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Impact Assessment

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Did You Miss Me?

• Real question: Did I miss you? Sydney.

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Did You Miss Me?

• Auckland

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Admin Issues

• FCE Reminder

• HW 3 Final Comments

• HW 4 Due Wednesday

• Project Comments

• Info on “Advanced LCA” Mini (st 4/19/07)

• Impact Assessment Exercise/Lecture

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HW #3 follow up

• This was a group assignment on purpose– In general, if you worked alone you did worse– Although highest grade worked alone

• Question 2 - water allocation / $million• Question 3 - energy IO model

– Think about $-based production functions that form basis of model, do same with energy

– First thing - common units (BTU) - not lbs

• Maybe late, but “what should you turn in”?

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HW #4

• Talk to me with questions (or try Heather)

• Should be straightforward

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Projects

• Listed due date is Thursday 3/8/07– Extensions ok - grades due Mon night 3/12/07– So a day or so more is ok (just ask)– Handed in after Saturday will get Incomplete– Will update grade after deadline

• See original project guidelines – Many of you have changed scope.– Questions?

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Advanced LCA Class

• Mini 4 (starts 3/19)– Not part of “sustainability sequence”– Intended to be a follow-on course in more detail than

what we have done - mostly a guided seminar– Primarily for students who are currently, or expect to

be doing, research involving LCA– We will use software in more depth (e.g., MATLAB,

Excel) and deal with making more robust models with uncertainty

– Will read actual LCA papers and critique– So everyone still invited, just realize its intent/scope!

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Some Environmental Effects

Emission Paper CDs

SO2 35 2Particulates 10 0.1GWP 3000 600RCRA 175 60TRI chems 20 2

(lb)

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Midpoints vs. Endpoints

• Typical LCI result is ‘an emission, waste generation, etc.’ - This is a midpoint

• Breathing emissions, etc. potentially leads to health effects - these are endpoints or impacts

• Now you can see why many studies stop at LCI stage!

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Personal Exercise (< 5 mins)

• Handout on Personal Preferences of Importance of Various Environmental / Energy flows

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Quick Group Exercise (< 5 mins)

• Take your individual exercise results and as a group decide on new results representative of all of you

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Impact Assessment Intro

• Inventory is the last objective step of LCA– e.g., list of estimated inputs and outputs across

life cycle for a product– 12 tons CO2, 4 MJ energy, 4 pounds coal

• But how to actually assess / compare across these? How do we compare them?

• Impact is usually assessed “on ecosystems”• Requires more concrete information than

provided on impact assessment exercise

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Challenges

• Data - as always.– Not enough data to calculate ecosystem damage– No accepted way of calculating damage

• Rules - as with LCA framework, LCIA says to “choose impact categories consistent with scope” and “reference your work”– Again, it has no prescribed categories/impacts that

must be included (eg climate change)

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Impact Assessment (LCIA)

• Mandatory Elements:– Selection (impact categories, their indicators, and

characterization models)– Classification (assigning LCI results to categories)– Characterization (calculation of category results)

• Optional Elements:– Normalization (comparing to reference info)– Grouping (sorting/ranking impact categories)– Weighting (with numerical factors/value choices)– Data Quality Analysis (uncertainty/sensitivity)

• i.e., - at least get things into correct categories

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Classification

• Just what it sounds like– GHGs all in one pile. Ozone depleters, etc.– Some in several piles, e.g. NOx (toxic, acidic,

eutrophication)

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Characterization

• Make effect scores for each category– Uses available weightings to condense

multiple units into a single unit

• GHG example. Use GWP weights (e.g. CO2-equivalents).– CO2 =1– CH4 = 24– N2O = 310, etc.– Effect score is x “GWP” units in CO2-equivs

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LCIA ‘Model’ Example

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

• Should have a comprehensive set of impact categories/indicators• Your own “values” should not bias your model

Source: ISO 14042 Doc

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Sample Output

• What are useful, problematic issues?

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Limitations

• Scientific method combined with values

• Lack of comprehensive focus/boundary

• Category indicators not equally important or precise

• Lack of complete data

• All of this very subjective compared to LCI

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Models

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Eco-indicator

• Will talk about more on Wednesday– See reading on website (read first 20 pages -

sections 1 and 2 - skim rest, including Annex 1)

• A tool to help normalize the characterized effects

• Until then, how might we take our exercise results and make use of them to help?

• What different questions would we ask?