Antelope LCAAn API for Life Cycle Assessment Modelsand LCIA resultsISSST 2015Dearborn, MI May 18-20

Brandon Kuczenski and Sabina Beraha – UCSB – ISBER Supported by CalRecycle #DRR 13026

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So you’ve done an LCA…

How do you share it with the world?

LCA Reports are “extensive”• Long, information-dense, accessible only to

experts• Static: reports results generated from a

snapshot (or a few) of the model– Only includes the authors’ view

• Unstructured: requires heroic interpretation and data adaptation efforts to re-use data or results– Not to mention, a lot of copy-paste– Makes transparency hard

• Good for ISO review panels (to have something to pore over) and institutional funders (to show that a lot of work was done)

Bad for data users, policy makers, and the general public

What would a data user want to do?• Understand model structure, system boundary,

assumptions, data sources• Validate results• Reproduce results; Parameterize results• Perform independent Sensitivity and Scenario

analysis• Extract data, adapt data, test hypotheses

Don’t you want your data users to be happy?

Take my word for it…

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ILCD recommended methods

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Sign inversions, due to metal uptake

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Factor 1000 error in GaBi for flow Radon 222 long-term to air

Preliminary diagnosis - Results overview – ILCD recommended methods

Speck et al (2015) J. Ind Ecol DOI: 10.1111/jiec.12245 Lesage et al, unpublished

• Most LCAs are made with standard data, at least in the background (Ecoinvent, GREET, US LCI, etc.)

• LCIA Methods should all be standard• Reproducing a study should be easy, but in practice nothing

is straightforward • This is a crisis of provenance

A Web Service for LCA Publishing• Provide a mechanism for LCA study authors to

reproduce their models and study results on the web for data users to access and validate

• Provide a structured representation of the product system model

• Provide the exact LCIA factors used to compute results• Provide static web addresses to obtain LCIA results for

model components• Allow users to adjust the model by specifying custom

scenarios and parameters• Allow access to the source LCI data in XML formats

(ILCD)• Nicknamed “Antelope” for swiftness and agility

ILCD Format• Provides “almost” all entity

types involved in LCA• (Product system models are

the major exception)• Nice schemas and

stylesheets for formatting and data validation

Wolf, Düpmeier, Kusche (2011) EnviroInfo

Life Cycle Inventory Fragments

• Inventory models describe industrial processes• Fragments describe inventory models as trees• Inventory data are referenced to external data sets (ILCD)

Fragments are Workflow models

• Preparing an LCI model is like building a workflow for a physical product• Acyclic foreground model is kept distinct from background (with loops)• Background LCI results are pre-computed

FragmentFlow Model• Fragment Definition:

– FragmentFlowID sequential key– ParentFragmentFlowID (null for reference flow)– FlowUUID– Direction relative to parent– Name– Stage for aggregation– NodeType “activity” or “exchange”– TargetUUID for activities: how to terminate

• Computed during traversal:– ProcessID or FragmentID– NodeWeight– FlowMagnitude (1 for reference flow)– isBackground

Tool Design and Data flow

REST APIREST = “REpresentational State Transfer” has two main principles:• The back-end of the tool is “stateless,” meaning the same

request will always provide the same information– User-generated parameters weaken this provision, but the use of

a computation cache reinforces it. – The cache is recomputed before the request is answered, so the

back-end is never “out-of-state”• Resources returned by the tool should link to other relevant

resources– This is not commonly done in practice– In place, allows a user with no knowledge of the data structure to

explore and to discover resources

Why use a web service?• Web-based resources can encapsulate LCI

computations • A static URI provides a provenance framework for the

results (“says who?” “says me, right here!”)• Data user can determine the level of trust• Web resources can be linked semantically

But especially:• Separates the task of data delivery from data

presentation

Sample QueryQuery: http://localhost:60393/api/processes/1Response:[{ "processID": 1, "referenceYear": "2013", "geography": "US", "referenceTypeID": 1, "dataSource": "Full UO LCA Flat Export BK", "hasElementaryFlows": true, "name": "Metal Emissions, DK MDO", "uuid": "01c96a9f-aeb1-4c5f-bc36-5de9638799f9", "version": "00.00.000", "links": [ { "rel": "reference", "href": "http://localhost:60393/xml/01c96a9f-aeb1-4c5f-bc36-5de9638799f9?version=00.00.000", "title": "Link to ILCD Data Set" }, { "rel": "self", "href": "http://localhost:60393/api/processes/1", "title": "Metal Emissions, DK MDO" }, { "rel": "process flows", "href": "http://localhost:60393/api/processes/1/processflows", "title": "Exchanges for Process"}, { "rel": "cumulative scores", "href": "http://localhost:60393/api/processes/1/lciaresults", "title": "Cumulative LCIA results for all LCIA methods" }, { "rel": "detailed scores", "href": "http://publictest.calrecycle.ca.gov/lcatoolapi/api/processes/1/lciamethods/{x}/lciaresults", "title": "Detailed LCIA results for a single LCIA method" } ], "resourceType": "Process", "isPrivate": false }]

Data Resources• Standard LCA Data Types (from ILCD):– Processes, Flows, Flow Properties, LCIA Methods

• Formal descriptions of an inventory model– “Fragments” and FragmentFlows

• LCIA Computational results– Direct LCIA results for processes and fragments– Sensitivity analysis – Full list of resources at $URL/Help

LCIA Interpretive Support• Contribution Analysis

– Contributions of different nodes or stages in a fragment– Contribution of elementary flows to LCIA results

• Scenario Analysis– Scenarios are defined as deviations from the base scenario model– Several different parameter types:

• Dependency Params modify FragmentFlows• Flow property params (e.g. calorific value)• Flow composition params (special case of flow property params)• Composition-based dissipation factors• Ordinary ProcessFlow emission factors• LCIA Factors

– process / fragment substitution• for modeling different versions of the same process (e.g. 2012 vs 2013 data

year)

• Sensitivity analysis of LCIA results to parameter variations

Live beta test currently running

http://publictest.calrecycle.ca.gov/lcatoolfrontend/

• Slideshows of front-end application:– Top-level fragment; sankey– Sub-fragment– Process node – traversal details– LCIA Waterfalls– Process LCIA – emissions

• All information displayed is obtained via the API

View ControlSankey Diagram(Fragment)

Nodes

Processes

Sub-fragments

Flows

Fragment Navigation

LCIA Results

Reference flow determines activity level

Quantities from data set

Flow Magnitude = Quantity x Activity level

Balance flow magnitude determined from other flows with same unit

Link to data set

Fragment Navigation Go Back

Go Lower

Click for LCIA Method Info

Click to dismiss LCIA method

Emission Contribution Analysis

Click for DetailsMore LCIA Methods…

Conclusions and Future Work• Antelope API provides a provenance framework for LCA

models and results• User-specified scenario and sensitivity analysis• Access to source data sets• (Uncertainty analysis in the future?)• (User-driven fragment construction in the future?)• Acknowledgments:

– Sabina Beraha – front-end developer– Rachel Scanlon – supporting back-end developer– Robert Carlson – CalRecycle project manager– The lubricating oil consuming citizens of California– NSF #1539816 (CBET) – Travel to ISSST