Waste BOG Report
Joint 1st and 2nd IPCC Expert Meetingon Short-Lived Climate Forcers (SLCFs)

Outline1. Key Messages & Issues
2. Sectoral Issues
3. Cross-Sectoral Issues
BOG Report

Virtual sessions, 13-20 October 2021

Waste IPCC Categories
4.A Solid Waste Disposal

Emissions from waste decomposition at solid waste disposal sites

4.B. Biological Treatment of Solid Waste

Emissions from the biological treatment of solid waste (e.g., composting & anaerobicdigestion)

4.C. Incineration and Open Burning of Waste

Emissions from the combustion of solid and liquid waste in controlled incineration
facilities (incineration) or from the combustion of unwanted combustible materials directly
into the air (open burning)

4.D. Wastewater Treatment and Discharge

Emissions from the treatment and discharge of domestic, commercial, and industrial
wastewater

4.E. Other waste

No sources currently considered in the GHG GLs

BOG ReportKey Messages from the Waste BOG
Key Categories• Of the five Waste categories, 4.C. Waste Incineration & Open Burning of Waste is a dominantsource of air pollutant emissions. Efforts to develop robust estimates of activity data and EFsfor this category should be prioritizedImpact/Importance of Waste Emissions• Waste emissions from many categories (e.g., landfill fires, landfill flares, open burning) have agreater impact at the local level (e.g., local air quality impacts next to landfills), than at thenational or global level.
Uncertainties• Limited activity and EF data result in large uncertainties in air pollutant emissions from thewaste sector, BUT these uncertainties should not limit efforts to develop robust emission
estimates for Waste

BOG ReportKey Issues from the Waste BOG
Methodological Approach• Available methods (e.g., IPCC, EMEP, USEPA NEI) for many categories may be applicable to a Tier 1approach (or as a starting point to develop a Tier 1 approach)• Flexible reporting while maintaining the IPCC principles of emissions allocation may be beneficial forcategories where emissions can’t be derived at the sub-category level (e.g., emissions from waste
incineration with or without energy recovery)
Activity Data
• There is limited activity data on the amount of waste burned (and burned per capita), composition ofwaste, smouldering or burning conditions, waste disposal approaches in rural areas, etc.,• For Open Burningo The definition of the fraction of waste burned (Bfrac) needs to be clarified
o The estimation of the fraction of population burning waste (Pfrac) should be revisedo The classification of materials included in the definition of agricultural waste burning or land
clearing needs to be clarified so that emissions can be apportioned to the correct sector(AFOLU/Waste) without double counting or missing emissions
Emission Factors• Tier 1 EFs for many categories will need to be region or technology specific (e.g., open wasteburning, biological treatment, etc., )• Some regional EF estimates are available (e.g., EMEP/EEA and US EPA), but others will need to be
developed based on measurements of real conditions

BOG ReportHighlights of Sectoral Issues#1) 4.A – Solid Waste Disposal
Emissions from waste decomposition at solid waste disposal sites#2) 4.B – Biological Treatment of Solid Waste
Emissions from the biological treatment of solid waste (e.g., composting &anaerobic digestion)

BOG ReportSectoral Issue #14.A – Solid Waste Disposal (proposed changes)

Emissions from waste decomposition, landfill fires, and flaring at solid waste disposal sites

Sub-Categories- 4.A.1 – Managed Waste Disposal Sites- 4.A.1.a – Landfill fires (PM (BC/OC), NOx, CO, NMVOC, SO2)
- 4A.1.b – Flaring (PM (BC/OC), NOx, CO, NMVOC, SO2)
- 4.A.1.c – Decomposition (CO, NMVOC, NH3)

- 4.A.2 – Unmanaged Waste Disposal Sites- 4.A.2.a – Landfill fires (PM (BC/OC), NOx, CO, NMVOC, SO2)
- 4.A.2.b – Flaring (n/a)- 4.A.2.c – Decomposition (CO, NMVOC, NH3)

- 4.A.3 – Uncategorised Waste Disposal Sites- 4.A.3.a – Landfill fires (PM (BC/OC), NOx, CO, NMVOC, SO2)
- 4.A.3.b – Flaring (PM (BC/OC), NOx, CO, NMVOC, SO2)
- 4.A.3.c – Decomposition (CO, NMVOC, NH3)

BOG ReportSectoral Issue #2
4.B – Biological Treatment of Solid Waste(proposed changes)
Emissions from the biological treatment of solid waste (composting & anaerobic digestion)

Sub-Categories- 4.B.1 – Composting (NH3, CO, NMVOC)- 4.B.2 – Anaerobic Digestion (NH3)

BOG ReportPossible Cross-Sectoral Issues
4.A Solid Waste Disposal(2 issues)
4.B. Biological Treatment of Solid Waste(3 issues)
4.C. Incineration and Open Burning of Waste(4 issues)
4.D. Wastewater Treatment and Discharge(1 issues)
4.E. Other waste(2 issues)

BOG ReportPossible Cross-Sectoral Issues
4.A Solid Waste Disposal
1. (Energy) Emissions from biogas collected from landfills andused for energy should be in Energy, not Waste
2. (Energy) Emissions from energy used to manage landfill sites
should be in Energy, not Waste

BOG ReportPossible Cross-Sectoral Issues
4.B. Biological Treatment of Solid Waste

1. (AFOLU) Emissions from anaerobic digestion of manure on
farms (storage, digestion, post-storage) should be includedin AFOLU, not Waste.

2. Emissions from anaerobic digestion of manure in treatment
plants (co-digestion with municipal waste, or transported to
an offsite treatment facility) should be included in Waste, notAFOLU.
3. (Energy) Emissions from combustion of biogas collected forenergy use (energy or transport) should be in Energy, notWaste.

BOG ReportPossible Cross-Sectoral Issues
4.C. Incineration and Open Burning of Waste
1.

(AFOLU) Emissions from agricultural waste burning on farms/orchard, etc.
of crop residues (e.g., cereal crops, peas, beans, soya, sugar beet, oil seedrape, etc.), wood, pruning, slash, leaves, plastics, and other general wastes(not transported offsite), should be included in AFOLU, not Waste.

1.

Note: The definition of agr. waste burning needs to be discussed further

2.

(Energy) Emissions from agricultural waste burning for energy should beconsidered in Energy, not Waste.

3.

Emissions from waste incineration (to avoid double counting) …

4.

1.
2.
3.

with energy recovery should be included in Energy, not Waste
without energy recovery should be included in Waste, not Energy
Note: if it is difficult to split emissions between (1) and (2), it will be important that all
waste incineration emissions are reported either under Energy OR Waste and record
where emissions are reported(AFOLU) Emissions from small-scale biomass burning (e.g., land clearing
not at farms) at the site of production, should be included in AFOLU, notWaste

1.

Note: issues of allocation/categorization that may need to be further discussed

BOG ReportPossible Cross-Sectoral Issues
4.D. Wastewater Treatment and Discharge
1. (Energy) – Emissions from the combustion of biogas
collected for energy recovery purposes should be included
in Energy, not Waste
1.

Note: If flared (without energy recovery), included in Waste

BOG ReportPossible Cross-Sectoral Issues
4.E. Other Waste
1. (Energy/Waste) – There are emissions from different
uses/treatment of sludge (e.g., co-firing with coal in cement
industry (Energy), landfilling (Waste), biological treatment(Waste)
2. (AFOLU) – Emissions from sludge spreading should be
included in the AFOLU sector, not Waste.

BOG ReportAny Questions?
Thank you to the Waste BOG participants:
Baasansuren Jamsranjav (TSU)
Hanna-Lii Kupri
Jongikhaya Witi (Facilitator)
Guadalupe Alejandra Martinez Nuñez
Erin McDuffie (Rapporteur)
Marlene Schmidt Plejdrup
Richard Claxton
Steven Smith
Premakumara Dickella Gamaralalage
Betül Demirok (TFB)
Qingxian Gao
Said Abdallah Batouli (TFB)
Rebecca Garland
Kiyoto Tanabe (TFI Co-Chair)
Céline Gueguen
Thomas Wirth (TFB)
Zbigniew Klimont
Patricia Krecl Abad
BOG ReportList of Key Knowledge Gaps
4.A Solid Waste Disposal- Activity Data

- no known guidance available to help countries estimate the amount ofwaste burned at landfills- It may be difficult to find information about flaring efficiencies andvolumes at landfills- EFs- There will be a need to develop regional EFs for landfill fires, flares,
and decomposition (using available methodologies as a starting point)- Other- The significance of NH3 from decomposition needs to be investigatedfurther- Landfill fires and flaring - It is unclear how activity and EF data change
for different landfill types (e.g., managed vs. unmanaged), but weighted
correction factors for different site types may be appropriate to use(analogous to CH4 GHG GLs). This needs to be investigated further.
- The definition of landfill type may also impact whether these is flaring
at unmanaged landfill sites

BOG ReportList of Key Knowledge Gaps
4.B Biological Treatment- Activity Data
- Limited data, especially on amount of greenwaste (composting)- Need to know the amount of N in the feedstock (waste + manure), whichmight vary regionally (anaerobic digestion)- EFs- There will be a need to develop regional EFs for composting (usingavailable methodologies as a starting point)- Lack or limited data about N in feedstocks constraints quality of EFs- Other- Feedstock storage emissions (length of storage period, if stored at all at
the AD site) – consistency with AFOLU to avoid potential double counting

BOG ReportList of Key Knowledge Gaps
4.C Incineration and Open Burning of Waste- Activity Data

- The assumption of no urban burning need to be re-evaluated- The equation to estimate the amount of waste open burned needs to bereviewed and the definition of Bfrac clarified- EFs- Waste Incineration - Need to be technology dependent and account forabatement efficiencies- Available EFs for open burning are not likely globally applicable- Need to develop non-laboratory EFs for tire burning (for tire burning outsideof landfills)- Other- Waste incineration - Emissions will depend on incineration conditions (e.g.,waste moisture content, level of smolder, etc.) and these impacts on EF willneed to be considered further- Open burning - Emissions will depend also on environmental conditions(e.g., soil moisture content, meteorology, etc.) and these impacts on EF willneed to be considered further

BOG ReportList of Key Knowledge Gaps
4.D Wastewater Treatment and Discharge- Activity Data
- It is unclear whether the total amount of wastewater treated at facilities(EMEP method) or the wastewater flow rate (USEPA NEI method) is morereadily available nationally or globally- EFs- Available EFs (NMVOC, NH3 (EPA-only)) are not specific to domestic orindustrial treatment. Domestic EFs for NH3 from EMEP are for latrines
only.

- Other- If Landfill leachate is treated onsite at the landfill include under 4.D.2, [iftreated wastewater is directed to another treatment facility include under
4.D.1. ]BOG ReportList of Key Knowledge Gaps
4.E Other Waste- Activity Data- EFs- Global Tier 1 EF may be able to be derived for car fires- A Tier 1 EF for building fires is likely not globally applicable- Other

BOG Report