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Task Force on National Greenhouse Gas Inventories

IPCC Expert
p Meetingg on
Use of Models and Measurements in GHG Inventories
9-11 August 2010, Sydney, Australia

Baasansuren Jamsranjav
IPCC-TFI-TSU
Side Event, 29 November 2010, Cancun

Introduction• The expert meeting considered the use of models andmeasurements for all sectors in greenhouse gas emission
inventories.
Essentially these are Tier 3 approaches• In the light of experience to date, the meeting compiled areport on experience and the lessons learnt, particularlyrelated to transparency so that inventory compilersaddressing these issues can benefit from this experience.

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Measured data
• Measured data underlie both models and facility level data.
• Measurements mayy be made at individual pplant coveringg all or ppart ofspecific sub-sectors, and the meeting noted that there are anincreasing number of reporting systems that combine such measured
data with other facility level information.
 Measurements may be of emissions, fuel used, fuel quality etc.

• In general, models use measured data for calibration, evaluation andvalidation to estimate those emissions or removals that cannot beeasily otherwise obtained, and so extend limited information to covernational emissions and removals.

Why use models and facility level data?
• The use of this data in inventories provides significant opportunities toimprovep
the overall qqualityy and,, usually,y, accuracyy of the inventory,y,through, amongst other things,i.
ii.
iii.

reducing uncertainty and improving uncertainty estimates in the national
inventory
improving spatial and temporal resolution of data and further disaggregating
data categories
improving potential to correctly estimate impacts of mitigation on national
inventories by,
by for example
example, reflecting any mitigation effects frommeasurements or by improving inventory stratification• Therefore their use in the national inventory should be encouraged.

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Transparency – key issue• The key issue identified in the use of both models and facility level
data, is transparency
 While approaches to ensuring transparency, documenting and reporting lower
Tier approaches are clearly given in the IPCC Guidelines, the use of models andfacility level data is only discussed more generally as the specifics depend onnational circumstances The 2006 IPCC Guidelines do provide the overall approach to transparently
documenting and reporting these types of data.

• The meeting noted that clearer descriptions of the approaches used toderive national emissions would help ensure the results areunderstandable and credible and that recent experience provides
useful guidance to inventory compilers on how to do this.

Transparency - reporting•Models––Basis and type of model
pp cat o anda d adaptation
adaptat o oof thet eApplication
model
Main equations/processes
Key assumptions
Domain of application
How the model parameters were
estimated
Description of key inputs and outputs
Details of calibration & modelevaluation
Uncertainty and sensitivity analysis
QA/QC
References to peer-reviewed literature–––––––––••

Facility Level Data
Institutional arrangements
–––––

•

Legal basis
Elements covered
Criteria for data selection
QA/QC
Confidentiality

Category-specific––––

Category emissions
Implied emission factor
Uncertainty
How completeness and timeseries consistency are ensured3

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Model considerations• For models the following should be considered:– reasons for model selection– interpretation of model results– calibration and parameterisation– evaluation of model methods, processes and results– comparisons with lower tiers and measurements– uncertainty and sensitivity analysis

Facility level data considerations• For facility level data:– do the facility level data definitions match those of the inventory
and how has this matching been achieved– does the dataset completely cover a reporting category and if not
how this gap has been filled– how has time series consistency between the facility level dataand estimates for earlier years has been achieved– and how might these data enhance the quality of inventories4

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How to encourage the use of this data
• The meeting also considered how the use of these methods can beencouraged– The main barriers to the adoption of complex models are the need forenhanced financial resources and institutional capacity– Access to suitable models, and the ability to modify them, remains a barrier totheir use

• The participants also noted that the use of models requires asignificant, sustained and dedicated effort over the lifetime of themodel to collect and update high quality and reliable data at asuitable resolution and to maintain and adapt suitable models.

Summary• Inventories can be improved by the use of facility level data and morecomplex models– This data can reduce uncertainty,
uncertainty improve stratification and spatial andtemporal resolution, and/or better represent mitigation– Models and facility level data are based on, amongst other things,
measurements– Use of models in inventories implies a long-term commitment to collectand update high quality and reliable data at a suitable resolution and tomaintain the model– If facility level data is used this needs to be matched with moreconventional emission inventory data to complete time series and toestimate all emissions from a sector

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Summary (cont’d.)• Care needs to be taken to ensure the use of either models or facility
level data is consistent with the inventory as a whole and that timeseries consistency is maintained• Transparency is key to using and reporting these data in a clear andcredible way• The IPCC Guidelines outline how this should be done, however:– The Guidelines do not give practical detail or examples– Recent experience can learnt from• The meeting report (under preparation) gives:– Suggestions for reporting transparently based on experience to date
– Topics to be considered and reported in the use of this data

Task Force on National Greenhouse Gas Inventories

Thank you6