Review Comments by Experts on Second Order Draft of Volume 2 of 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories
Comment ID Volume

To lineComment

ExpertResponse

Authors note

7462

2

Chapter From line
4

215

216

this is an unchanged text but it states that only emissions from fossil fuels should be
regarded in this chapter - however, biogas und charcoal are considered as biomass furthermore, this general explanation would be better between the major header (line 210)
and the first sub-header (line 211)

Jens Reichel

Accepted withmodification

Implemented suggested change. Also included mention of fuel "transformation"
in reference to subchapter 4.3.

3904

2

4

239

241

Exploration is neither mining or handling. The bullet is wrongly placed. Alternatively wecan add "and Exploration" at the top so that it reads "Coal Mining, Handling andExploration"

Andrea TILCHE

Accepted

Good suggestion. Amended heading as suggested.

6958

2

4

267

280

Nobert Nziramasanga
Coal mining smetimes follows a pattern where mining stops for some years and thenresumes either in response to demand or to price or legislation changes. In such cases themine may not apper as abandoned or closed. If emissions are estimated on the basis ofmined tonnage then there may be unerestimation of fugitive emissions. It may be useful forthe guidelines to clarify how such situations may be handled.

Rejected

Abandoned mines methodology is out of scope.

3906

2

4

303

304

Please revisit this sentence. It sounds like a contradiction

Andrea TILCHE

Accepted

Few changes have been made.

248

2

4

364

369

Equation 4.1.2 seems to be incorrect in part of CO2 emissions. Amount of CO2 generated
by CH4 flaring has other chemical nature and is not included in the CO2balance/emissions from coal mining when coal gas was firstly generated. So, probably, "-"has to be changed to "+" for CO2 contained in the secondary gas from coal gas thermal
impact. later on, on the lines 399-400 it's written, "since it is already included via theemission factors, hence no subtraction or addition is needs", if so, CO2 from CH4 that
could be flared but was not (just emitted) has to be included with "+". Sorry, if I'm totallywrong, the description seems still very confused especially taking into account the
specific with EFs in this subchepter. It needs more precise description. One more thing,for CH4, post-mining emissins are inclded. Why not for CO2?

Sergii Shmarin

Accepted withmodification

Please note that: ① Equation 4.1.2 is to be used along with Equation 4.1.1, inorder to adjust for methane utilisation and flaring for Tier 1 and Tier 2
approaches (see lines 379-380); therefore, "emissions from underground mining
CO2”in Equation 4.1.2, is supposed to be calculated with Equation 4.1.1 andthe CO2 emission factor there already covers all the CO2 contained in the seamgas that are likely to be released from underground mining activities, hence nomore subtraction or addition adjustment is needed; ② the Equation has been
modified and the amount of CO2 generated by methane flared or catalyticallyoxidised now is included with "+"; ③ Wording of the text has been further
refined to avoid misunderstandings.④ why CO2 emissions from post-mining
activites are not inclded in Equation 4.1.2? Theoretically it should, however
there is yet no methodology for that, neither in the 2006 IPCC GL nor in the
Refinement. Therefore, we have to ignore CO2 emissions from post-mining
activites in the Equation.

658

2

4

385

386

Equation 4.1.2 elaborated for inclusion CO2: It looks like the equation for reporting CO2
emissions for underground mining activities may result in under-estimation of CO2
emissions, if those originate from recovered coalbed gas burned for energy purposes (notethat CO2 emissions from combustion for energy purposes of recovered coalbed gas arecovered in Chapter 2, Stationary Combustion, of the 2006 Guidelines). It is proposed thatthe authors cross-check Equation 4.1.2 and supporting text to avoid inconsistency with
Chapter 2, Volume 2, of the 2006 Guidelines.

Mikhail Gitarskiy

Rejected

The new text under Equation 4.1.2 in the Refinement has explained why "theamount of CO2 contained in the gas recovered and utilized for energy
production" should be subtracted. If seam gas is recovered and utilized forenergy production purpose, then the CO2 contained in the seam gas is held in
the recovered gas until the later is being consumed. This amount of CO2 (alongwith other carbon-containing components in the recovered gas) would bereported under other relevant source categories (instead of fugitive emissions
from mining activities) depending on the end-use characteristics of therecovered gas. There is no underestimation of CO2 emssionns in Equation
4.1.2, or any inconsistency between the Refinement and the Chapter 2, Volume2, of the 2006 Guidelines.

3908

2

4

424

426

Is it correct to use the word "CANNOT"?. Would it not be better to say "there are no
known methods as of now"

Andrea TILCHE

Accepted withmodification

Text has been amended to reflect the comment. Also amended same issue inlines 728-729.

3910

2

4

433

What are general emission factors?

Andrea TILCHE

Accepted

The adjective "general" has been removed.

2750

2

4

439

440

The text of the flow diagram is not distinguishedAccepted

The figure was revised for the legibility of the text in the figure.

2886

2

4

443

444

The text of the flow diagram is not distinguishedAccepted

The figure was revised for the legibility of the text in the figure.

250

2

4

443

444

There are points (".") or other signs in the end text part of each block exсept for block "aremine-specific data available" in the fig. 4.1.1a. Please, add "?" or delete symbols in otherblocks.

Poot-Delgado Carlos
Antonio
Poot-Delgado Carlos
Antonio
Sergii Shmarin

Accepted"?" has been added.

256

2

4

458

464

Please, unify the units in the subchapter. Here it's writen as m3 tonne-1 and m3tonne-1 online 371.

Sergii Shmarin

Accepted

The mistake in line 371 has been modified.

Comment ID Volume

To lineComment

ExpertResponse

1970

2

Chapter From line
4

466

3120

Annex 4A.1 defines that the default EFs are given at a standard conditions of 15°С and101.325 kPa (1 atm); while Chapter 4.1 (please refer to line 466，497，530，599，758，
781，805，884，1001，1051，1195，1215) provides the densities of CH4 and CO2 at 20°
C and 1 atmosphere pressure. The reviewer would suggest to keep 20°С and 101.325 kPa(1 atm) the standard conditions for natural gas system (meanwhile for oil system, thestandard condition could still be 15°С and 101.325 kPa), since the original 2006 GL has
already made these choices.

DAN YU TIAN

Rejected

In practice, oil and gas system is the aggregated industry. Moreover, several
categories have no distinctions made between oil EFs and gas EFs (e.g., forabandoned wells). For that point, it is reasonable to keep all 4.2 chapter dataconsistent with standard conditions as 15 degrees and 1 atm.

Authors note

252

2

4

478

480

There is a number of punctuation errors. Please, fix it.

Sergii Shmarin

Accepted

2 times comma deleted. 1 semicolon replaced by colon.

2888

2

4

481

484

Reorder bibliographical citations by year and verify bibliographic citation format

Poot-Delgado Carlos
Antonio

Accepted withmodification

254

2

4

481

484

The References are not structured. For example, what's that? Who personally did it, thepeople of Czech Republic, all togather for "Czech Republic 2017"?

Sergii Shmarin

Accepted

Bibliographical citations have been reordered by year; However, thebibliographic citation format, which is required to be Environmental
Conservation style, should be unchanged.
CHMI (2017)National Greenhouse Gas Inventory Report of the Czech
Republic (reported inventories 1990- 2015). Czech Hydrometeorological
Institute, Ministry of the Environment of the Czech Republic, In: p. 491.
SHMU and Ministry of Environment (2017) National Greenhouse Gas
Inventory Report 1990 – 2015 to the UNFCCC and the Kyoto Protocol.,Slovak Hydrometeorological Institute and Ministry of Environment of the
Slovak Republic, 2017 In: p. 448.
Ministry of the Environment and Spatial Planning (2017) Slovenia's National
Inventory Report 2017. Ministry of the Environment and Spatial Planning,
Ljubljana 2017 In: p. 353.

Sergii Shmarin

Rejected

The density of real gases for certain pressure and temperature actually obtains
from real gas state equation. Really the values of compressibility factor
originally finds from experiments or from calculation, as example by virial
equation. But we are not going to add any parts of thermodynamics into
Chapter 4.1 so there is no matter who and where originally applied theoperation of multiplication and division to obtain the CO2 density at 20 °C and1 atm.

Ole-Kenneth Nielsen

Accepted

Changed density value in line 498 to 1.84.

The density of CO2 differs between line 498 (1.839 ● 10-6 Gg m-3) and line 782 (1.84 ●10-6 Gg m-3). Please make this value consistent. The reviewer prefers the later.

DAN YU TIAN

Accepted

Changed density value in line 498 to 1.84.

Are average emission factors the same thing as default emission factors?

Andrea TILCHE

Noted

The text refers to the Average emission factor listed in row 494 above. Have
now inserted "CO2" to make it clearer.

499

Pease, unify the words "Emission Factor/s". With capital letter or with small letter.

Sergii Shmarin

Rejected"emission factor" left as small letters in general text. Left as capital where usedin relation to defining terms in equations.

504

504

Typical for this subshapter. Is the term "basein-specific" a common practice term for thewhole part of 2019 Refinement and IPCC 2006?

Sergii Shmarin

NotedYes, the term "basin-specific" is a common practice term used in Subchapter 4.1
for the existing 2006 Guidelines and the 2019 Refinement. It refers togeological coal basins and that individual coal basins may have distinctive coaland gas characteritistics. Therefore it may be beneficial to develop emission
factors for individual basins, rather than a single country-specific emission
factor. Of course this will vary depending on the countries circumstances andavailablility of data.

714

718

In equation 4.1.6 CO2 underestimation looks to take place because for surface activity
surface atmospheric layer CH4 has to be in place. Compared with CH4 emissions, this fact
is ignored. So, CH4 and CO2 approaches seem to be not comparable logically.

Sergii Shmarin

Accepted

Have added a term for "Post-mining emission of CO2" in Equation 4.1.6 forcompleteness. Have also added clarifying text in 4.1.4.1 noting that while nodefault method is provided for estimating Post-mining emissions of CO2 ,countries can provide their own country-specific emission estimate.

258

2

4

498

498

I propose to change the title of the reference from (GOST 2015) to other one. Because,"GOST" means just "State Standard". Someone or certain institution from certain country
had to perform it. It's just a typical abbreviation in former USSR countries.

4594

2

4

498

498

The density is listed as 1.839E-06 in line 498 but as 1.84E-06 in line 782

1968

2

4

498

782

3912

2

4

499

260

2

4

499

262

2

4

264

2

4

Comment ID Volume

To lineComment

ExpertResponse

Authors note

660

2

Chapter From line
4

717

717

Equation 4.1.6: The equation for reporting CO2 emissions from surface coal mining seems
incomplete. It is proposed that the authors further elaborate on it.

Mikhail Gitarskiy

Accepted

Have added a term for "Post-mining emission of CO2" in Equation 4.1.6 forcompleteness. Have also added clarifying text in 4.1.4.1 noting that while nodefault method is provided for estimating Post-mining emissions of CO2 ,countries can provide their own country-specific emission estimate.

3914

2

4

728

729

Same comment as in lines 424 to 426

Andrea TILCHE

Accepted withmodification

3916

2

4

744

745

This sentence is repeated is repeated in 764. I don’t see the reason for the repetition.

Andrea TILCHE

Accepted

Duplicate sentence has been deleted in lines 744 to 745.

2890

2

4

767

767

Verify bibliographic citation

Poot-Delgado Carlos
Antonio

Accepted

2 punctuation errors have been found and fixed. "Republic of Kazakhstan" hasbeen changed into "Ministry of Energy of the Republic of Kazakhstan".

266

2

4

768

768

References. Please, clarify for Kazakhstan. The people of this country used to work hardly
and alltogather but.

Sergii Shmarin

Accepted

Ministry of Energy (2017) National report of the Republic of Kazakhstan on theinventory of anthropogenic emissions by sources and removals by sinks ofgreenhouse gases not controlled by the Montreal Protocol for 1990-2015.
Ministry of Energy of the Republic of Kazakhstan, Astana 2017, In: p. 393.

4548

2

4

782

782

The denisty of CO2 should be the same for both underground and surface mining. The
value here is rounded to two decimals, while the value on line 498 is provided with threedecimals.

Ole-Kenneth Nielsen

Accepted

Changed density value in line 498 to 1.84.

2658

2

4

783

784

“it is good practice to use the low end of the specific emission range for those mines withaverage overburden depths of less than 25
meters and the high end for overburden depths over 50 meters.” The source should beindicated here.

Xiangzheng Deng

Rejected

Text guidance has been made to be consistent with that for corressponding,existing methane surface mining above. It is also consistent with thefundamental understanding that gas generally increases with depth.

1938

2

4

785

785

The average emissions factor was not modified adequately. The average value should be
modified from 0.65㎥/tonne to 0.44㎥/tonne.

DONGKOO KIM

AcceptedError identified. The text has now been updated.

2892

2

4

891

891

Verify bibliographic citation format

Poot-Delgado Carlos
Antonio

Noted

No action can be taken because comment is out of scope of 2019 Refinement.

276

2

4

978

979

Sorry, table 4.1.5 is shaded but for me it still looks not 100 % logical for low level ofgaseous mines. The older mine, less coal gas would be emitted, Ok. But, if in my country
all the coal mines are not gaseous. So, it doesn't depend on age. It means, that the lowlevel is always 0. Or it has to be mentioned that this table is only for gaseus mines.

Sergii Shmarin

Rejected

No action can be taken because comment is out of scope of 2019 Refinement.

6954

2

4

978

979

Table 4.1.6 (TIER 1 – ABANDONED UNDERGROUND MINES EMISSION
FACTORS) should be extended for further inventory years or it should be completed withthe appropriate equation to allow to be calculated the new inventory year - after 2016. In
the latter case a possible solution would be the use of EQUATION 4.1.12 (with default
values for "a" and "b") multiplied by default "Emission rate at Closure".

Klára Tarczay

Accepted

The abandoned mines methodology is out of scope. However it is acceptable toupdate this table for years beyond 2016.

4550

2

4

978

979

Currently, the tier 1 EF table only lists inventory years until 2016, which has already beenreported. As the values are far from constant, would it not be prudent to expand the list of
inventory years to future proof these guidelines? This could be done be including years up
until 2030.

Ole-Kenneth Nielsen

Accepted

The abandoned mines methodology is out of scope. However it is acceptable toupdate this table for years beyond 2016.

1940

2

4

979

979

No emissions factors were presented for the period after 2016. Emissions factors were
provided only from 1990 to 2016 in Table 4.1.6. It will be a nice alternative to present theemissions factors in a similar way of Tier 2 approach.

DONGKOO KIM

Accepted

The abandoned mines methodology is out of scope. However it is acceptable toupdate this table for years beyond 2016.

268

2

4

981

981

Table 4.1.7 is shaded. Anyway, please fix the word "Eqn" if possible.

Sergii Shmarin

Accepted“Eqn” replaced by “Equation”.

Text has been amended to reflect the comment.

Comment ID Volume

To lineComment

ExpertResponse

Authors note

662

2

Chapter From line
4

1162

1169

Due to economic reasons, it may not be necessary to produce new boreholes to assessannual changes in coal reserves, especially if the coal basin is subject to permanent
exploration and production. Besides, other exploration methods exist, which do not
require construction of boreholes. Consequently, changes in and augmentation of coalreserves do not directly relate to number of exploration boreholes. Meanwhile, the numberof exploration boreholes constructed annually seems more accuarte and adequate
information on corporate (national) exploration efforts. These data are available fromcompanies and national stastic offices. It is proposed that the authors reconcile theguidance on estimating GHG emissions from coal exploration based on augmentation ofcoal reserves and develop the guidance based on the information on exploration boreholes
instead.

Mikhail Gitarskiy

Accepted withmodification

Major coal producing countries do present coal resources on an year-to-yearbasis. These may be ascertained from several governmental and nongovernmental reports and links. Therefore, augmentation of coal resources onannual basis can be obtained to a large degree of accuracy. Number of
exploration boreholes drilled annually seems to be a better option. However,this data is not readily available in national statistics. Therefore, we haveconsidered this approach in a Tier 3 method. Tier 1 and Tier 2 methods basedon augmentation of resorces and depth-wise augmentation of resorces
respectively, can be used if data number of boreholes drilled is not available orcannot be collected from coal exploration agencies or corporates.

1972

2

4

1164

1165

Reference should be provided to support this method of using “the augmentation of coalresources” as activity data for exploration boreholes.

DAN YU TIAN

Accepted withmodification

Please see Section 4.6.1.2 CHOICE OF EMISSION FACTORS. In the lastparagraph of Tier 1 it has been stated that information on fugitive methane
emission from coal exploration boreholes is not usually readily available. The
basis is expert judgement.

3918

2

4

1170

The questions/sentences in the decision tree diagrammes should begin with capital letters.
Some are correct and some are not. It should be uniform. Furthermore, Fig 4.1.4 is not
mentioned in the text.

Andrea TILCHE

Accepted

Decision tree updated.

270

2

4

1170

1170

Please, unify punctuation and capital letters in the blocks.

Sergii Shmarin

Accepted

Decision tree updated.

664

2

4

1170

1171

Figure 4.1.4: The decision tree seems inconsistent with inventory improvement concept,
which builds upon key category analysis. The question, if the category is key, stands in the
beginning of decision trees in the 2006 Guidelines and thus, guides further actions ofinventory compilers. However, it is not included in the present structure of decision tree.
To maintain concictency in decision tree structure, it is proposed that the authors include
key category identification in Figure 4.1.4. It is also proposed to include reference toFigure 4.1.4 in the text of section 4.1.6.1.

Mikhail Gitarskiy

Accepted

Decision tree updated. Reference inserted in line 983.

6138

2

4

1173

1216

I appreciate that the authors clarify the rationale of the default emission factors of coal
exploration under line 1175. However, considering the factors are as per expert opinion, I
consider they have large uncertainty.

Naofumi Kosaka

Accepted

Clarified in section 4.1.6.2.

3920

2

4

1174

"No results are available in the literature" should read "no information is found in theliteraure.

Andrea TILCHE

Accepted

Modified as suggested by the reviewer.

666

2

4

1179

1221

The description of tiers 1 to 3 and of equations 4.1.14 and 4.1.15 is not relevant to subsection 4.1.6.2 (Choice of Emission Factors). It is proposed that the authors move thedescription of tiers and equations to sub-section 4.6.1 that deals with methodologicalchoice. Description of choice of emission factors is retained in sub-section 4.1.6.2.

Mikhail Gitarskiy

Accepted

Text amended. The description of tiers and corresponding equations have been
moved sub-section 4.1.6.1 and the emission factors have been retained in the
sub-section 4.1.6.2.

668

2

4

1182

1204

In the Equations 4.1.14 and 4.1.15, the estimation of methane emissions from coal
exploration builds on augmentation of coal reserves. The proposed estimation method
looks incorrect, because as such, coal reserves are not the sources of greenhouse gas
emissions. The emissions occur with the start of mining activities. With this, a simple
presence of augmented coal reserves cannont be used for emission estimation. The
exploration boreholes constructed annualy are indeed the emission categories. However,
the equations 4.1.14 and 4.1.15 are currently designed in a way that annual augmentationof coal reserves serves the activity data for greenhouse gas emissions released through theboreholes. It is proposed that the authors reconcile the activity data parameters in theequations 4.1.14 and 4.1.15 and replace them with the number of exploration boreholes.
Furthermore, it is proposed that the authors provide default emission factors per
exploration borehole to enable greenhouse gas estimations from coal exploration.

Mikhail Gitarskiy

Accepted withmodification

Major coal producing countries do present coal resources on an year-to-yearbasis. These may be ascertained from several governmental and nongovernmental reports and links. Therefore, augmentation of coal resources onannual basis can be obtained to a large degree of accuracy. Number of
exploration boreholes drilled annually seems to be a better option. However,this data is not readily available in national statistics. Therefore, we haveconsidered this approach in a Tier 3 method. Tier 1 and Tier 2 methods basedon augmentation of resorces and depth-wise augmentation of resorces
respectively, can be used if data number of boreholes drilled is not available orcannot be collected from coal exploration agencies or corporates.

Comment ID Volume

To lineComment

ExpertResponse

6020

2

Chapter From line
4

1190

1193

What would be the recommendation for choosing emission factors? It would be better if
this were indicated in the text, as in the other sections of this chapter, which show intervals
between low and high values.

RENATA GRISOLI

Accepted

Indicated in the text.

Authors note

1974

2

4

1197

1204

Concerning the “Depth-wise Approach”, it may not be a Tier 2 approach since it applies
default EFs.

DAN YU TIAN

Accepted

Necessary coorections have been made.

1976

2

4

1197

1213

Reference should be provided to demonstrate scientific rationality of this method, as well
as source of these default emission factors. If no literature is available to support themethodology and/or the default emission factors, this method shouldn’t be provided in the
body of the 2019 Refinement.

DAN YU TIAN

Noted

The depth-wise approach has been merged with the global average approach.
Additional detail has been provided (lines 1054 to 1060) on the source of theemission factors and method (expert judgement).

272

2

4

1200

1204

Equation 4.1.15. The symbol of sum without numbers of depth types (for example, n=1…
4), looks not so aesthetically attractive. Probably, symbolic clasification of depths would
be in place.

Sergii Shmarin

Accepted

Number of depth types has been furnishesd.

7542

2

4

1222

1231

In the draft is written that augmentation of resources or new addition of resources in theyear may be used as Activity data. From the methods is not clear if activity data in tonnes
year -1 should be used as a augmentation only of coal or lignit and waste, which wasminied together with lignit should be neglected.

Eva Krtkova

Rejected

Mining of coal or lignite is not a part of exploratory borehole drilling.

1978

2

4

1222

1231

There are different categories of coal resources (please refer to “United Nations
Framework Classification for Fossil Energy and Mineral Reserves and Resources 2009”),
the authors should clarify the activity data refers to augmentation or new addition of what
category of “Resource”, to avoid ambiguity.

DAN YU TIAN

Accepted

Additional detali on coal resources has been added, see lines 963-982.

6140

2

4

1222

1231

I suggest that the authors clarify the definition of "resources" used for the activity data ofcoal exploration to avoid a readers' confusion. The following reference is useful: BGR
Energy Study 2017, pages 174 and 176; available athttps://www.bgr.bund.de/EN/Themen/Energie/energie_node_en.html

Naofumi Kosaka

Accepted

Additional detali on coal resources has been added, see lines 963-982.

670

2

4

1226

1226

It is proposed to remove text in line 1226, because it may be incorrect, if augmentation is
not made annually, otherwise coal reserves decrease from year to year.

Mikhail Gitarskiy

Rejected

An alternative equation is unavailable.

3922

2

4

1244

The word chapter is wrongly spelt.

Andrea TILCHE

Accepted

Mistake corrected!

8454

2

4

1244

1244

Please check the correction of word "Chapter".

Pornphimol Winyuchakrit

Accepted

Mistake corrected!

6022

2

4

1244

1244

It is necessary to correct the orthography of the word: "Chapter 5".

RENATA GRISOLI

Accepted

Mistake corrected!

3924

2

4

1260

1261

"….uncertaintly be in the range…." there is a word missing

Andrea TILCHE

Accepted"may" inserted
now it written as:
known, uncertainty may be in the range of ±1 – 2 percent.

3926

2

4

1264

It is not clear which two type of sources are referred to in this sentence

Andrea TILCHE

Accepted

Sentence rephrased…
now it´s written as:
As combination of these effects the uncertainties in Tier 1 approach may begreater or smaller by a factor of 2.

4552

2

4

1273

1273

The sentence needs some work, e.g. Two sources have been identified with potential
emissions, but are not included with a methodology in these guidelines. These two sources
are …

Ole-Kenneth Nielsen

Accepted

Text has been amended to incorporate the suggested wording.

2044

2

4

3893

3895

China State Administration of Coal Mine Safety. (2012) Compilation of Measurement
Data for Classification of

DAN YU TIAN

Noted

This comment is incomplete and doesn't convey any useful message.

Comment ID Volume

Chapter From line

To lineComment

ExpertResponse

Authors note

It is common that GHG inventory estimations are improved by adopting measured
emission factors to achieve tier 2 or higher emission factors. In coal mining upgrading ofdefault to higher emission factors may be distorted by measuring emissions from minesthat have been in operation for some time. This is because gas would have escaped fromunmined seams more than during before mining commenced. Even though this likely
addressed during the research process it may be useful to list such cases as areas needing
special attention.

Nobert Nziramasanga

Noted

No action can be taken because comment is out of scope of 2019 Refinement.

Please, look once more. Probably, it's better to use "NA" instead of "NO" based on
Decision 24/CP.19 (Iin force).

Sergii Shmarin

Rejected

The UNFCCC and the IPCC are different processes even when emissions
estimates submitted to UNFCCC are based on IPCC methodology. Most
importantly, is that the reviewer misunderstood the definition of “NA”, which
belongs to categories that occur but emissions from them are not expected. So
the decision tree is correct in this regard.

1828

The leters in the equation are very smal. Could you please make it bigger.

Sergii Shmarin

Rejected

Such formatting issues will be addressed with the final report.

1829

1830

Table 4.2.3 looks not so aesthetically attractive.

Sergii Shmarin

Accepted

4

1945

1946

Table 4.2.6. For the uncertainties of -50-130 % the rounding level seems too "accurate"
especially for the values "5.848" and "0.261" as well as their sizes differ (stylistically).

Sergii Shmarin

Accepted

Changed to two digits.

2

4

1945

1946

For aviation fuel (gasoline) the uncertaint might be higher then for diesel.

Sergii Shmarin

RejectedYes, it is right. But this EF is a aggragated data for oil refinary.

286

2

4

2018

2019

Could you, please, check once more the units of measurement for the table 4.2.7. Values
per well may be a potential mistake (compared with mass units).

Sergii Shmarin

Accepted

We have rechecked the values and they are correct.

288

2

4

3136

3137

Please, change commas to points where necessary.

Sergii Shmarin

Rejected

Current use is consistent with style guidelines.

672

2

4

1546

1564

Mikhail Gitarskiy

Rejected

The question on key category is at the end in practically almost all decision
trees in the energy volume. Therefore this decision tree is in line with almost all
decision trees in volume 2.

674

2

4

1613

1614

Decision trees in Figures 4.2.2 to 4.2.5 are inconsistent with the concept of preparationand improvement of national inventories, which builds upon key category analysis. In the2006 Guidelines, the question if the category is key, stands in the beginning of thedecision tree, thus, guiding further actions of inventory compilers. However, in thedecision trees in Figures 4.2.2 to 4.2.5, this question is in the bottom, which seems
inconsistent with general guidance in Volume 1 of the 2006 Guidelines. It is proposed thatthe authors reconcile the decision trees and make them consistent with the generalguidance provided in Volume 1.
Table 4.2.1 provides description of operations in oil and gas industry. It is proposed tomove it to section 4.2.2.1, which is about methodological choice. It is further proposed toinclude sub-titles "Operations with natural gas" and "Operations with oil" in table 4.2.1 toimprove its clarity.

Mikhail Gitarskiy

Accepted withmodification

See comment No. 6690.

676

2

4

1823

1828

It is proposed that the authors move Equation 4.2.9 and related text to methodologicalchoice section (Section 4.2.2.3). It is further proposed that the authors include thereference to equation 4.2.9 in the text of the 2019 Refinement.

Mikhail Gitarskiy

Accepted withmodification

1 - Section 4.2.2.2 contains recommendations on method (Tier) choice andcommon equations for Tier 1, which can be applied to any category. Section
4.2.2.3 is devoted to EFs choice. Equations of section 4.2.2.3 are aimed toclarify application of the EFs. Reallocation of the equation is not reasonable.
2 - The reference to relevant equation has been included in the text.

678

2

4

1829

1830

It is proposed that the authors check the units in last column of Table 4.2.3. It looks likesome parameter is missing for the units for Oil exploration.

Mikhail Gitarskiy

Accepted

680

2

4

1902

1964

It is proposed that the authors move Equations 4.2.10, 4.2.11 and 4.2.12 together with
their related text to methodological choice section (Section 4.2.2.3). It is further proposedthat the authors include references to equations 4.2.10 to 4.2.12 in the text of the 2019
Refinement.

Mikhail Gitarskiy

Accepted withmodification

682

2

4

1920

1924

Equation 4.2.11 seems incomplete. It is proposed that the authors cross-check the equation
and revise it.

Mikhail Gitarskiy

Accepted

6960

2

4

274

2

4

1557

1558

278

2

4

1823

280

2

4

282

2

284

Correction made.

1 - Section 4.2.2.2 contains recommendations on method (Tier) choice andcommon equations for Tier 1, which can be applied to any category. Section
4.2.2.3 is devoted to EFs choice. Equations of section 4.2.2.3 are aimed toclarify application of the EFs. Reallocation of the equation is not reasonable.
2 - The reference to relevant equation has been included in the text.
Changed.

Comment ID Volume

To lineComment

ExpertResponse

Authors note

684

2

Chapter From line
4

2058

2062

It is proposed that the authors move Equation 4.2.13 and related text to methodologicalchoice section (Section 4.2.2.3). It is further proposed that the authors reconcile theequation 4.2.13 to include the legend. Furthermore, it is proposed to include the emissions
from natural gas flaring in the Equation 4.2.13, if appropriate.

Mikhail Gitarskiy

Accepted withmodification

1 - Section 4.2.2.2 contains recommendations on method (Tier) choice andcommon equations for Tier 1, which can be applied to any category. Section
4.2.2.3 is devoted to EFs choice. Equations of section 4.2.2.3 are aimed toclarify application of the EFs. Reallocation of the equation is not reasonable.
2 - Legend to the equation has been included in the text.
3 - It it assumed that flaring is already covered by EFs.

686

2

4

2063

2063

Table 4.2.9: It is not clear from the Table 4.2.9 and supporting text, what operations(emission categories) are included in the emission factor for conventional gas exploration.
In particular, it is not clear, if the natural gas flaring is included in the aggregate category(note that in the 2006 Guidelines a separte emission factor was provided for natural gas
flaring). It is proposed that the authors clarify, if natural gas flaring is included in theemission factors referred to in Table 4.2.9.

Mikhail Gitarskiy

Accepted withmodificationline 1890 we state: “In the table below, several options for onshore exploration
emission factors inclusive of venting, flaring, and leaks are presented.”

688

2

4

2063

2063

It is proposed that the authors cross-check units for emission factors in the last column ofTable 4.2.9. In particular, it seems that the indication of number of wells is not included in
description of units in the last column of the table.

Mikhail Gitarskiy

Accepted

690

2

4

2110

2203

It is proposed that the authors move to methodological choice sub-section 4.2.2.3
Equations 4.2.14 to 4.2.17 together with correponding text. It is further proposed that thelegends are provided for the Equations 4.2.14 to 4.2.17.

Mikhail Gitarskiy

Accepted withmodification

1 - Section 4.2.2.2 contains recommendations on method (Tier) choice andcommon equations for Tier 1, which can be applied to any category. Section
4.2.2.3 is devoted to EFs choice. Equations of section 4.2.2.3 are aimed toclarify application of the EFs. Reallocation of the equation is not reasonable.
2 - Legend to the equation has been included in the text.

692

2

4

2063

2205

As follows from Tables 4.2.9 to 4.2.12, default emission factors for on-shore explorationand production of natural gas were developed based on the data from one geographicalregion which is North America. However, the guidance in the 2006 Guidelines andprevious IPCC inventory guidelines aims at coverage of all geographical regions, wheresuch human activites occur. To enhance geographical coverage of natural gas operations in
the 2019 Refinement, it is proposed that the authors include in Annex 4A.2 default
emission factors for gas operations disaggregated by major geographic regions, wheresuch operations occur. The default emission factors for natural gas operations in East
Europe and West Asia are provided in the attached file. It is proposed to include them in
the Annex 4A.2.

Mikhail Gitarskiy

Accepted withmodification

1) Add a sentence on line 1561-1564. "While the emission factor options aremeant to cover technologies and practices that are common in the oil and gas
industries, technologies and practices can vary significantly. In addition, theaccuracy of factors is dependent on the uncertainty of underlying data. A
country should periodically assess changes in technologies and practices, andchanges in available emissions data, and consider updating estimates using atleast a Tier 2 approach, per good practice."2) The data provided by the commenter will not be included in the text orannex, based on following reasons: ① : the EFs provided from the commentor
comes, basically, from a case study performed in 1998 in Western Siberia(Dedikov et.al, 1999) when on-site measurements were carried out to test theCH4 fugitive/venting rate in natural gas production and transmission systems. A
new study (Uvarova et.al, 2017) performed in 2016 figured out the chemicalcomposition of natural gas in the Russian Federation, including its CO2 content,
by using fugitive/venting/flaring rates measured in 1998 (Dedikov et.al, 1999)
and CO2 EFs were developed.② a peer reviewed study in 2010 concluded theemission factors identified by (Dedikov et.al, 1999) is not applicable to reflect
the real situation nowdays in this region.
(S. Lechtenböhmer & C. Dienst (2010) Future development of the upstream
greenhouse gas emissions from natural gas industry, focussing on Russian gas
fields and export pipelines, Journal of Integrative Environmental Sciences,
7:S1, 39-48, DOI:10.1080/19438151003774463)

694

2

4

2205

2205

It is proposed that the authors cross-check units for emission factors in the last column ofTables 4.2.12 and 4.2.13 and make them consistent with the units provided in other tables,
namely Tables 4.2.9 to 4.2.11.

Mikhail Gitarskiy

Accepted

696

2

4

2332

2333

It is proposed that the authors change the order of presentation of tiers in Table 4.2.14 tostart with tier 1. It is further proposed that the authors elaborate on description of primarysources for tier 1.

Mikhail Gitarskiy

Accepted withmodification

Changed labels to clarfy that it’s new gas wells drilled in a year.

Fixed the formatting on the last column.

1) Changed the order of table 4.2.14.
2) Detailed description of primery sources for tier 1 is provided in section
4.2.2.3

Comment ID Volume

To lineComment

ExpertResponse698

2

Chapter From line
4

2340

2340

It is proposed that the authors change the heading of Table 4.2.15 to "Activity Data Values
Required for Use in the Tier 1 Approach to Estimate Fugitive Emissions from Oil and Gas
Systems", which seems more appropriate to the content of the table.

Mikhail Gitarskiy

Accepted

Edited sentence to delete "Guidance on obtaining the"Authors note

710

2

4

3065

3103

It is proposed that the authors provide default temperature conversion factors for oil,similar with those provided for gas (Table 4A.1.1). The temperature conversion factors foroil should be provided on volume to volume and mass to mass basis for the major types ofoils referred to in the 2006 Guidelines.

Mikhail Gitarskiy

Rejected

The conversion factors for oil can not be provided similar with those provided
for gas. The conversion of oil may be performed on oil density basis. Oil
density may vary in broad scale. There are around 30 pages of values ofpossible oil densities. Including these pages in the GLs is not reasonable. The
references on documents, from which the densities may be taken, are provided.

712

2

4

3125

3128

It is proposed that the authors enhance description of disaggregation parameters in tables
4A.2.1 to 4A.2.5 in the Annex 4A.2, to explain how these were derived and to justify theirvalues.

Mikhail Gitarskiy

Accepted

Added text.

714

2

4

3142

3143

The disaggregation for tier 1 of the emission factors for gas exploration and gas
production is not included in the Annex 4A.2, while they are important segments of oil andgas industry being significant source categories for some countries. It is proposed that theauthors develop desaggregation of tier 1 emission factors for gas exploration andproduction and include these tables in the Annex 4A.2.

Mikhail Gitarskiy

Accepted

Gas production disaggregation was already in SOD, edited annex to add othersegments.

716

2

4

3149

3150

In the sub-section 4.2.2.3 of the 2019 Refinement, the default emission factors for onshore
exploration and production of natural gas in Tables 4.2.9 and 4.2.10 were developed basedon data from one geographical region which is the North America. The parameters forother geographical regions were not included. This resulted in limited geographicalcoverage of gas producing regions of the world. This approach is inconsistent with theconcept of geographical coverage applied in the 2006 Guidelines and previous IPCC
inventory guidelines. To enhance geographical coverage in the 2019 Refinement, it is
proposed that the authors include in the Annex 4A.2 default emission factors for gas
operations for major geographic regions, where such operations occur. The default
emission factors for natural gas operations in Eastern Europe and Western Asia areprovided in the attached file. It is proposed to include them in the Annex 4A.2.

Mikhail Gitarskiy

Accepted withmodification

1942

2

4

1830

1830

Table 4.2.3 is hard to read because the head and body of the table are separated into
several pages.

DONGKOO KIM

Accepted

1944

2

4

1909

1909

Table 4.2.4 is hard to read because the head and body of the table are separated into
several pages.

DONGKOO KIM

Accepted

1946

2

4

1926

1926

Table 4.2.5 is hard to read because the head and body of the table are separated into
several pages.

DONGKOO KIM

Accepted

1948

2

4

2063

2063

Table 4.2.9 is hard to read because the head and body of the table are separated into
several pages.

DONGKOO KIM

Accepted

1950

2

4

2117

2117

Table 4.2.10 is hard to read because the head and body of the table are separated into
several pages.

DONGKOO KIM

Accepted

1952

2

4

2159

2159

Table 4.2.11 is hard to read because the head and body of the table are separated into
several pages.

DONGKOO KIM

Accepted

1954

2

4

2205

2205

Table 4.2.12 is hard to read because the head and body of the table are separated into
several pages.

DONGKOO KIM

Accepted

1956

2

4

2249

2249

Table 4.2.13 is hard to read because the head and body of the table are separated into
several pages.

DONGKOO KIM

Accepted

See comment No.692.

Comment ID Volume

ExpertResponse

1958

2

Chapter From line
42584

To line2584

Table 4.2.16 is hard to read because the head and body of the table are separated into
several pages.

Comment

DONGKOO KIM

Accepted

Authors note

1980

2

4

1920

1924

Error in Equation 4.2.11, “Amarine tanks•” should be “Amarine tanks• EFmarine tanks”

DAN YU TIAN

Accepted

Changed.

1982

2

4

1928

1946

EU ETS as well as US EPA Mandatory GHG Reporting Guidance prove that there is an
important emission source - coke burn-off emissions during catalyst regeneration in “1 B 2
a iv Refining”, it could be classified as a process venting. Do the emission factors for oil
refining provided in Table 4.2.6 (as well as TABLE 4A.2.2) take into account thecontribution of catalyst regeneration? If not, the reviewer would suggest to add somemethodical descriptions for catalyst regeneration in section “1 B 2 a iv Refining”.
Otherwise this emission source will be missing.

DAN YU TIAN

Accepted

A box has been provided to make this issue more clear.

1984

2

4

1974

1974

The reviewer would suggest to change “under 1 B 2 a iii 6” into “under 1 B 2 a vi other”,
since the authors renew the IPCC code for fugitive emissions from oil and natural gas
systems (see table 4.2.15 in the 2019 Refinement), the original IPCC code (at Table 4.2.1
in Volume 2 Chapter 4 of the IPCC 2006 Guidelines) should not be used any more.

DAN YU TIAN

Accepted

Changed.

1986

2

4

2058

2062

Error in Equation 4.2.13, “A• EFunconventional gas with flaring or recovery” should be“Aunconventional gas with flaring or recovery• EFunconventional gas with flaring or
recovery”

DAN YU TIAN

Accepted

Corrected variable "A"

1988

2

4

2146

2147

The reviewer would suggest that emissions from town gas production processes should
follow the methodological guidance developed in section 4.3.2.4 GASIFCATION
TRANSFORMATION PROCESSES, and should be reported under “1 B 1 C Solid Fuel
Transformation”. Furthermore, Volume 3 Chapter 3.11 “Hydrogen Production” clearlystate that “emissions from production of hydrogen as part of mixtures with other gases,
e.g., syngas, are not covered …”

DAN YU TIAN

Accepted

The reference has been changed to the transformation chapter. However, no
explicit methodology can be found there. Although it is possible to use theoutputs of CtL to Hydrogen Production, the process analysed in the 2019
Refinement 2006 Guidelines was restricted to the Syngas production.

1990

2

4

2253

2254

The reviewer would suggest to change “under 1 B 2 b iii 6” into “under 1 B 2 b vi
other”, since the authors renew the IPCC code for fugitive emissions from oil and natural
gas systems (see table 4.2.15 in the 2019 Refinement), the original IPCC code (at Table
4.2.1 in Volume 2 Chapter 4 of the IPCC 2006 Guidelines) should not be used any more.

DAN YU TIAN

Accepted

2046

2

4

1349

1391

Footnote 3：Town gas (also called coal gas) is a manufactured gaseous fuel produced forsale to commercial and residential consumers.

DAN YU TIAN

Noted

No action can be taken because comment does not require any substantial reactio

2472

2

4

1920

1925

please check the formula

Mingshan Su

Accepted

Changed.

2474

2

4

2058

2062

please define the variables in the formula

Mingshan Su

Accepted withmodification

2894

2

4

1546

1547

The text of the flow diagram is not distinguishedPoot-Delgado Carlos
Antonio

Accepted

The decision tree has been updated with clearer text.

2896

2

4

1551

1552

The text of the flow diagram is not distinguishedPoot-Delgado Carlos
Antonio

Accepted

The decision tree has been updated with clearer text.

2898

2

4

1557

1558

The text of the flow diagram is not distinguishedPoot-Delgado Carlos
Antonio

Accepted

The decision tree has been updated with clearer text.

2900

2

4

1996

1996

Verify bibliographic citation format

Poot-Delgado Carlos
Antonio

Accepted

Corrected variable "A"Comment ID Volume

Chapter From line

To lineComment

ExpertResponse

Poot-Delgado Carlos
Antonio

Accepted

In the Box4.2.1, it should make clear whether the emission from producing hydrogen as aintermediate product for oil refineries are already accounted for methodology of fugitive
emissions from oil refinering

Eunae Seo

Rejected

The footnote in table 4.2.4c explains what processes are included in the EF H2-production is not included in the EF.

"Town gas originates from outgassing of hard coal under air exclusion in retort furnace or
chamber kilns. Emissions from these processes are considered in Volume 3 Chapter 3.11
Hydrogen Production." But no estimation method is provided in Vol. 3, Ch. 3.11, since
town gas is not pure H2 formed by complete oxidation of the feedstock. Suggest torephrase or remove the reference to Vol. 3, Ch. 3.11.

Håkon F. Skullerud

Accepted

The reference has been changed to the transformation chapter. However, no
explicit methodology can be found there. Although it is possible to use theoutputs of CtL to Hydrogen Production, the process analysed in the 2019
Refinement 2006 Guidelines was restricted to the Syngas production.

1425

There are some missing words in this sentence. It seems.

Andrea TILCHE

Rejected

We do not see any missing words in this line.

4

1751

Should't there not be an "s" after "Factor"

Andrea TILCHE

Noted

No action can be taken because comment is out of scope of 2019 Refinement.

2

4

1814

1815

The word "Conventional" needs to be defined

Andrea TILCHE

Rejected

The term “conventional” is defined both in line 1423 and later in the glossary.

3934

2

4

1857

1858

The sentence needs to be revisited. It would better read "onshore and offshore oil
production".

Andrea TILCHE

Rejected

This comment is incorrect. Such change will confuse users.

3936

2

4

1880

The word "by" may be replaced by the word "through"Andrea TILCHE

Accepted

Changed.

3938

2

4

1930

Please put the Box number

Andrea TILCHE

Accepted

Added box # to sentence.

3940

2

4

1945

Table 4.2.6 is not referenced in text - it seems.

Andrea TILCHE

Accepted

Added reference in text.

3942

2

4

1952

I do not understand the use of the word "regard"

Andrea TILCHE

Accepted

Changed.

3944

2

4

1968

This sentence has no verb

Andrea TILCHE

Accepted

3946

2

4

2052

Please put the equation number in the text - just a suggestion

Andrea TILCHE

Accepted

We revise; “This segment includes fugitive emissions (leaks, venting andflaring) from oil systems that are not otherwise accounted for in the othercategories”
Added equation number.

3948

2

4

2074

Please put the table number in the text - just a suggestion

Andrea TILCHE

Rejected

The number is already incldued in the text.

3950

2

4

2111

Please put the equation number in the text - just a suggestion

Andrea TILCHE

Accepted

3952

2

4

2151

Please put the equation number in the text - just a suggestion

Andrea TILCHE

Accepted

3954

2

4

2195

Please put the equation number in the text - just a suggestion

Andrea TILCHE

Accepted

3956

2

4

2237

Please put the equation number in the text - just a suggestion

Andrea TILCHE

Accepted

3958

2

4

2443

Please a capital "T" in the word table.

Andrea TILCHE

Accepted

Edited

3960

2

4

2521

Please put the verb "is" after equipment

Andrea TILCHE

Accepted

Edited

3986

2

4

3126

"%" should be written in full

Andrea TILCHE

Accepted

Edited

2902

2

4

2010

2010

Verify bibliographic citation format

3406

2

4

1937

1945

3414

2

4

2146

2147

3928

2

4

3930

2

3932

1969

Authors note

ChangedComment ID Volume

To lineComment

ExpertResponse

Authors note

4554

2

Chapter From line
4

2225

2227

Usually, biogas will only have a similar methane content to natural gas if upgraded andeven then it might not be the case. If it is not possible to derive and included biogas EFs,
then it would be good in the text to describe the diffrences between biogas and upgradedbiogas and also whether the CH4 EFs provided can be scaled using the CH4 content of thebiogasOle-Kenneth Nielsen

Rejected

We assume that biogas was upgraded before added in natural gas distribution
systems (see sentence in lines 2226-2227).

4556

2

4

1546

1547

Currently, the decision tree could be interpreted that if the category 'natural gas systems' isa KC, then you have to use tier 2 for everything. I.e. is gas exploration, production etc.
makes 1B2b a KC then you should also use tier 2 for town gas distribution and various
other minor sources within the category. I trust this is not the intention! In agriculture, thisis solved by adding a further criteria that the subactivity should be significant (in the caseof agriculture that the animal species is significant, to avoid having to use tier 2 for 15
horses because enteric ferementation is a KC due to cattle). I suggest adding some similar
wording in this chapter when the decision tree covers many different sub-activities.

Ole-Kenneth Nielsen

Accepted

The decision tree has been updated to clarify that "significant" segments aretreated differently from smaller subcategories. Significant is defined in volume
1.

4558

2

4

1551

1552

I think that the text 'If emissions from oil and gas operations are a key category, arecontributions by the oil system significant' needs clarification. The decision tree is limited
to crude oil production, so either the criteria could be whether crude oil production was a
key category, or whether crude oil production is significant to the whole category, either
1B2 or 1B2a to be defined). Also, similar as to what is done in agriculture 'significant'should be defined.

Ole-Kenneth Nielsen

Accepted

The decision tree has been updated to clarify that "significant" segments aretreated differently from smaller subcategories. Significant is defined in volume
1.

4560

2

4

1557

1558

See comment to decision tree for crude oil production. 'Significant' needs to be definedand it should reference specifically emissions from 'crude oil transport, refining andupgrading' (I wonder what happened to storage).

Ole-Kenneth Nielsen

Accepted

The decision tree has been updated to clarify that "significant" segments aretreated differently from smaller subcategories. Significant is defined in volume
1.

4562

2

4

1563

1564

The decision trees are actually important as Parties to the UNFCCC are forced to follow
them. I think, the authors should carefully examine all decision trees within Chapter 4 andcheck whether they reflect the intention of the authors. In this specific decision tree, thesentence 'If emissions from abandoned wells are a key category, are contributions fromabandoned wells significant' makes no sense.

Ole-Kenneth Nielsen

Accepted withmodification

Decision tree is deleted. It is assumed that decision trees on main categories (oiland gas industries) cover subcategory on abandoned wells.

4564

2

4

1762

1767

The decision to not have specific tier 1 EFs but rather letting the users pick and choose
between several options, is a fundemental break with the whole purpose of the tier system.
The default tier 1 EFs are for countries with no better data/knowledge and should
therefore be easy to use. Inventory compilers will now be able to calculate two different
tier 1 emission estimates and then having to choose one. Odds are both will be calculated
and the lower value reported. It is good that the SOD in some cases add some guidance,
e.g. for oil exploration (number of wells drilled is best), but this type of guidance should
be availble in all instances where there is currently several options for AD. It would be ashame if the authors have given up on providing clear guidance and leaves it all to theusers.

Ole-Kenneth Nielsen

Accepted withmodification

We have provided clear guidance throughout the document on what EFs to use,
based on technology and practices used in the country; we have noted that if acompiler is unaware of these then we recommend which of the EFs to choose. It
is not unreasonable to expect a compiler to make some decisions, based on theirown understanding of good practices.

4566

2

4

1829

1830

Table 4.2.3 only deals with onshore exploration, and I found no mention of offshore
exploration in the text. It would be good to include offshore exploration in the table eitherwith default EFs or with NA/NE, if emissions are either not applicable to offshore
exploration or no data are available to estimate EFs.

Ole-Kenneth Nielsen

Accepted withmodification

We now state in line 1790: “In the table below, several options for onshore
exploration emission factors are presented.” and in line 1795: “Emission
factors are available for both onshore unconventional and onshore conventionaloil exploration; offshore emission factors for exploration are not included.” In
the second column of Table 4.2.3 we also note that these are for onshore wells.

4568

2

4

2062

2063

Table 4.2.9 only deals with onshore exploration, and I found no mention of offshore
exploration in the text. It would be good to include offshore exploration in the table eitherwith default EFs or with NA/NE, if emissions are either not applicable to offshore
exploration or no data are available to estimate EFs.

Ole-Kenneth Nielsen

Accepted withmodification

We now state in line 1890: “In the table below, several options for onshore
exploration emission factors are presented.” and in line 1896: “Emission
factors are available for both onshore unconventional and onshore conventionaloil exploration; offshore emission factors for exploration are not included.” In
the second column of Table 4.2.9 we also note that these are for onshore wells.

Comment ID Volume

To lineComment

ExpertResponse

Authors note

4570

2

Chapter From line
4

2204

2205

The EFs for 'LNG: Import/Export' are they to be considered as loading/unloading EFs? It
seems that would be the terminology usually used, e.g. in the chapter on emissions fromtransport/storage of crude oil. The size of LNG terminals vary significantly, and the EF
for loading/unloading seems very high for some small terminals. It would be helpful withinformation on the average size of the terminals from which the default EFs have been
derived.

Ole-Kenneth Nielsen

Accepted withmodification

Yes, LNG Import/Export is synonymous with LNG loading/unloading, in asense. Information on the size of the terminals used to quantify the EFs from the
US GHGRP can be found here in Table 5:https://www.epa.gov/sites/production/files/201810/documents/ghgi_2018stakeholders_segment.pdf. This reference is includedin the references. And footnote (e) of Table 4.2.4I.

4572

2

4

2248

2249

The use of the classification of gas losses as low, medium or high at selected types ofnatural gas facilities as a source for a default EF for appliance losses seems questionable.
The source of the data is reported in the 2006 IPCC GL as "Adapted by the authors fromcurrently unpublished work by the International Gas Union, and based on data for a dozen
countries including Russia and Algeria.". This is hardly a solid reference as it isunpublished, not peer-reviewed and impossible for users to analyse and hence assess theapplicability at a wider scale. Residential natural gas boilers are usually placed indoors andwith odorant being added to the natural gas any leakages would be detected and repaired,
which makes it unlikely that leaks of the magnitude suggested would occur. If including adefault EF the scientific basis should be better than what is currently the case. The
appropriateness of the EFs should be reassessed and if proper data are not available nodefault emission factor should be provided. The same concern applies to the EF suggested
for large-scale users. The use of the value for 'rest of the world' from an obsolete versionof the IPCC GL should not be considered sufficiently scientifically robust to form thebasis of a default EF. To simply base default EFs on old unpublished studies from morethan 20 years ago is bad scientific practice and it should not be accepted by the IPCC, if
the credibility of the IPCC guidelines is to be preserved.

Ole-Kenneth Nielsen

Rejected

Meanwhile the IGU study was published - however, the values provided in therefinement compare to a recent Californian study(https://pubs.acs.org/doi/10.1021/acs.est.8b03217) and also match with theguidance of the German Technical and Scientific Association for Gas andWater (DVGW) that allows a maximum of 0 - 1 liter per hour during leak test.
The Californian study was published after the literature cut-off date and cannot
be used for the refinement. The values from the DVGW can be found inworking sheet G600 but unfortunately, it is not cost-less available and not inEnglish. Hence, it was not accepted as literature for the guidelines.

4574

2

4

2248

2249

It is not clear whether the EF for natural gas vehicles covers emissions from the wholechain, i.e. storage at filling stations, the refuelling of vehicles and emissions from vehicle
tanks. This should be specified.

Ole-Kenneth Nielsen

Accepted

Clarification has been provided.

4586

2

4

3138

3139

Since the reporting requirements are to report emissions from venting, flaring and fugitive
loses separately, this annex is very important. The authors should dedicate themselves toproperly check this annex. While some errors have been corrected between the FOD and
SOD, there are still very strange splits that if maintained at least should be explained. E.g.
one would always expect CO2 and N2O to predominately stem from flaring, while CH4
usually will be dominated by leaks and venting. With that in mind the following splits
seem to require further information: Offshore oil production (99 % of CO2 and N2O
listed as coming from venting!), Oil sands mining (suddenly decimals on the split - does
not in all cases sum to 100 %)Ole-Kenneth Nielsen

Accepted

Rechecked annex and made edits.

4588

2

4

3141

3142

What types of leaks are considered that would account for 55 % of the CO2? Also data for
NMVOC and N2O should be provided as there is a defualt emission factor included in thechapter.

Ole-Kenneth Nielsen

Accepted withmodification

Correction made to leak % for CO2 (change from 45% to 55%). Calcination is
the main process contributing CO2 emissions from leaks. Values for NMVOC
and N2O added.

4590

2

4

3144

3145

Several instances, where the percentages does not sum to 100. I have the suspicion that theN2O shares have simply been taken from the CO2. It is difficult to envision how N2O
would be released from leaks/vents in oil production. It would normally be assumed thatN2O comes from flaring. This should be checked through all tables. That 99 % of CO2
and N2O from offshore production should be from vents seems incorrect, especially sinceno CH4 is presumeaably coming from vents. CH4 and NMVOC splits sum to 105 % forgas processing with LDAR. NMVOC and N2O for acid gas removal should be 100 % as
default EFs are provided.

Ole-Kenneth Nielsen

Accepted

Throughout, I changed all N2O to 100% from flaring.
Offshore has been updated. Typo in processing has been corrected. NMVOC
and N2O for acid gas removal have been corrected.

Comment ID Volume

To lineComment

ExpertResponse

4592

2

Chapter From line
4

3148

3149

Gas storage is missing from this table and should be included to match table 4.2.12 in themain chapter. Flaring is typically more common in connetion with gas storage whereas forgas transmission flaring is usually very small to non-existing. It would also be good if
assumptions could be provided for LNG.

Ole-Kenneth Nielsen

Accepted

I added the splits for storage and for LNG to the annex.

Authors note

4596

2

4

1349

1349

The chapter is updated to reflect town gas and biogas, but the chapter name is "…natural
gas…". It should be decided if natural gas should be replaced throughout the chapter
except at places where it refers only to natural gas.

Ole-Kenneth Nielsen

Rejected

During the IPCC Scoping Meeting, in which the terms of reference and thetable of contents for the 2019 Refinement were drafted, this issue was discussed
and it was decided to keep the original denomination in the 2006 IPCC
guidelines.

4598

2

4

1395

1395

What does incineration refer to when it is not flaring and not incineration with energy
production, which belongs in the stationary or mobile combustion sector?

Ole-Kenneth Nielsen

Accepted

We deleted "incineration" from the grayed out sentence.

4600

2

4

1443

1443

(e)Distribution refer to Fugitive emissions from natural gas appiances, but should be gas
appliances to include e.g. town gas and biogas appliances.

Ole-Kenneth Nielsen

Accepted

Removed the word "natural" in the graphic.

4602

2

4

1557

1557

The first step in the diagram should be deleted ("Is there oil transport, upgrading, refining
or product distribution in the contry"), as this is unnecessary and corresponding steps are
not included in the other decision trees.

Ole-Kenneth Nielsen

Accepted

The decision tree has been updated with clearer text and to be consistent acrosssegments.

4604

2

4

1575

1575

Non-key should be changed to not-significant cf. Figure 4.2.5 ("If emissions fromabandoned wells are key category, are contributions from abandonned wells significant?" "No" - "Estimate emissions using a Tier 1 approach")

Ole-Kenneth Nielsen

Accepted withmodification

Decision tree is deleted. It is assumed that decision trees on main categories (oiland gas industries) cover subcategory on abandoned wells.

4606

2

4

1829

1829

Table 4.2.3 are missing EF for offshore exploration. All EFs refer to onshore wells

Ole-Kenneth Nielsen

Accepted withmodification

We now state in line 1790: “In the table below, several options for onshore
exploration emission factors are presented.” and in line 1795: “Emission
factors are available for both onshore unconventional and onshore conventionaloil exploration; offshore emission factors are not included.” In the second
column of Table 4.2.3 we also note that these are for onshore wells.

4608

2

4

1862

1864

What is the reasoning behind the statement "If no data are available to estimate the shareof onshore versus offshore production, EF for onshore production should be" applied tothe total quantity of oil production."

Ole-Kenneth Nielsen

Rejected

This was done to provide a default approach in the case that a compiler lacks
data on the split of production that occurs offshore versus onshore.

4610

2

4

1909

1909

The EFs for offshore oil production show a very large increase (more than a factor 1000)
compared to the IPCC 2006 GL. Is this correct or could there be there be some unit error?

Ole-Kenneth Nielsen

Rejected

The 2019 EFs were developed from reported data from the Gulf of Mexico. It
is not possible to do a detailed comparison with the 2006 GL factors as noreference is provided (e.g., we can't determine if offshore conditions aredifferent between the two data sets, or if any unit error was made in the 2006
data set).

4612

2

4

1945

1945

According to the note to Table 4.2.6 ("…. The factors include fugitive equipment leaks,
flaring, storage, handling, calcination and anode production." ) the EFs include emissions
from flaring, but these emissions should be reported under 1B2c. Including flaring in theemission factor for oil refining can cause double counting of emissions for Parties
wstimating emissins from flaring using higher Tier methods. Including the disaggregatedEFs from Annex 4A.2 in the EF table could solve this issue

Ole-Kenneth Nielsen

Rejected

Emissions from flaring have to be integrated into the appropriate segment (1 B
2 a and b). Not 1 B 2 c.

4614

2

4

1948

1948

Flaring should not be included in 1B2av as stated in the text, but in 1B2c

Ole-Kenneth Nielsen

Accepted withmodification

See comment No. 7544; basically no flaring activities in distributions of oil
products.

Comment ID Volume

To lineComment

ExpertResponse

Authors note

4616

2

Chapter From line
4

1965

1965

EFs in Table 4.2.7 refer to unabated distribution. Guidelines for distribution withabatement is missing. Further the note to the table states that emissions are temperaturedependent, but guidelines for this is missing.

Ole-Kenneth Nielsen

Accepted withmodification

We added a sentence in the footnote of table 4.2.7: "Several techniques likevapour-balancing and vapour-recovery along with use of automatic monitoring
systems will have a significant influence of the factor, in which case countryspecific Efs should be developed to reflect reduction efficiency and level ofapplicaiton of such techniques."
Insufficient data are available to provide default EFs for abatement, or further
guidance on temperature impacts.

4618

2

4

2022

2022

The text states that this segment (exploration) includes flaring, which should be reported in
1B2c

Ole-Kenneth Nielsen

Accepted withmodification“This segment includes fugitive emissions (equipment leaks, venting andflaring) …”. Flaring is part of 1 B 2 a and b. Not 1 B 2 c.

4620

2

4

2062

2063

Table 4.2.9 is missing EFs for offshore gas extraction.

Ole-Kenneth Nielsen

Accepted withmodification

We now state in line 1890: “In the table below, several options for onshore
exploration emission factors are presented.” and in line 1896: “Emission
factors are available for both onshore unconventional and onshore conventionaloil exploration; offshore emission factors for exploration are not included.” In
the second column of Table 4.2.9 we also note that these are for onshore wells.

4622

2

4

2065

2065

The text statates that this segment (exploration) includes flaring, which should be reported
in 1B2cOle-Kenneth Nielsen

Rejected

We're recommending that flaring be included in the segments where it occurs.

4624

2

4

2076

2078

The guidelines should include uniqe tier 1 methodology and corresponding set of EFs.
Now the guidebook provides two sets of EFs based on different AD, and leave it up to theinventory compilers to assess which EFs reflect the countrys emissions . No guidance isprovided for this assessment, and it is not clear what the parties should report if
information are not available to make the necessary assessment of the calculaed emissions.
The Tier 1 methodololy should include only oen set of EFs per source.

Ole-Kenneth Nielsen

Rejected

Previously, the guidelines disaggregated emissions from “developing” and“developed” countries, leaving it to the inventory compiler to decide which
category was appropriate. However, the 2019 Refinement acknowledges thatthe true discriminant should be technology/practice based, as this is the more
important determinant of emissions since the oil and gas industry can be quite
sophisticated, even in developing countries. The guidelines do suggest to theinventory compiler the best practices for selecting EFs based on available
activity data and known technologies or practices used in country.

4626

2

4

2098

2099

What is the reasoning behind the statement "If no data are available to estimate the shareof onshore versus offshore production, EF for onshore production should be" applied tothe total quantity of oil production."

Ole-Kenneth Nielsen

NotedThis was done to provide a default approach in the case that a compiler lacks
data on the split of production that occurs offshore versus onshore.

4628

2

4

2100

2102

Venting and flaring shall be reported in 1B2c. This induce parties to either make double
counting of emissions from flaring or underestimate (leave out) emissions from production
as guidance including EFs are not included in the 2019 refinement. Including thedisaggregated EFs from Annex 4A.2 in the EF table could solve this issue

Ole-Kenneth Nielsen

Rejected

The BOX 4A.2.1 already guides users how to developed disaggregated Efs byusing overall EF and disaggregated fraction.

4630

2

4

2102

2102

"disaggregated Tier 1 EF are available in Annex 4A.2". Why are these not included in themain chapter? At least the EFs should be disaggregated to the level of the CRF tables.

Ole-Kenneth Nielsen

Rejected

Adding the disaggregation option to the main body unreasonably lengthens the
text. Further, in the updates, emissions are reported in the segment where theyoccur.

4632

2

4

2116

2116

It is noticed that the EFs for offshore gas production has increase compared to the IPCC
2006 GL, and has exceeded the upper limit.

Ole-Kenneth Nielsen

Noted

The 2019 EFs are developed from a large data set from the Gulf of Mexico. It is
not possible to do a detailed comparison with the 2006 GL factors as noreference is provided (e.g., we can't determine if offshore conditions aredifferent between the two data sets, or if any unit error was made in the 2006
data set).

4634

2

4

2146

2146

In Denmark, town gas is a mixture of natural gas and ambient air (mix ~ 51/49) sinec
2007. before that town gas was based on oil and even earlier on coal.

Ole-Kenneth Nielsen

Rejected

The guidelines provide a default if no national data is available -if this differs ina country it is good practice to develop an country specific EF

Comment ID Volume

To lineComment

ExpertResponse4636

2

Chapter From line
4

2192

2193

Disaggregated EFs for storage is not included in Annex 4A.2, so parties that have country
specific calculations of fugitive emissions from transmission are missing guidance for
estimating emissions form storage.

Ole-Kenneth Nielsen

Accepted withmodification

Authors note

4638

2

4

2248

2248

EFs for towngas are only applicable for the town gas type described in l. 2146. In denmark
the EFs will be 51% of EF for natural gas.

Ole-Kenneth Nielsen

Rejected

The GL provide a default - if national circumstances differ it is good practice to
use CS EF and a higher tier.

7438

2

4

2146

2152

in first two sentences, town gas production is refered to hydrogen chapter. In following
sentences it is refered to table 4.2.11 - I guess sour gas is meant in the text.

Jens Reichel

Accepted

Changed

7440

2

4

2153

2157

processing of town gas is not part of the chapter - please correct equation

Jens Reichel

Accepted

Changed

7442

2

4

2206

2249

End-Use emissions should not be aggregated with emissions from operations of natural
gas systems. To improve transparency, those emissions should be reported in a seperate
subcategory.

Jens Reichel

Accepted

Changed

7448

2

4

1931

1931

asphalt blowing has been part of the industry chapter 2.D.3.g in previous GL - pleasedelete here

Jens Reichel

Rejected

The IPPU section 5.4.1 is explicit that asphalt production in refineries is
excluded from the scope of reporting in IPPU, whilst the new Energy - fugitives
section 4.2.2.3 for 1B2aiv also explicitly states that emissions from asphalt
blowing in refineries are included there. The authors consider that this is clear,
unambiguous guidance on best practice for reporting of emissions from asphalt
production.

7456

2

4

2235

2235

there is no disaggregated emission factors by pipeline material available in Annex 4.A.2.

Jens Reichel

Accepted withmodification

The reference has been deleted. To see the disaggregated emission factors go
the the German NIR 2017 in chapter 3.3.2.2.5.1.

7460

2

4

1951

1951

take " Vol 3 chapter 3 " instead of CRF code

Jens Reichel

Accepted

Changed

7464

2

4

1925

1925

Pipelines: If a transport pipeline runs through three countries and none of them takes evena drop of the oil transported, all countries report the same emission when using theemission factor provided. In this case the emission reported would be three times higher
then if the same pipline is located in one country. I see a problem for the EU to have toreport very high emission. Is is possible to provide a factor in tons per kilometer pipeline?

Jens Reichel

Rejected

The EF provided was adopted from the 2006 GL . To avoid an overestimation
it is recommended to use a higher tier.

7544

2

4

1787

2265

In description of most subcategories of oil (i.e. 1 B 2 a i Exploration, 1 B 2 a ii Production
and Upgrading, 1 B 2 a iii Transport, 1 B 2 a iv Refining, 1 B 2 a v Distribution of Oil
Products, 1 B 2 a vi Other) and gas systems (1 B 2 b i Exploration, 1 B 2 b ii Production
and Gathering, 1 B 2 b iii Processing, 1 B 2 b iv Transmission and Storage, 1 B 2 b v
Distribution, 1 B 2 b vi Other) it is written that segment includes fugitive emissions,
including leaks, venting and flaring (e.g. Line 1833). In the last guidelines was written thatemissions excluding venting and flaring. We are not sure that venting and flaring in factoccur in all subcategories of oil and gas systems. And for instance, in description of
subcategory 1 B 2 a iii Transport, it is not further mentioned if the default emission factors
are inclusive of venting, flaring and leaks or not, which could cause misunderstanding.
This same issue is in other subcategories as well.

Eva Krtkova

AcceptedLine 1912: leaks and venting (oil transport);
Line 1948: leaks and venting (distribution of oil products);
Line 2207: leaks, venting and any flaring (gas distribution);

Disaggregated EFs for gas storage have been provided in Annex.

Disaggregation for oil and gas exploration and gas storage and LNG added tothe annex.

Comment ID Volume

To lineComment

ExpertResponse

Authors note

7822

2

Chapter From line
4

1443

1444

It is unclear what "Offshore Gas Liquefaction" (LNG) means in the figure. Mostliquefaction plants are included onshore. Further, LNG liquefaction occurs after
Transmisson. Similarly on the destination point, the regasification terminal receives the
LNG and then the natural gas into the transmission systems. Recommend that IPCC revise
the supply chain framework with consultation with industry.

FIJI GEORGE

Accepted withmodification

LNG is only mentioned in 1B 2b iv in the text, so we remove any wording about
it under the Processing column. We alter the wording under Transmission andStorage to read “LNG Stations and Export/Import Terminals (Liquefaction, Regasification), Transport & Storage.” We connect this with a green arrow to the
LNG truck and ship to represent transportation. Under the onshore plant next
to the underground storage we now state: “LNG Stations and Export/Importterminals (Liquefaction, Re-gasification), transport, and storage”. The boatnext to it has the listing LNG transport (and obviously represents shipping). In
the caption for the figure we now note: “Note: this diagram provides examplesof activities included in the segments of oil systems; it is not intended as a flow
chart or supply chain diagram.”
It is out of scope to “revise the supply chain framework with consultation withindustry.”

7824

2

4

1443

1444

Fugitive emissions from natural gas appliances (e.g. internal pipes and applicances likestoves, dryers, heaters, grills) are illustrated in Figure 4.2.1. Emissions from end-use
should be listed separately under "additional" or within each specific end-use sector(residential/commercial OR power OR industrial) with a clear listing that these aremethane emissions.

FIJI GEORGE

Accepted withmodification

These emissions are in scope of natural gas systems, and were moved from
Distribution systems to a new group, "Post-meter emissions."

7826

2

4

1546

1547

Figure 4.2.2 is applicable for natural gas systems, but as cited in the comments above,
LNG systems has a different pathway and profile.

FIJI GEORGE

Accepted withmodification

We have modified the figure to add additional features of the LNG profile. See
response to comment #7822.

7828

2

4

1613

1614

Table 4.2.1: LNG systems should not be "lumped" with Gas Transmission. The
International Energy Agency (IEA) World Energy Outlook 2017 (WEO) projects theglobaldemand for natural gas will see a compounded average annual growth rate of 0.6-1.9% in
the timeframe of 2016-2040, with LNG provided a significant portion of this growth. It is
technically and functionally incorrect to mix LNG liquefaction and regasificaiton facilities
with Gas transmission systems. Completely different processes. Recommend IPCC
develop a separate industry segment in light of future projections on LNG demand withindustry before the 2019 Refinements are finalized.

FIJI GEORGE

Noted

It is out of scope to develop an additional segment at this time. Of importanceto the guidelines is that all fugitive emissions be captured. Within theframework of the 2019 Refinement, we retain LNG (i.e. its liquefaction,
regasification, and transmission) as part of Natural Gas Systems category 1 B
2b iv as described in the text.

7830

2

4

1615

1721

Consider application of the latest reserch from Stanford (Separately consider the CO2
aspects in the other chapter)- Masnadi et al. for Tier 2 factors.

FIJI GEORGE

Noted

No action can be taken because comment is out of scope of 2019 Refinement.
1) The reference is more about GHG projection, not GHG estimation for aparticular year;2) The age distribution of the oil wells is not avaiable in many countries.
3) The mandate is to develop Tier 1 Efs.

7832

2

4

1980

2019

It appears that the IPCC is relying on a very small subset and based in US and UK todevelop the emission factors. The IPCC should first consider are these material emissions
and review the methods by Kang et al and Townsend-Small as being representative. Withhuge uncertainty ranges included in Table 4.2.8, is it worth to incorporate this source
category into the the 2019 refinement?

FIJI GEORGE

Rejected

A number of data sources were reviewed for abandoned wells, each confirmingthat abandoned wells is a sizable emissions source. The studies also foundsimilar rates of emissions for abandoned wells. The EFs presented come froma large number of measurements and are appropriate tier 1 factors.

7834

2

4

2082

2086

It is incorrect to state that liquids unloadings with plunger lifts is a lower emitting
technology than manual unloadings. There are multiple factors that go into unloadings
and while on a unit-basis, plunger lifts may have lower emissions, it is not necessarily true
on a total cummulative basis. Further, plunger lifts are merely ONE form of artificial lifts.
Gas lifts and other techniques also serve the same purpose. Finally, failure of plungers andother artificial techniqes cause these sources to behave like manual unloadings. Please see
Schwietzke et al (2016), where over 50 unloadings were classifed as manual, when in factmany were due to failures of the artificial lift system which caused these wells to behave
like manual unloadings.

FIJI GEORGE

Accepted withmodification

Edited text.

Comment ID Volume

To lineComment

ExpertResponse

Authors note

7836

2

Chapter From line
4

2116

2117

Table 4.2.10: Footnotes a and b cite the 1996 GRI study. The National Academies of
Sciences in the US have reviewed this extensively and called out many improvements toemission factors. As one of the authors of that study, I urge the IPCC to reconsider theuse of outdated factors. Table 4.2.10, footnote d references emission factors previously
developed for gas storage facilities. The Department of Energy has commissioned a study
that will provide methane emission factors specific to gathering and boosting stations foruse in greenhouse gas inventories. The study will also review episodic events.

FIJI GEORGE

Rejected

GRI factors are used primarily for early years 1990's of US time series, and we
think represent practices then, and practice without mitigation. For recent years,
better data can be used to caculate emisisons and we've done that and it's in theEFs presented here in many cases. Footnote d refers to Marchese, whichmeasured gathering stations specifically, and to GRI for blowdown emissions(data unavailable specific to gathering). The DOE study mentioned here is notavailable yet.

7838

2

4

2116

2117

Footnote d for Gathering refers to Marchese et al. Please refer to recent studies by
Vaughn et al (2017) published in Journal Elementa (gathering and boosting stations. ElemSci Anth. 2017;5:71. DOI: http://doi.org/10.1525/elementa.257 ) and Vaughn et al (2018approved for publication in PNAS). There are other studies in the works funded by the US
Department of Energy that will be soon released. These two independent studies are being
conducted by Colorado State University (Dan Zimmerle) and GSI Environmental Inc.
(Ann Smith-PI - https://www.netl.doe.gov/research/oil-and-gas/project-summaries/naturalgas-midstream-projects/fe0029085-gsi and https://www.netl.doe.gov/research/oil-andgas/project-summaries/natural-gas-midstream-projects/fe0029084-gsi). These will
provide a significantly larger data set and avoid the limited data from the Marchese et al
study.

FIJI GEORGE

Rejected

The footnote refers to references used in the EFs presented in the table. The
studies noted in the comment were not used in the EFs. The Vaughn study
showed higher emissions than the Marchese study, while other studies showed
lower emissions (Yacovitch et al 2017 and US EPA GHGRP data). The DOE
studies have not been published yet and therefore cannot be considered.

7840

2

4

2064

2109

The application of LDAR voluntarily or regulatory is now a growing practice in the US
and elsewhere. The efficacy of LDAR has been illustrated in many regulatory programs
and papers (Ravikumar, A. et al (2017, 2018), George, F. (2018- World Gas ConferenceSee Tables S1-S4)

FIJI GEORGE

Accepted

Included in description of lower emitting technologies.

7842

2

4

2126

2130

"Where this information is unknown, or where there are limited or no LDAR programs,
the “without LDAR, less than 50% of centrifugal compressors are dry seal” emission
factors for Gas Processing should be used. What is the basis of this information? It would
be more appropriate to go with the vintage of the compressors. Dry seals are now
standard for most aero-deravative compressors.

FIJI GEORGE

Rejected

We don't have information on vintage of compressors. I think it's okay that dry
seals are now standard. The wet seal EF can be used for years when it's notstandard.

7844

2

4

2158

2159

Table 4.2.11. Contrary to National Academies of Sciences' advise, the SOD once again
recommends using outdated emission factors from the 1996 GRI study. There are
multiple new studies that are out there and highly recommend IPCC consider them. Also
as noted above, the basis of using LDAR as proxy for dry and wet-seals seems to bewithout merit. At a minimum, the basis for this guesstimate should be provided. In myabout 25 years with the industry, I have not seen or understand this.

FIJI GEORGE

Accepted withmodification

1) Agree that there are new studies on which the factors for low-emitting
technologies are based. However, the higher emitting practices/technologies
which are still used widerly are still best represented by the 1996 report.
2) The relationship between LDAR and dry-wet seals has been further clarified
in both text and table 4.2.11.

7846

2

4

2170

2172

LNG import and export terminals should NOT be included in the Transmission andStorage sector. Rather as noted on Row 13 and 16 of these comments, they should be
separate source category. Also see MARCOGAZ 2018 (SURVEY METHANEEMISSIONS FOR LNG TERMINALS IN EUROPE). And also see GHGRP foremissions from Cheniere's Sabine Pass Liquefaction terminal and other US operators (seeexcel spreadsheet)

FIJI GEORGE

Rejected

Import/export terminals are part of Transmission and Storage per 2006
guidelines. It is out of scope to take LNG Import/Export terminal emissions out
of 1B 2 b iv.

7848

2

4

2205

2205

Table 4.2.12: What is the basis for emission factors with and without higher emitting
technologies or practices. Neither the GHGRP or Zimmerle (2016) provides the
granularity to assess the efficacy of LDAR. There are multiple papers that will be out
soon. And the assumption of 40, 60 and 80% reductions by LDAR is a incorrect (Seeincorrect basis and errors in the assumptions - see George et al 2018 (World Gas
Conference))

FIJI GEORGE

Accepted withmodification

Added text to clarify where the factors are from. we're not using an assumptionof 40/60/80, we're just using more recent years of data, when LDAR is used, toshow lower emitting technologies, and older data to show higher emitting
technologies.

7850

2

4

2432

2456

The National Academies provides advise on issues with time-series look-backs. Highly
recommend IPCC committee to review recommendations of the US National Academiesof Sciences

FIJI GEORGE

Rejected

Out of scope of Energy volume.

Comment ID Volume

To lineComment

ExpertResponse

Authors note

7852

2

Chapter From line
4

1530

1530

Variability of methane emissions measurements and over time is addressed in multiple
studies especially Vaughn et al (PNAS, 2018). The influence of episodic events(unloadings, flowbacks and maintenance) versus malfunctions versus routine operations
should be clearly understood. In fact, Tier 3 level estimation should incorporate theserecommendations (see NAS recommendations) to develop a better estimate of emissions.
The role of super emitters should NOT be incorrectly attributed based on a skewed
statistical model. Additionally for compressor sites in a study completed for the DOE by
GSI Environmental Inc.. The TFI team should review these studies to address thevariability concerns.

FIJI GEORGE

Rejected

Tier 3 is out of scope. Furthemore, DOE/GSI studies are not yet published andtherefore cannot be considered.

7854

2

4

1613

1614

Should marginal (or low producing) gas and oil wells be included on Table 4.2.1? There
have been conflicting studies that assess the impacts of marginal wells. Regardless the
TFI may want to consider disaggregating marginal wells and non-marginal wells anddevelop appropriate emission factors in (kg/MCF or cu.m).

FIJI GEORGE

Rejected

As the commenter notes, there are conflicting studies on marginal wells. The
estimates would likely become much more uncertain by disaggregating EFs andalso disaggregating activity data (most countries will not have data to split wells
between marginal and non-marginal).

7856

2

4

2204

2205

Table 4.2.12, footnote d references emission factors previously developed for gas storage
facilities. The Department of Energy has commissioned two studies that will provide
methane emission factors specific to different types of gas storage wells to support
development of more accurate facility-wide values using well counts and account forcontinuous capture of diurnal to seasonal variability of emissions from entire facilities withcomponent-level resolution (e.g. specific compressor, sealed well head, etc. emissions
rates).

FIJI GEORGE

Rejected

The DOE study is not published yet and cannot be assessed for this work.

7858

2

4

2385

2386

The statement "consistent terminology and clear definitions is critical in developing countsof facilities and equipment components" underscores the need for such terminology anddefinitions to be standardized. The Final Report for a current study being performed forthe DOE by GSI Environmental Inc. provides a good example of objective guidelines forcomponent counting and classification.

FIJI GEORGE

Noted

Referenced document is not published by required date

7860

2

4

2459

2460

The TFI is requested to review the recommendations of the National Academies. Further,
the DOE has funded a study evaluating uncertainty associated with several accepted
methane measurement technologies is in the process of being developed .

FIJI GEORGE

Accepted

The DOE studies have not yet been published so they cannot be considered. To
address the NAS recommendation portion of the comment, we added "including
whether the measurements capture any high-emitting subpopulations (e.g.,
malfunctions) and episodic sources and whether these have been incorporated
into the average factors in a way that does not over- or under-estimate total
emissions" to the emission factor uncertainty section. The NAS
recommendations aren't really relevant to Tier 1 approaches, so not clear that a
lot of it is in scope. Other NAS recommendations on uncertainty (e.g.
importance of activity data) are already captured.

8358

2

4

1365

1366

Fugitive emissions from appliances should not be included as part of emissions from oiland natural gas systems

Miriam Levon

Rejected

Clarification added to the text that emissions occuring between gasmeters andappliances are covered by 1.B.2.b.vi while emissions from the appliances
themselve (start-stop losses plus combustion) are not covered by themethodology.

8360

2

4

1443

1445

In Figure 4.2.1: Fugitive emissions from natural gas appliances (e.g. internal pipes andapplicances like stoves, dryers, heaters,
grills), should be removed from the depiction of emissions from natural gas systems.
These emissions are attributable to the use of natural gas in residential or commercial
settings.

Miriam Levon

Rejected

These emissions are in scope of natural gas systems, and were moved from
Distribution systems to a new group, "Post-meter emissions."

Comment ID Volume

ExpertResponse

Authors note

8362

2

Chapter From line
4

1790

To line1829

The table cited (Table 4.2.3) does not provide emission factors for offshore oil
exploration. If the intent is for the emission factors to be used for both onshore andoffshore exploraion, the text and the table should clearly note that.

Comment

Miriam Levon

Accepted

We now state in line 1790: “In the table below, several options for onshore
exploration emission factors are presented.” and in line 1795: “Emission
factors are available for both onshore unconventional and onshore conventionaloil exploration; offshore emission factors for exploration are not included.” In
the second column of Table 4.2.3 we also note that these are for onshore wells.

8364

2

4

1829

1830

Footnote (a) stipulates that, "factor is an average of 2003-2007 calculated impliedemission factors for emissions from well drilling, well testing, and from well completions
with hydraulic fracturing that do not flare or use gas capture". It is not clear why thefactors provided are based on an average of 2003-2007 calendar years data.

Miriam Levon

Accepted

Added "The time period of 2003-2007 was selected as it represents a time when
hydraulic fracturing is occurring, but before state or federal regulations were inplace to control gas emis-sions. "

8366

2

4

1861

1864

Need to clarify whether emission calculations for oil production from oil sands should use
the EFs for 'Oil Sands Mining and Ore Processing' or 'Oil Sand Upgrading' in addition to or in lieu of - the other EFs provided for oil production.

Miriam Levon

Rejected

It has clearly mentioned that "production of oil sands is treated separately".

8368

2

4

1999

2000

The EF provided for abandoned wells have very high uncertainty bounds making it
questionable why this emission source should be accounted for here. The information onwhich these EFs are based is sparse and limited in scope and its inclusion in GHG
inventories should be deferred until more robust data is available

Miriam Levon

Rejected

Following Report of IPCC Scoping Meeting for a Methodology Report(s) to
refine the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, thecategory was considered for inclusion in the Guidelines. We disagree thatavailable data is sparse and limited in scope. A number of studies of abandoned
wells in the U.S., U.K. and the North Sea were reviewed, and showedcomparable average emission factors. The Townsend Small et al study was
selected to develop the EFs for onshore wells as it allowed for emission factors
distinguished by plugged and unplugged status.

8370

2

4

2006

2007

The citation provided in footnote (b) of Table 4.2.8 references Vielstädte et al. (2015).
That study indicates that "direct methane transport into the atmosphere was found to be
negligible (<2%) due to the small bubble sizes and the water depth at which they are
released." This is NOT consistent with the text that specifies that 80% of the methane
emitted from offshore abandoned wells is dissolved in marine water.

Miriam Levon

Accepted

This is a misprint. 80% is replaced with 98%. The calculations of EFs arecorrect and consistent with the relevant text.

8372

2

4

2050

2053

The text and the referenced table (Table 4.2.9) do not provide a distinction between
onshore and offshore natural gas exploration. If the intent is that the same Efs areapplicable for onshore and offshore exploration than the text should clarify this to theusers.

Miriam Levon

Accepted

Edited text to say: Offshore exploration emissions data are unavailable, andthese emissions are thought to be negligible; there-fore, emission factors are notincluded for offshore exploration.

8374

2

4

2116

2117

The emission factors for gathering in Table 4.2.10 are based on outdated data which tend
to underestimate emissions from this segment. The entries should be amended to reflect
the latest data available directly from the U.S. GHGRP. It is important to emphasize
emissions from compressor engines which a significant source for gathering and boosting
operations. Also, in footnote (d) the use of data from Marchese et. al. 2015 is notapplicable for global Tier 1 EFs for gathering. Marchese data is hardly representative ofU.S. gathering operations and should not be extrapolated globally.

Miriam Levon

Rejected

1) The contribution of compressor engines has been mentioned in line 2071;
2) In order not underestimate emission by using Tier 1 EFs, the Marchese study
was used instead of GHGRP data whoes emission rates LOWER than the
Marchese sutdy. So if Marchese underestimates, using GHGRP would makethe issue worse.
3) The combination of the old data and new data could reflect the real situation
better than one set of data.

8376

2

4

2147

2158

Town gas processing is discussed in the text and Eq.4.2.15 requires the use of thecorresponding EF, if such processing is practiced in the country. However, the EF for
town gas processing is not provided in Table 4.2.11. Please amend.

Miriam Levon

Accepted withmodification

8378

2

4

2224

2225

Fugitive emissions from appliances and power plant (post meter) should not be included aspart of Distribution segment
fugitive emissions.

Miriam Levon

Accepted

Production of town gas should be reported under fuel transformation - theequation has been corrected.

Changed.

Comment ID Volume

To lineComment

ExpertResponse

8380

2

Chapter From line
4

2230

2235

Emissions from appliances and power plants - including leakage after gas meters - should
be reported as fugitive emissions from the respective sectors, i.e. residential, commercial
and power generation and not included here with the Distribution segment emissions.

Miriam Levon

Accepted

A new segment has been added for those emissions.

Authors note

8382

2

4

2248

2249

In Table 4.2.13 the Distribution segment EFs for 'Natural gas-fueled vehicles', 'Appliancesin commercial and residential sector', and 'Leakage at industrial plants and power stations'should NOT be included here. They should be included in the applicable chapters that
include guidance for transportation, commercial, residential, industrial and power
generation.

Miriam Levon

Accepted withmodification

A new segment has been added for those emissions.

8384

2

4

2260

2265

The lack of data indicated here is a clear manifestation that it is premature to include
emission estimates from abnadoned oil
and gas wells in national inventories untill more data becomes available.

Miriam Levon

Rejected

Following Report of IPCC Scoping Meeting for a Methodology Report(s) to
refine the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, thecategory was considered for inclusion in the Guidelines. We disagree thatavailable data is sparse and limited in scope. A number of studies of abandoned
wells in the U.S., U.K. and the North Sea were reviewed, and showedcomparable average emission factors. The Townsend Small et al study was
selected to develop the EFs for onshore wells as it allowed for emission factors
distinguished by plugged and unplugged status.

8386

2

4

3919

3919

In the references to Section 4.2 add the specific references to: (1) API GHG Methodology
Compendium (2009), (2) IPIECA/API GHG Reporting Guidleines (2011), and (3) API
LNG GHG Methodology (2015). These three citations are provided in the text but notincluded in the References list here.

Miriam Levon

Accepted

References added.

8452

2

4

1778

1784

Tier 1 methane emission factors for Oil and Natural Gas Systems (O&G) are based
primarily on data from the United States Environmental Protection Agency Greenhouse
Gas Inventory (US GHGI). Alvarez et al 2018 (paper and supplementary material attached
as Vol2_Ch4_1778_1784_172 and Vol2_Ch4_1778_1784_174) report that 2015 U.S.
O&G methane emissions based on ground-based measurements from 6 regions andvalidated with aircraft observations from 9 regions are ~60% higher than US GHGI
estimates. This disrepancy is attributed to the US GHGI excluding emissions fromabnormal or otherwise avoidable conditions that are difficult to quantify with equipmentbased measurement approaches traditionally used to develop inventories. Therefore, Tier 1
emission factors likely are biased low and their application will tend to underestimate
emissions (assuming factors only are used for sources with emission profiles similar to theUnited States). As discussed in Volume 1 Chapter 6, atmospheric measurements should be
used to improve the accuracy of inventories including the US GHGI and related data suchas the Tier 1 emission factors. To highlight this important point, I recommend citing
Alvarez et al 2018 in Volume 2 and adding the following sentence to the end of thereferenced paragraph. "The accuracy of factors is dependent on the uncertainty ofunderlying data and it is good practice to verify and update factors as new data become
available".

David Lyon

Accepted withmodification

The suggested language was edited so that it is addressing inventory compilers,and added to the text. "In addition, the accuracy of factors is dependent on theuncertainty of underlying data. A country should periodically assess changes intechnologies and practices, and changes in available emissions data, andconsider updating estimates using at least a Tier 2 approach, per good practice."

8456

2

4

1387

1389

Could you specify or examine more details about "country's circumstance" effecting on the
fugitive emissions?

Pornphimol
Winyuchakrit

Accepted

Edited to say "will vary according to the amount of oil and gas produced,
consumed, imported and exported, and according to technolgies and practices
in place in different segments that may increase or decrease emissions"

8716

2

4

1434

1438

Suggestion for a tiny modification. In the exploration and production elements of thecharts (lower part) one could add a little flare on each of the towers as these are alwys
there in real life (or maybe they are there but very small?) o.

Zbigniew Klimont

Accepted

Added.

Comment ID Volume

To lineComment

ExpertResponse

8718

2

Chapter From line
4

1830

1830

I wonder if the recently publised data in the Science paper on the US underestimation of
methane from US oil and gas systems has been considered. I see in the text the ref to EPA
only.

Zbigniew Klimont

Accepted withmodification

Authors note

8720

2

4

1830

1830

Table 4.2.3. The comment as above but another study from last year looking at loses ofmethane from oil production

Zbigniew Klimont

Accepted

See comment NO. 8452 (and 8718), a new sentence has been added to reflect
the progress of new studies.

8860

2

4

2204

Table 4.2.12 Shows Uncertainty levels for fugitive emissions in gas transmission, storage
and distribution to be -20-500%. Are there any efforts to provide leakage rates per
country? Considering types of pipelines, age, etc?

MINGMING WANG

Rejected

Identification of Tier 2 EFs (country-specific one) is out of the scope.

9002

2

4

1463

1464

Casing-head gas venting may also occur at stripper wells. Suggest changing the subject
text as follows" …. heavy oil wells and stripper wells where…..".

Picard Dave

Noted

No action can be taken because comment is out of scope of 2019 Refinement.

700

2

4

2587

2588

It is proposed that in this paragraph, the authors provide the description of fueltransformation process and identify the greenhouse gasses released during this process.

Mikhail Gitarskiy

Accepted withmodification

A definition of fuel transformation has been added under Heading 4.3. The
specific GHGs that are released in each transformation are discussed in therespective sections.

3416

2

4

2594

2596

"Fugitive emissions from the following fuel transformation activities have been included inthis section - charcoal production, coke production, other solid fuels to solid fuels, coal toliquid, gas to liquid, biomass to liquid, biomass to gas, and refineries." I can see no otherreferences to refineries in section 4.3. Are refineries actually included here?

Håkon F. Skullerud

Accepted

This Chapter does not cover this source. Cross reference has been added"refineries are considered in Chapter 4.2 in this volume."

3962

2

4

2598

Table 4.3.1, fourth column, please add references

Andrea TILCHE

Accepted withmodification

Column has been removed to simplify the table.

6142

2

4

2598

2599

I suggest that the authors replace "[add reference]" by "Chapters 1 and 2 of this Volume"
under the fourth column of Table 4.3.1.

Naofumi Kosaka

Accepted withmodification

Column has been removed to simplify the table.

2904

2

4

2607

2608

Verify bibliographic citation format

Poot-Delgado Carlos
Antonio

Accepted

2906

2

4

2611

2611

Verify bibliographic citation format

Poot-Delgado Carlos
Antonio

Accepted withmodification

1960

2

4

2626

2626

An error was found in the Figure 4.3.1. For countries where charcoal production is a key
category, the arrow should start from the rhombus, not from the rectangle.

DONGKOO KIM

Accepted

An arrow has been inserted from rhombus instead of the rectangular.

702

2

4

2626

2627

The decision tree in Figure 4.3.1 is inconsistent with the concept of inventory preparationand improvement, which builds upon key category analysis, as outlined in Volume 1 ofthe2006 Guidelines. In the 2006 Guidelines, the question if the category concerned is key
stands in the beginning of the decision tree and guides further actions by the inventory
compilers. To maintain concictency with general guidance in Volume 1 of the 2006
Guidelines, it is proposed that the authors reconcile the oder of questions in the decision
tree to move the key category identification on top of it.

Mikhail Gitarskiy

Accepted

The question on key category is at the end in practically almost all decision
trees in the energy volume. Therefore this decision tree is in line with almost all
decision trees in volume 2.

1992

2

4

2626

2627

In Figure 4.3.1 Decision tree for charcoal production, the word “Yes” on the arrow line
between Diamonds box “Is national charcoal production data available?” and Diamondbox “Is charcoal production a key category?”, should be changed to “No”.

DAN YU TIAN

Accepted"NO" has been inserted down from "Is national charcoal data available" and anarrow has been inserted from rhombus instead of the rectangular.

1994

2

4

2626

2627

The arrow line approaching Square box “Collect data for higher Tiers” should originate
from Diamond box “Is charcoal production a key category?”, instead of from Square box“Tier 1. Estimate emissions using fuel data and default emission factors”.

DAN YU TIAN

Accepted

The arrow for "collecting data from for higher tiers" has been changed to tooriginate from Diamond box specifying is "charcoal produced a key category".

Addressed this through comment 8452 on the Alvarez study (adding thesentence).

Biblographical citation format done.

The sentence includes the references has been deleted in the FD.

Comment ID Volume

To lineComment

ExpertResponse

Authors note

4576

2

Chapter From line
4

2626

2627

Figure 4.3.1 needs some help. Both ways out of 'Is national charcoal production data
available' are 'Yes'. Also, apparently, the only answer to the question 'Is charcoal
production a key category' is no. While this may be accurate, there probably should be a
Yes route as well.

Ole-Kenneth Nielsen

Accepted

The arrow for "collecting data from for higher tiers" has been changed to tooriginate from Diamond box specifying is "charcoal produced a key category".

3964

2

4

2636

2639

The equal signs in the explanation for the equation need to be lined up- editors should do
this.

Andrea TILCHE

Accepted

4578

2

4

2647

2649

The default EFs is not depending on kiln type and therefore the title of the table should bechanged. The same change should be applied to the EF description in line 2638.

Ole-Kenneth Nielsen

Accepted

Text deleted.

7444

2

4

2648

2649

the chapter describes that charcoal is produced from biomass but in fact, it is quite
common to add compressed lignite briquetts to charcoal - please make clear that in thatcase, CO2 emissions should not be reported as memo item - please also provide areference where to report emissions from charcoal use (e.g. 2.G.4)

Jens Reichel

Accepted

In some cases, charcoal is produced as biomass in the form of compressedlignite as reporteed by Yaman, et al, and Chaiklangmuang, et, al but there are noemission factors provided.

2908

2

4

2648

2649

Verify bibliographic citation format

Poot-Delgado Carlos
Antonio

Accepted

7454

2

4

2649

2658

the FAO provides estimation of charcoal production of each country - would be helpful tomention this here

Jens Reichel

Accepted

Reference added for http://www.fao.org/faostat/

3966

2

4

2666

Andrea TILCHE

Accepted

Table 4.3.3 has been refereed in the text.

4580

2

4

2666

2667

The uncertainties information should be simplified to reflect that default EFs are notavailable by kiln type.

Ole-Kenneth Nielsen

Accepted

A sentence "it is noted that uncertainty range of information is irrespective ofthe type of kiln" has been added to the Table.

8722

2

4

2667

2815

The whole section about Coke has no reference to China, by far the biggest coke producer
now and in the recent decades. The suggestion for emission facors based on German study
and JRC review might be inapropriate for China; although I admit I have not checked andtried to make an essessment of plausability of this statemtn. I suggest the authors consider
this and maybe analyze a study about transformation in Chinese coke sector; see ref to theEnergy Policy paper

Zbigniew Klimont

Noted

The paper is: China’s coke industry: Recent policies, technology shift, andimplication for energy and the environment. Hong Huo et al, (2012). Energy
Policy 51 (2012) 397–404. The chapter authors have reviewed the paper andthe paper does not provide emission factors for the direct GHGs for fugitive
emissions.

6144

2

4

2671

2671

I suggest that the authors add the following text at the end of line 2671: "Please refer tosection 4.2, Volume 3 for the process emissions from metallurgical coke production."

Naofumi Kosaka

Accepted

Cross reference added to the section of the guidelines covering process
emissions.

1388

2

4

2675

2675

Edit "… 1150 - 1350 oC, indirectly…"

Robert Lanza

Accepted

Text updated.

1390

2

4

2676

2676

Edit "…reducing agent used in hot metal production…"

Robert Lanza

Accepted

Text updated.

1392

2

4

2679

2679

Edit "… in the stock column of the blast furnace."

Robert Lanza

Accepted

Text updated.

1394

2

4

2680

2681

According to IEA data (see IEA Coal Information Overview, Table 1) coking coalproduction was 1 108.7 Mt (2014); 1 081.1 Mt (2015), and 1 074.3 Mt (2016)

Robert Lanza

Accepted withmodification

1396

2

4

2680

2681

According to EIA data (see EIA Metallurgical Coke Production, World Table )Metallurgical Coke production was 750,000 short tons in 2015

Robert Lanza

Accepted

1996

2

4

2691

2702

Given that oven systems of a heat recovery coking plant differ clearly in design comparing
with a conventional coking plant, does Figure 4.3.2, along with the showing flow diagramand emission sources, apply to a heat recovery coking plant? If not, the reviewer would
suggest the authors provide another Figure to show the flow diagram and emission sourcesof a heat recovery coking plant.

DAN YU TIAN

Accepted withmodification

Table 4.3.3 seems not to be referred to in the text.

Global coke production for 2016 added.

The numbers have been updated.

The figure 4.3.2 has been revised appropriately. The process in the diagram
have been generalised, and apply to both heat recovery and not-heat recovery
plants.

Comment ID Volume

To lineComment

2910

2

Chapter From line
4

2695

2696

The text of the flow diagram is not distinguished

ExpertResponse

Poot-Delgado Carlos
Antonio

Accepted

The figure has been redrawn.

1398

2

4

2695

2696

1998

2

4

2708

2000

2

4

1400

2

3408

Authors note

Figure 4.3.2 is not entirely legible as a half-page figure; suggest making this a full-page
figure.

Robert Lanza

Accepted

The figure has been redrawn.

2709

There should be a comma or semicolon between “… a conventional coking plant” and “”
recovery of the heat of …”

DAN YU TIAN

Accepted

Sentence modified.

2709

2709

Text error, “cooking” should be “coking”

DAN YU TIAN

Accepted

Typographical error corrected.

4

2714

2714

Suggest adding flaring of coke oven gas to Table 4.3.4 as a separate line intem

Robert Lanza

Accepted

Flaring has been added to the table.

2

4

2715

2716

In Table 4.3.4, Fugitive gas emssion from "coking" production stage might be double
counting of emissions from iron and steel sector, because when emissions from cokeproduction are estimated by Carbon mass balance following the G/L in the IPPU(Vol.3,
Ch.4), it counts the total carbon in that process

Eunae Seo

Accepted

Setence added: "Inventory compilers who are using a carbon mass balance
approach to estimate emissions from the iron and steel sector, and are including
fugitive emissions in this balance, should not use the methods in this section toestimate emissions to avoid double counting."

8546

2

4

2715

2716

The meaning of "N" is not described in likelihood of fugitive emissions of TABLE 4.3.4.
"N = No"should be added.

Takuji Terakawa

AcceptedDefinition of "N" added.

6024

2

4

2715

2716

There is no indication for the notation key "N"

RENATA GRISOLI

AcceptedDefinition of "N" added.

2002

2

4

2715

2716

In Table 4.3.4, code “N” appears several times from the 3rd column to the 5th column
with no explanation for its meaning. Does N=No?

DAN YU TIAN

AcceptedDefinition of "N" added.

2004

2

4

2715

2716

In Table 4.3.4, the cell at 4th row and 7th column states that “Emissions from the fuelused to heat the coke batteries should be reported in the energy sector using themethodologies set out in the stationary combustion chapter”. Does this statement(including the methodologies set out in the stationary combustion chapter) also apply toheat recovery coke ovens? If not, the reviewer would suggest the authors to provide amethodological guidance for estimating CO2 emissions from the flue gas of a heatrecovery coke oven.

DAN YU TIAN

Noted

Yes, it does apply to heat recovery ovens. Some fuel use will be needed to start
the heat recovery coke ovens from "cold". Flue gas combustion from a heatrecovery coke oven would be estimated using the methods set out in thestationary combustion chapter.

2006

2

4

2715

2716

Texts in the cells at the 6th and 7th columns at the last row are too similar to those texts
referring to coke pushing. The reviewer understands that coking quenching may have a
different emission profile than coking pushing, as hot coke may react with water during
wet coke quenching.

DAN YU TIAN

Accepted

The text has been revised.

7564

2

4

2717

2717

In the Figure 4.3.3, there are still items “Under development”.

Coralie JEANNOT

Accepted

The decision tree has been finalised.

1962

2

4

2717

2717

An error was found in the Figure 4.3.3. For countries where coke production is a key
category, the arrow should start from the rhombus, not from the rectangle.

DONGKOO KIM

Accepted

The decision tree has been finalised.

1964

2

4

2717

2717

An typo was found in the Figure 4.3.3. The expression "Is coke production key category?"needs to be corrected as "Is coke production a key category?".

DONGKOO KIM

Accepted

The decision tree has been finalised.

3968

2

4

2717

2718

The decision tree diagram is not complete- what does "underdevelopment" mean?.

Andrea TILCHE

Accepted

The decision tree has been finalised.

1966

2

4

2717

2718

There is not enough explanation about the choice of methods in the text. Adding enoughexplanation will make readers understand the logical flow of decision tree in Figure 4.3.3.

DONGKOO KIM

Accepted

The decision tree has been finalised.

704

2

4

2717

2718

It is proposed that the authors further elaborate on the decision tree in Figure 4.3.3 toinclude the guidance on tier 1 method and fill in the bottom block.

Mikhail Gitarskiy

Accepted

The decision tree has been finalised.

Comment ID Volume

To lineComment

ExpertResponse

2008

2

Chapter From line
4

2717

2718

The arrow line approaching Square box “Collect data for higher Tiers” should originate
from Diamond box “Is coke production key category?”, instead of from the blank Squarebox.

DAN YU TIAN

Accepted

The decision tree has been finalised.

4582

2

4

2717

2718

Disappointing to have an incomplete decision tree in a SOD.

Ole-Kenneth Nielsen

Accepted

The decision tree has been finalised.

1402

2

4

2717

2728

Figure 4.3.3. is unfinished.

Robert Lanza

Accepted

The decision tree has been finalised.

1404

2

4

2727

2727

Edit "… because of the high expenitures required for …"

Robert Lanza

Accepted

The word expenditure has been changed to cost.

8548

2

4

2729

2762

Although a tier 2 method is described in the decision tree, there is no description of thetier 2 method in the guideline text. The description on the tier 2 method should be addedin the guideline text as well.

Takuji Terakawa

Accepted

The decision tree has been finalised. The decision tree refers to the methods
discussed in the text.

706

2

4

2732

2745

It is proposed that the authors elaborate on the Equations 4.3.2 and 4.3.3 to include all
greenhouse gases subject to reporting.

Mikhail Gitarskiy

Rejected

Looking at Volume 2, Stationary Combustion, the form of the equation that has
been used is consistent with equation 2.1.

6146

2

4

2739

2739

I suggest that the authors add a brief explanation on Tier 2.

Naofumi Kosaka

Accepted

The section on choice of methods has been rewritten to include explanations ofTier 1, 2 and 3 methods.

1406

2

4

2742

2742

Edit "…based on coke production processing stage and…"

Robert Lanza

Accepted

The text has been revised.

1408

2

4

2754

2754

Edit "… detailed fugitive emissions predictive model."Robert Lanza

Accepted

The text has been simplified.

1410

2

4

2755

2755

"Any models should be verified." Suggest providing a reference to standards/guidelines
for model verification, or other discussion of expectations of how models should beverified

Robert Lanza

Accepted

A cross reference to other parts of the 2006 GLs or the 2019 Refinement has
been provided.

1412

2

4

2762

2762

Edit "… Section 4.1 of this Chapter."Robert Lanza

Accepted

Text added.

1414

2

4

2766

2766

Table 4.3.5 "Note: Factor for "hard coal coke production (coking plants)" -- The inclusionof this note suggests that there are other types of processes to which this emission factor
does not apply. Suggest clarifying why this note is included.

Robert Lanza

Accepted withmodification

Further clarification about the applicability of the emission factor has been
added in the notes to the table.

2010

2

4

2766

2767

The statement is too simple to implement. Can the authors give more operational
instructions on how to verify or evaluate that the emissions from coke production are
realistic in magnitude in comparison with emissions from other categories in the iron steel
sector, and the energy sector?

DAN YU TIAN

Accepted withmodification

Text elaborated, and moved to the section on QA/QC.

1416

2

4

2774

2774

Edit "… from energy balance data or from plant operationss."

Robert Lanza

Accepted

Text corrected.

3970

2

4

2775

Andrea TILCHE

Accepted

A reference to the table has been added in the text.

1418

2

4

2775

2776

Suggest [throughout the guidelines, not only for this section] replacing "order ofmagnitude" with an actual range of numerical values, percentages, or other factors thatshould be applied by inventory compilers to the uncertainty assessment."

Robert Lanza

Accepted

1420

2

4

2776

2777

Section headings are missing from the "Flaring of Emissions" text. "Flaring of Emissions"text should include headings for "Methodological Issues" "Choice of Methods, Decision
Trees, Tiers" and other headings that are common to other sections.

Robert Lanza

Accepted

Table 4.3.6 seems not to be referred to in the text.

Authors note

These sections and associated text have been added.

Comment ID Volume

To lineComment

ExpertResponse

Authors note

6956

2

Chapter From line
4

2777

2777

This row stated: "Surplus coke oven gas may be flared if no other economic uses havebeen found for it." In Hungary, besides surplus coke oven gas, also surplus blast furnace
gas is flared in special cases (e.g. avoid to high pressure in the system). This flaring takes
place in a power plant which is built to use these gases as energy sources. Would it bepossible to add also a recommendation on where to allocate emissions from flaring of blast
furnace gas?

Klára Tarczay

Accepted

The text has been modified to include a reference to flaring for operationalsafety reasons. Box 4.1 has been added for a summary of flaring activities inmetallurgical coke and iron and steel production.

1422

2

4

2777

2777

"Surplus coke oven gas may be flared if no other economic uses have been found for it."In the Iron and Steel and Metallurgical Coke section (Chapter 4, Volume 3, Table 4.1a, it
is implied that COG would be flared in the event of "emergencies or COG consumer
maintenance" and not only because there is no economic use for the COG. the discussionsof COG flaring should be made consistent. Also, if COG is being flared because there isno economic use for it, such flaring would not be "unintentional" but would actually be an
inherent and routine part of the coke production process.

Robert Lanza

Accepted withmodification

The text has been modified to include a reference to flaring for operationalsafety reasons. The IPCC definition of fugitive emissions includes bothintentional or unintentional release of greenhouse gases.

6148

2

4

2780

2780

I suggest that the authors reconsider the correspondence between activity data andemission factor for flaring of surplus coke oven gas. If the default emission factors
provided in line 2795 through 2797 are applied to estimate the emissions, thecorresponding activity data should be the amount of surplus coke oven gas. However, theamount of coke production is selected as activity data in the proposed tier 1 method(Equation 4.3.4). If the authors wish to use the amount of coke production, an emission
factor should be developed.

Naofumi Kosaka

Accepted

The equation has been corrected and the EF and AD are now presented incompatible units.

2012

2

4

2780

2780

Based on the followed section “choice of emission factor” and “choice of activity data”,
the reviewer believes that the texts “based on coke production activity” should be
modified as “based on the amount of COG flared”.

DAN YU TIAN

Accepted

The equation has been corrected and the EF and AD are now presented incompatible terms.

2014

2

4

2785

2785

Error in equation 4.3.4. Emissions GHG = Activity coke production● Emission Factor
GHG should be Emissions GHG = Activity COG flared● Emission Factor GHG

DAN YU TIAN

Accepted

The equation has been corrected and the EF and AD are now presented incompatible terms.

2016

2

4

2787

2787

The texts “emissions of a given GHG by coke production (kg GHG)” should be modified
as “emissions of a given GHG from flaring of coke oven gas (kg GHG)”.

DAN YU TIAN

Accepted

The equation has been corrected and the EF and AD are now presented incompatible terms.

1424

2

4

2787

2796

The emission factor referred to in line 2789 is in units of kg GHG per tonne of cokeproduced; the emission factor referred to in line 2796 is in units of kg GHG per TJ of cokeoven gas. These emission factors are not consistent. For flaring the amount of COG
flared (in units of TJ) must first be known, and then the GHG emission factors for COG
flaring (combustion) must be applied. The amount of coke produced is not relevant to the
GHG emissions calculation for flaring unless it is being assumed that 100 percent of the
COG produced by the process is being flared.

Robert Lanza

Accepted

The equation has been corrected and the EF and AD are now presented incompatible terms.

1426

2

4

2787

2796

Suggest including two calculations and associated equations for COG flaring: 1. assume
that 100 percent of the COG produced by the process is being flared; 2. assume that somesubset of the total COG produced by the process is being flared. Calculation assumption
1. can be based on the amount of coke produced, the amount (tonnes) of COG produced
per tonne of coke produced (TJ COG produced per tonne coke produced), and theemission factors or COG combustion (kg GHG/TG COG). Calculation assumption 2.
would depend upon knowledge of how much (in units of TJ) of the total COG producedby the process is being flared.

Robert Lanza

Rejected

The equation has been corrected and the EF and AD are now presented incompatible terms. Inventory compilers can make their own choice about theassumptions about the quantities of COG flared.

2018

2

4

2788

2788

“Activity coke production = amount of coke produced (tonnes) “ should be “Activity
COG flared = amount of COG flared (TJ)”DAN YU TIAN

Accepted

The equation has been corrected and the EF and AD are now presented incompatible terms.

Comment ID Volume

ExpertResponse

2020

2

Chapter From line
42789

To line2790“emission factor according to COG released for each GHG (kg GHG/tonne of cokeproduction)” should be “emission factor according to COG flared for each GHG (kg
GHG/ TJ of COG flared)”Comment

DAN YU TIAN

Accepted

1428

2

4

2796

2796

Edit "… the Tier 1 emission factors for flaring (combustion) of coke oven gas …"

Robert Lanza

Accepted

4584

2

4

2796

2797

Do you expect the CH4 EF for combustion in boilers to be representative for flaring?

Ole-Kenneth Nielsen

Accepted withmodification

1430

2

4

2800

2800

See comments for Lines 2787 - 2796; Tier 1 activity data could be the amount of cokeproduced and the amount of COG produced per tonne of coke produced IF it is assumed
that all of the COG produced is being flared. Otherwise the Tier 1 activity data would
need to be the amount of COG flared (in units of TJ). If there was "no economic use" forthe COG, it could be assumed that 100 percent of the COG would be flared.

Robert Lanza

Accepted

The equation has been corrected and the EF and AD are now presented incompatible terms.

3972

2

4

2814

Is there a need for further guidance? Not clear

Andrea TILCHE

Accepted

The text has been elaborated and the placeholder in parenthesis reminding theauthors to elaborate the text has been removed.

708

2

4

2823

2991

It is proposed to move Section 4.3.2.4 (lines 2823 to 2991) to Appendix 4a.3 as the basis
for future methodological development. The current text in Appendix 4a.3 could bemerged with the text in Section 4.3.2.4.

Mikhail Gitarskiy

Rejected

As there was enough data to develop this section, the authors and CLAs agreed
that this text should not be placed in an Appendix.

7446

2

4

2824

2826

coal to gas used to be a common way in cokeries to generate town gas - please provide areference where to report these emisisons (e.g. chapter 3.11 - "Hydrogen Production" or
1.A.2)

Jens Reichel

Rejected

Although it is possible to use the outputs of CtL to Hydrogen Production, theprocess analysed in the 2019 Refinement 2006 Guidelines was restricted to the
Syngas production.

2022

2

4

2848

2848

DAN YU TIAN

Accepted

The text has been revised.

2024

2

4

2851

2851

The reviewer would suggest the authors to add a time frame to define the “conservative
estimate of 120 million tons of CO2 equivalent”. Per year maybe？

DAN YU TIAN

Accepted

The sentence now reads "...conservative annual estimate of 120 million tons of
CO2 equivalent".

3974

2

4

2869

Table 4.3.7 seems not to be referred to in the text.

Andrea TILCHE

Accepted

The table is now referenced.

3976

2

4

2899

Figure 4.3.8 should be Figure 4.3.5 - it seems.

Andrea TILCHE

Accepted

The figure number has been adjusted.

2026

2

4

2901

2904

“Fuel transformation processes” appears 4 times in Figure 4.3.5. The reviewer would
suggest the authors to change them all into “gasification transformation processes”

DAN YU TIAN

Accepted

The figure has been revised.

6150

2

4

2905

2967

I suggest that the authors reconsider the correspondence among activity data and emission
factor for the fugitive emissions from coal to liquids. Line 2967 states that "The activity
data required for a Tiers 1 and 2 are the amounts of syngas produced." However, line
2916 and 2928 require "total amount of feedstock of type i" as activity data. The
description shown above is inconsistent.

Naofumi Kosaka

Accepted

It was corrected. The activity data of CtL is the amount of syngas produced.

2656

2

4

2911

2921

Please list the unit of the variables.

Xiangzheng Deng

Accepted withmodification

Equation 4.3.5 was deleted.

2476

2

4

2911

2921

please check the units of variables in the formula

Mingshan Su

Accepted withmodification

Equation 4.3.5 was deleted.

290

2

4

2915

2919

Could you, please, unify the capital letters below the equation 4.3.5.

Sergii Shmarin

Accepted

Equation 4.3.5 was deleted.

2028

2

4

2917

2917

The dimensional unit for CFi was wrong. It should be “kg C/TJ” instead of “fraction”.

DAN YU TIAN

Accepted

Equation 4.3.5 was deleted.

Word error. “CtL plan CO2” should be “CtL plant CO2”

Authors note
The equation has been corrected and the EF and AD are now presented incompatible terms.

The guidance on the choice of emisson factor has been modified.

Comment ID Volume

ExpertResponse2030

2

Chapter From line
42919

To line2919

The explanation of “EF” was wrong. It should be the conversion factor or the ratio ofcarbon emitted as CO2 (including carbon monoxide emitted to the atmosphere as themolar equivalent amount of CO2) to the total carbon contained in the feedstocks,
expressed as a fraction, instead of “aggregate CO2 emission factor, kg CO2/TJ”

DAN YU TIAN

Accepted

Equation 4.3.5 was deleted.

2032

2

4

2944

2944

“The ultimately affects …” should be “They ultimately affects …”

DAN YU TIAN

Accepted

The paragraph has been reworded.

3978

2

4

2952

Table 4.3.14 does not seem to exist in the text.

Andrea TILCHE

Accepted

Table number corrected to 4.3.10.

3980

2

4

2956

Table 4.3.8 is not referred to in the text - it seems.

Andrea TILCHE

Accepted

The table is now referred to in the text.

2034

2

4

2956

The dimensional units of the emission factors for gasification processes of CtL as shownin Table 4.3.8, may not be consistent with Equation 4.3.5 and 4.3.6, which use the amountof feedstocks, instead of output, as activity data.

DAN YU TIAN

Accepted

Equation 4.3.5 was deleted and the equation 4.3.6 units were corrected to beconsistent with table 4.3.8.

3982

2

4

2964

Table 4.3.9 is not referred to in the text - it seems.

Andrea TILCHE

Accepted

The table is now referred to in the text.

3984

2

4

2967

The word "activity" is not spelt correctly

Andrea TILCHE

AcceptedSpelling mistake corrected.

2036

2

4

2967

2967

This sentence states that “the actvity data required for a Tiers 1 and 2 are the amounts ofsyngas produced in terajoules (TJ)”. Nevertheless, Equation 4.3.5 and 4.3.6 use theamount of feedstocks, instead of output, as activity data. The reviewer would suggest theauthors to check and make appropriate modification to keep consistency of themethodological guidance. By the way “The actvity data” should be “The activity data”

DAN YU TIAN

Accepted

Equation 4.3.5 was deleted and the equation 4.3.6 units were corrected to beconsistent with table 4.3.8.

1866

2

4

3027

3028

More specific QA/QC procedures for fugitive emissions can be provided here. In
particular, energy accounts under the System of Environmental-Economic Accounting(SEEA) provide information on energy losses during extraction, distribution, storage andtransformation of energy products. These losses cover resident economic units and arereported by industry, according to the International Standard Industry Classification. The
economic statistics sections of many countries' National Statistical Offices (NSOs)
produce these accounts, including EU countries (where it is mandated). Making mentionof specific independently compiled data sets such as SEEA energy accounts can facilitate
the QA/QC procedure for fugitive emissions. Existing bridging tables between SEEA airemission accounts and IPCC reporting can furthermore faciilitate the effectiveness ofusing SEEA air emission accounts in the QA/QC process.
Bridging tables for air emissions accounts can be found on pg. 51 and 85 of the Eurostat
air emissions handbook (http://ec.europa.eu/eurostat/documents/3859598/7077248/KSGQ-15-009-EN-N.pdf/ce75a7d2-4f3a-4f04-a4b1-747a6614eeb3) and on pg. 14 of the EU
regulation on envrionmental economic accounts (https://eur-lex.europa.eu/legalcontent/EN/TXT/PDF/?uri=CELEX:02011R0691-20140616&from=EN).

Jessica Chan

Accepted

The text has been updated and revised.

2957

Comment

Authors noteComment ID Volume

To lineComment

ExpertResponse

2130

2

Chapter From line
4

3027

3028

More specific QA/QC procedures for fugitive emissions can be provided here. In
particular, energy accounts under the System of Environmental-Economic Accounting(SEEA) provide information on energy losses during extraction, distribution, storage andtransformation of energy products. These losses cover resident economic units and arereported by industry, according to the International Standard Industry Classification. The
economic statistics sections of many countries' National Statistical Offices (NSOs)
produce these accounts, including EU countries (where it is mandated). Making mentionof specific independently compiled data sets such as SEEA energy accounts can facilitate
the QA/QC procedure for fugitive emissions. Existing bridging tables between SEEA airemission accounts and IPCC reporting can furthermore faciilitate the effectiveness ofusing SEEA air emission accounts in the QA/QC process.
Bridging tables for air emissions accounts can be found on pg. 51 and 85 of the Eurostat
air emissions handbook (http://ec.europa.eu/eurostat/documents/3859598/7077248/KSGQ-15-009-EN-N.pdf/ce75a7d2-4f3a-4f04-a4b1-747a6614eeb3) and on pg. 14 of the EU
regulation on envrionmental economic accounts (https://eur-lex.europa.eu/legalcontent/EN/TXT/PDF/?uri=CELEX:02011R0691-20140616&from=EN).

Julian Chow

Accepted

The text has been updated and revised.

2912

2

4

3716

3717

The text of the flow diagram is not distinguishedPoot-Delgado Carlos
Antonio

Accepted

Heading for Figure 4a.2.3 edited to read “Proposed decision Tree for estimating
Fugitive Emissions from Wood Pellet Production”. This makes the text
distinguished.

2038

2

4

3808

3808

The dimensional unit for CFi was wrong. It should be “kg C/TJ” instead of “fraction”.

DAN YU TIAN

Accepted

The equation was reviewed and modified to [EGAS i = (FSj • EFi) • 10-6]. In
other words, to calculate GHG emissions (CO2, CH4 and N2O) from BtL and
BtG, is necessary multiply the total amount of biomass or syngas produced (TJ)
to the Emission Factor of biomass or syngas.

2040

2

4

3809

3809

The explanation of “EFi” was wrong. It should be the conversion factor or the ratio ofcarbon emitted as CO2 (including carbon monoxide emitted to the atmosphere as themolar equivalent amount of CO2) to the total carbon contained in the feedstocks,
expressed as a fraction, instead of “aggregate gas i emission factor, kg gas i/Gg or TJ offeedstock j”

DAN YU TIAN

Accepted

The equation was reviewed and modified to [EGAS i = (FSj • EFi) • 10-6]. In
other words, to calculate GHG emissions (CO2, CH4 and N2O) from BtL and
BtG, is necessary multiply the total amount of biomass or syngas produced (TJ)
to the Emission Factor of biomass or syngas.

2042

2

4

3845

3845

The explanation of “EFi” was wrong. It should be the conversion factor or the ratio ofcarbon emitted as CO2 (including carbon monoxide emitted to the atmosphere as themolar equivalent amount of CO2) to the total carbon contained in the feedstocks,
expressed as a fraction, instead of “aggregate gas i emission factor, kg gas i/Gg offeedstock j”

DAN YU TIAN

Accepted

The equation was reviewed and modified to [EGAS i = (FSj • EFi) • 10-6]. In
other words, to calculate GHG emissions (CO2, CH4 and N2O) from BtL and
BtG, is necessary multiply the total amount of biomass or syngas produced (TJ)
to the Emission Factor of biomass or syngas.

354

2

4

Tinus Pulles

Accepted

MINGMING WANG

Rejected

where to report CO2 emissions? E.g from flaring of coke oven gas ( Vol 2 chap 4 line
4792 f )Jens Reichel

Accepted

worksheets require CO2, CH4 and N2O - in the volume 2 chap 4 NMVOC emission
factors are provided - where to report NMVOC?

Jens Reichel

Rejected

My comments on the FOD were mainly aimed at the sometimes in my view too many
signifianct digits provided for many default emission factros. I noted that these comments
have not been resulted in changing these values. So I ask you to lookk at this again.

Authors noteI have no forther comments.
8858

2

4

7452

2

Annexes7450

2

Annexes

Default emission factors for fugitive emissions are generally too coarse. More refined data
at more granular geographic level would be more helpful.
17

18

In general, limited data are available for fugitive emission sources, andproviding more granular factors would not necessarily improve accuracy of theestimates.

Per 2006 GL, we are not including NMVOC in the worksheets.

Comment ID Volume

Chapter From line

ExpertResponse

co2 and ch4: letter case.

Håkon F. Skullerud

Accepted

No refinment was made to Tables 2.2, 2.3 and 2.4. However, default emission factors forstationary industrial combustion are considered too general, and it is recommended that
IPCC expands the disaggregation by types of equipment (boilers, furnaces, etc.),
technology and capacity, to reflect difference in emissions from different types ofequipment.

MINGMING WANG

Rejected

No action can be taken because comment is out of scope of 2019 Refinement.

Section 12.5, Chapter 12, Volume 4 (AFOLU) of the 2019 Refinement does not provide
the guidance on how CO2 emissions from buring woody biomass feedstocks should betreated in the Energy sector. Therefore, it is proposed to include the following text in line
56: "The CO2 and non-CO2 emissions from burning wood biomass for energy purposes
may be reported in the same country or in different countries. It is good practice toidentify the approach applied for reporting on CO2 emissions in the country, where theenergy feedstocks from harvested wood were produced. The country should decide on
inclusion of CO2 emissions from wood biomass burning in national inventory totals in the
Energy sector depending on the approach for reporting CO2 emissions and removals
applied by the country-producer of the HWP." The existing text in lines 56 and 57 remains
unchanged and wouldfollow the inclusion proposed.

Mikhail Gitarskiy

Accepted withmodification

Accepted with modification. Additional detail on treatment of biomass has
been provided in 2.3.3.4, and the text directs users to Section 12.5, Chapter 12of the AFOLU volume for additional information on HWP

I agree with the idea of treating biomass as a special case. However, we must make theproviso that emissions from the combustion of biofuels have only an informative purpose,
which are not included in the totals to avoid double counting, leaving me the concern ofwhether that decision is lost or not it is recognized as a proportion of the total. And myfinal question, does it exist or can we establish some measurement methodology thatallows us to disaggregate the data by source of GHG emissions? If the interest of the datais to use it as a focal point to establish public policies aimed at reducing GHGs, then it isconvenient to disaggregate it.

Alma Vargas

Accepted withmodification

Additional detail on biomass has been provided in the FD. Emissions frombiomass combustion are estimated with methods available in the 2006 IPCC
guidelines, volume 2, chapter 2: Stationary Combustion.

3

The FOD does not contain any update to section 3.6 Civil aviation. Sub-national
governments often do not have access to airport and flight data, whereas national
government or agencies mostly do. Therefore, it is strongly recommended that IPCC
requires national inventories to report aviation emissions per airport and even per flight
where possible.

MINGMING WANG

Rejected

No action can be taken because comment is out of scope of 2019 Refinement.

2

3

To improve modelling of LTO emissions, it is strongly recommended that IPCC expands
the EEA methods to provide average taxi-time data for airports outside EU and USA, andto update the current ICAO default values of taxi-time becuse they are quite rough andlikely too high for small and medium sized airports and too low for poorly managed large
airports.

MINGMING WANG

Rejected

No action can be taken because comment is out of scope of 2019 Refinement.

2

3Section 3.3.1.4 (Completeness) states that carbon from biomass should be estimatedseparately and reported as an information item to avoid double accounting, as theseemissions are already treated in the AFOLU sector. Will the IPCC provide further
guidance on emissions from combustion of renewable diesel (RD)? How can nations (andcities) share the accountability of emissions generated by the RD combustion, if RD is
produced in a different country?

MINGMING WANG

Rejected

No action can be taken because comment is out of scope of 2019 Refinement.

3412

2

4

87

8850

2

2

19

656

2

2

56

7992

2

2

2.3.3.4

8852

2

8854

8856

To line87

57

Comment

Authors note