– aggregation of (normalized) impact category results into a
single index– subjective weighting factors needed
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Phase 3: Impact assessment (10)
• Example of a weighted environmental index
Weighed index Incandescent lamp Fluorescent lamp
Weighted index 8.510-10 yr 1.410-10 yr
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Phase 4: Interpretation (1)
• Conclusions, recommendations, analysis, all related to goal and scope of the research– among others based on data quality and sensitivity
analysis– also: critical review by independent experts
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Phase 4: Interpretation (2)
• Example of a contribution analysis
Process Incandescent lamp Fluorescent lamp
Electricity production 88% 60%
Copper production 5% 15%
Waste disposal 2% 10%
Other 5% 15%
Total climate change 120000 kg CO2-eq 40000 kg CO2-eq
Phase 4: Interpretation (3)
• Example of an uncertainty analysis
climate change
0
20000
40000
60000
80000
100000
120000
140000
160000
Incandescent lamp Fluorescent lamp
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