Preparatory Work on SLCFs during IPCC AR6 cycle
IPCC Scoping MeetingMethodology Report on Short-lived Climate Forcers (SLCFs): 2027 Supplement to the 2006 IPCC Guidelines
Brisbane, Australia, 26-28 February 2024
Pavel Shermanau
IPCC TFI TSUMandate for Preparatory Work
IPCC49 (May 2019, Kyoto, Japan) decided that IPCC TFI should develop a new Methodology Report on
SLCFs during AR7 cycle with a preparatory work during AR6 cycle (Decision IPCC-XLIX-7):o Approach• The preparatory work for the Methodology Report (including supporting materials and scoping) iscompleted as soon as possible, starting in the AR6 cycle. Followed by further methodologicaldevelopment in the AR7 cycleo Output and Timeline• Expert meetings will produce a series of supporting materials to be published• These supporting materials will be used to inform the scoping of methodological work on SLCF
• The scoping meeting will take into consideration the work on SLCF underway in the AR6 reports of WGIand WGIII• The outline will be presented for approval to the Panel soon after the scoping meetingo Required Activities• Technical analysis work by TFI TSU with other experts• 3-4 Expert meetings• Scoping Meeting• Approval of outline by the PanelTechnical Analysis
o IPCC TFI TSU conducted extensive technical analysis of the main methodological frameworks on
SLCFs source categories and associated emissions:• EMEP/EEA Air Pollutant Emission Inventory Guidebook 2019
• US EPA AP-42: Compilation of Air Pollutant Emissions Factors• UNEP Atmospheric Brown Clouds (ABC) Emission Inventory Manualo This analysis was the basis for discussion at the Joint 1st and 2nd Expert Meeting.

…extensive work…

Technical analysis tables
IPCC codeCategory

SLCFs

IPCC Method

Alternativemethodology

Available EFs/Parameters

Globallyapplicable?

Gaps(if any)

CommentsABCDEFGH

I

Yes, with modification,
the method is slightly
different: fuel andcarbon content (IPCCCO2) per output ofammonia vs. EF of
SLCF per output ofammonia

EMEP/EEA, UNEP, US
AP-42, REAS, MEP China

Yes

2B Chemical Industry
2B1

Ammonia production

NOx, NH3,CO,
NMVOC,SOx

D: In the 2006 IPCC Guidelines, in the case of ammonia production no distinction is madebetween fuel and feedstock emissions with all emissions accounted for in the IPPU Sector.
The method for CO2 and SLCFs is slightly different: input of fuel and its carbon content (IPCCCO2) by output of ammonia vs. EF of SLCF by output of ammonia (SLCF).
F: EMEP/EEA – NOx, CO, NH3. NMVOC - Tier2, Tier 2 - technology specific
UNEP – NOx, CO, NH3, SOx, NMVOCUS AP-42 – NH3, SO2, CO, NMVOCREAS – NH3
MEP China – NMVOC

2B2

Nitric Acid production

NOx, NH3

Yes

EMEP/EEA, UNEP, US
AP-42Yes

F: EMEP/EEA – NOx.
UNEP – NOx and NH3
US AP-42 – NOx

2B3

Adipic Acid production

NOx, CO, NMVOCYes

EMEP/EEA, UNEP, US
AP-42Yes

F: EMEP/EEA – NOx, CO
UNEP and US AP-42 – NOx, CO, NMVOC Excerption from IPPU table

Joint 1st and 2nd IPCC Expert Meeting on SLCFs
o The Joint 1st and 2nd Expert Meeting was held in October 2021 in online format
o Working on the technical documents, the expert meeting successfully achieved its goals:• A complete list of SLCF source categories and associated SLCF species for all sectors – ENERGY,IPPU, AFOLU and WASTE• List of knowledge gaps in all sectors
o All outcomes (the categories list, gaps list, BOGs discussion and conclusions, presentations and tables
for each sector) are part of the meeting report published at the IPCC TFI website:
https://www.ipcc-nggip.iges.or.jp/public/mtdocs/2110_SLCF.html

 The category list will form the futuresectoral outline for Chapters/Volumes ofthe New Methodology Report on SLCFs

Technical analysis tables
IPCC
codeA

Category

SLCFs

BC

2B Chemical Industry
2B1
Ammonia production

IPCC
MethodDNOx, NH3,CO,NMVOC,SOx

Yes

EMEP/EEA, UNEP,
US AP-42

Yes

2B3

Adipic Acid production

NOx, CO, NMVOCYes

EMEP/EEA, UNEP,
US AP-42Yes

CI
In the 2006 IPCC Guidelines, in the case of ammonia production no distinction is made between fuel and feedstock emissions with all emissions accounted for in
the IPPU Sector.
The method for CO2 and SLCFs is slightly different: input of fuel and its carbon content (IPCC-CO2) by output of ammonia vs. EF of SLCF by output of ammonia(SLCF).
EMEP/EEA – NOx, CO, NH3. NMVOC - Tier2, Tier 2 - technology specific
UNEP – NOx, CO, NH3, SOx, NMVOCUS AP-42 – NH3, SO2, CO, NMVOCREAS – NH3
MEP China – NMVOC

NOx, NH32B3

Adipic Acid production

NOx, CO,NMVOCEMEP/EEA – NOx.
UNEP – NOx and NH3
US AP-42 – NOx
EMEP/EEA – NOx, CO
UNEP and US AP-42 – NOx, CO, NMVOC

Gaps(if any)
HCommentsI
D: In the 2006 IPCC Guidelines, in the case of ammonia production nodistinction is made between fuel and feedstock emissions with all emissions
accounted for in the IPPU Sector.
The method for CO2 and SLCFs is slightly different: input of fuel and its
carbon content (IPCC-CO2) by output of ammonia vs. EF of SLCF by outputof ammonia (SLCF).
F: EMEP/EEA – NOx, CO, NH3. NMVOC - Tier2, Tier 2 - technology specific
UNEP – NOx, CO, NH3, SOx, NMVOCUS AP-42 – NH3, SO2, CO, NMVOCREAS – NH3
MEP China – NMVOC

NOx, NH3

B

Nitric Acid production

Yes

Nitric Acid production

Comments

2B2

Globallyapplicable?
G

2B2

SLCFs

NOx, NH3,CO, NMVOC,SOx

F
EMEP/EEA, UNEP,
US AP-42, REAS,MEP China

Category

2B Chemical Industry
2B1
Ammonia production

Available EFs/Parameters

Yes, withmodification,
the method isslightly different:
fuel and carbon
content (IPCCCO2) per output ofammonia vs. EF of
SLCF per output ofammonia

Category List
IPCC
code
A

Alternativemethodology
E

F: EMEP/EEA – NOx.
UNEP – NOx and NH3
US AP-42 – NOx
F: EMEP/EEA – NOx, CO
UNEP and US AP-42 – NOx, CO, NMVOCKnowledge Gaps – IPPU ExampleGeneral gaps:• Lack of AD, additional or different AD can be needed for SLCFs than to GHGs
• Abatement techniques and efficiencies• Availability of regional or country specific EFs for all SLCFs• Definition of BC and OC emissions, measurements standards, availability of EFs for BC and OC, and documentation of EFs with indication of measurement
standards• Definition of VOC (NMVOC), speciation• Allocation of energy and process emissions, in terms of disaggregation between different processes• No agreed climate metrics for SLCFs

Categories gaps:• 2A2 Lime production – Data collection by type of kiln, and abatement• 2B8f Carbon black – BC and OC from diffuse emissions, NMVOCs from storage tanks• 2C1 Iron and Steel – Fugitive PM emissions, SO2 from desulfurization, PM and SO2 from foundries, PM, OC, EC, CO and VOCs from scrap preparation.
Rolling mills – SO2 from use of volatile halogenated organics (VHO)• 2C5 Lead production and 2C6 Zinc production – Data collection of domestic industries (processes, abatement, raw material)• 2C7 Other (Copper) – SO2 from acid mist• 2D3 Solvent use (Domestic solvent use) – Guidance on how to collect AD and on how to estimate AD if there are no statistics (e.g. modelling from a similarcountry etc.)• 2D3 Solvent use (Coating application and Degreasing) – AD
• 2D3 Solvent use (Printing) – Collection of AD (use of ink and/or applied abatement techniques, default efficiencies for abatement are provided in EMEP/EEA)• 2D3 Solvent use (Other Solvent use) – AD capita or product/solvent use• 2D4 Other (Asphalt Roofing) – SO2 emissions in roofing materials• 2F Product Uses as Substitutes for Ozone Depleting Substances – NH3, NMVOC – Methods, AD, EFs• 2H1 Pulp and Paper Industry – Updated EFs

3rd IPCC Expert Meeting on SLCFs
o The 3rd Expert Meeting further considered issues identified at the Joint 1st and 2nd Meeting anddiscussed cross-cutting issues in relation to the inventory of SLCFs emissions taking into accountthe assessments in the IPCC WGI and WGIII contributions to AR6
o It was held in April 2022 in online format
o The discussion was focused on three main topics:• Definitions of SLCF species and methods of their identification/quantification• General inventory issues (Data Collection, Key Category Analysis, Uncertainty Analysis,
Verification, etc.)
 Possible issues for Volume 1 of the New• Refined Category and Gaps’ lists
Methodology Report on SLCFs – General
The meeting report was published on the IPCC TFI website:
https://www.ipcc-nggip.iges.or.jp/public/mtdocs/2204_SLCF_EM3.html

Issues3rd IPCC Expert Meeting on SLCFs
o The 3rd Expert Meeting concluded, among others:• Most BC/OC emission estimates derive from PM2.5, so PM2.5 information is generally available• The priority for NMVOC reporting is to report the total mass of VOC [not by species]• Prioritization should be conducted by source category considering all “air pollutant SLCFs” (i.e. BC,OC, NOX, SO2, NH3, NMVOCs, CO) [all species are important]• It is not recommended to use metrics to compare long-lived GHGs with SLCFs, thus those cannot
be combined in a unique KCA• Given that sources of SLCF emissions are inherently variable and SLCF emissions are impacted byenvironmental conditions, consideration of spatial and temporal occurrence of emissions to relate
those with climatic factors will be important in developing representative emission factors andmethodologies. So, although SLCF information should be reported at minimum national and on anannual basis, finer regional disaggregation or full spatialization of emissions data along with theirseasonality might therefore be needed to capture SLCF emissions accurately for some sources
across all regions of the globe.

Outputs of the Joint 1st & 2nd and 3rd IPCC Expert Meetings on SLCFs
o The following materials were produced:• A complete list of inventory categories with respective SLCF species• Summary tables with relevant information on methods and EFs availability for each categoryfrom: EMEP/EEA Air Pollutant Emission Inventory Guidebook 2019
 US EPA AP-42: Compilation of Air Pollutant Emissions Factors
 UNEP Atmospheric Brown Clouds (ABC) Emission Inventory Manual• A list of knowledge gaps
• A list of allocation issues between different sectors• A note on SLCF species definition and relevance• A note on general inventory issues• A consolidated version of Volume 1 of the 2006 IPCC Guidelines and its 2019 Refinement• English Translation of SLCF methodologies used in China

Category List:Energy

Note on SLCF species –Example for Black Carbon

Meeting Reports

https://www.ipcc-nggip.iges.or.jp/public/mtdocs/1805_Geneva.html
https://www.ipcc-nggip.iges.or.jp/public/mtdocs/2110_SLCF.html
https://www.ipcc-nggip.iges.or.jp/public/mtdocs/2204_SLCF_EM3.html

Conclusiono The participants are able to benefit from the preparatory work in the AR6 cycle:• Technical analysis work
• Expert meetings with supporting materials
o Based on the results of the preparatory work, IPCC TFB drafted the documents for the Scoping meeting.
The most important of them is the Table of Contents (general and sectoral outline) of the Methodology
report on SLCFs.
 see the next presentation

Thank you
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