1. The Quality of an Emission Inventory
Tinus Pulles
CLRTAP International Workshop on Validation and Evaluation of Air Emission Inventories
Session 3
Validation and Review to meet Policy needs
How to assess and manage uncertainties in emission inventories?
Tinus Pulles
TNO-MEP
PO Box 342
7300 AH Apeldoorn
The Netherlands

2. Issues in this presentation
The concept of “data quality”
Quality criteria
How to achieve required quality
Reviews
In this presentation I will give an overview of how I see the different issues related to uncertainty assessment and management within the framework of international conventions and protocols.
I will start riding my favourite horse: the concept of data quality and will extend this ride towards the quality criteria relevant within the policy use of emission inventories
Before diving into the how, I will give my views on why we need to manage uncertainties in the first place.
A short description will be given on the methods developed within the UNFCCC system in the IPCC National Greenhoude Gas Emissions Programme (IPCC-NIGGP)
Assessing and Managing Uncertainties in Emission Inventories
10/15/2002

3. Perspectives on data Quality
Quality high if …
True ?
Scientist
… it produces predictions that are confirmed
Scientific debate:
search for weaknesses and errors; falsification
Accepted ?
Policy maker
… everybody involved agrees
Political debate:
search for consensus and agreement; compromise
Convinced ?
Lawyer
… it convinces a judge or jury
Judicial debate:
search for proof or doubt; persuasion
Assessing and Managing Uncertainties in Emission Inventories
10/15/2002

4. Verification and Validation
Policy oriented quality
Guidelines applied ?
validation
Real world
emissions
Emission
inventory
Science oriented quality
True ?
verification
Assessing and Managing Uncertainties in Emission Inventories
10/15/2002

5. Verification Validation
methods:
Error propagation
Independent checks
Measurements and models
methods:
quality control
auditing
country comparisons
feed back
Reliability
objectives:
Accuracy
(no systematic error)
Precision
(no random error)
objectives:
Transparency
Comparability
Completeness
Consistency
Accuracy
Assessing and Managing Uncertainties in Emission Inventories
10/15/2002

6. Policy oriented inventory: Quality check by UNFCCC
Submitted
Initial Check
“Synthesis and Assessment”
Expert Review
In-depth
finalizes the
Review
Inventory
Accepted
UNECE / CLRTAP
Still under development
Assessing and Managing Uncertainties in Emission Inventories
10/15/2002

7. Three stages of review Initial check Completeness:
Type of review
Objective of review
Stage 1
Initial check
Completeness:
All data provided? (Counts, gaps)
Stage 2
Comparisons and consistencies
Compare with
Earlier submissions (time series, jumps)
Other parties (IEFs)
Stage 3
Explanations and understanding
Finalize and conclude
Discuss and solve any problems between review process and national experts
Ensure that the inventory is adequate and complies with the Guidelines
Report to implementation committee
Assessing and Managing Uncertainties in Emission Inventories
10/15/2002

8. Good practice guidelines
Prepared by IPCC
Accepted by UNFCCC
Contents:
Good practice guidance per sector
Decision trees
Default uncertainty values
Additional information
Methodology
Uncertainty estimation
Key source analysis
QA/QC procedures
Report in CRF & NIR
Similar approach in EMEP/CORINAIR Guidebook for LRTAP
a set of procedures intended to ensure that inventories are accurate in the sense that they are systematically neither over nor underestimates so far as can be judged, and that uncertainties are reduced so far as possible practicable.
Assessing and Managing Uncertainties in Emission Inventories
10/15/2002

9. Decision tree Example Energy
Guides user step by step through the procedure
Supports methodology choice (Tier 1 or Tier 2)
Proposes data to be looked for
Assessing and Managing Uncertainties in Emission Inventories
10/15/2002

10. How to get your inventory accepted
Read the Good Practice Guidance and follow the recommendations
Carefully plan the reporting cycle
Deadlines
Key sources ?
Experts needed
Data needed
Document carefully
all your assumptions
all your data sources
After first cycle use uncertainty analysis and key source analysis to improve your inventory year after year.
Assessing and Managing Uncertainties in Emission Inventories
10/15/2002

11. Thank you Assessing and Managing Uncertainties in Emission Inventories
10/15/2002