CLIMATE LEADERS GREENHOUSE GAS INVENTORY PROTOCOL

           CORE MODULE GUIDANCE
           Direct Emissions from
           Mobile Combustion Sources
CLIMATED
U.S. Environmental Protection Agency
October 2OO4

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The Climate Leaders Greenhouse Gas Inventory Protocol is based on the Greenhouse Gas Protocol (GHG Protocol)
developed by the World Resources Institute (WRI) and the World Business Council for Sustainable Development
(WBCSD). The GHG Protocol consists of a corporate accounting and reporting standard and separate calculation
tools. The Climate Leaders Greenhouse Gas Inventory Protocol is an effort by EPA to enhance the GHG Protocol to fit
more precisely what is needed for Climate Leaders. The Climate Leaders Greenhouse Gas Protocol consists of the fol-
lowing components:

•  Design Principles Guidance

•  Core Modules Guidance

•  Optional Modules Guidance

All changes and additions to the GHG Protocol made by Climate Leaders are summarized in the Climate Leaders
Greenhouse Gas Inventory Protocol Design Principles Guidance.

For more information regarding the Climate Leaders Program, visit us on the web at www.epa.gov/climateleaders

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  Mobile Combustion  Sources —  Guidance

1. Introduction	1
  1.1. Core Direct versus Optional Indirect Emissions	1
  1.2. Greenhouse Gases Included	2
  1.3. Bio Fuels	3
2. Methods for Estimating CO2 Emissions	4
3. Method for Estimating CH4 and N2O Emissions	7
4. Choice of Activity Data and Emission
   Calculation Factors	1O
  4.1. Activity Data	10
  4.2. Emission Calculation Factors	13
5. Completeness	15
6. Uncertainty Assessment	16
7. Reporting and Documentation	17
8. Inventory Quality Assurance and Quality
   Control (QA/QC)	18
Appendix A: Calculating CH4 and N2O Emissions
from Mobile Combustion Sources	19
Appendix B: Calculating CO2 Emissions from Mobile
Combustion Sources	26
  Motor Gasoline and Diesel Fuel	26
  Fuel Oil, Aviation Gasoline, and Jet Fuel	27
  Liquefied Petroleum Gases (LPG)	28
  Natural Gas (Compressed and Liquefied)	29
  Ethanol	30
  Biodiesel	31
                       CLIMATE LEADERS GHG  INVENTORY  PROTOCOL

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                            Mobile Combustion Sources  — Guidance
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CLIMATE  LEADERS GHG  INVENTORY  PROTOCOL

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  Mobile Combustion  Sources  —  Guidance

Introduction
       Greenhouse gas (GHG) emissions are
       produced by mobile sources as fossil
       fuels are burned. Carbon dioxide
(C02), methane (CH4) and nitrous oxide (N20)
are emitted directly through the combustion of
fossil fuels in different types of mobile equip-
ment. A list of mobile sources that could
potentially be included in a Climate Leaders
Partners' GHG inventory is given in Table 1.
GHG emissions from mobile sources also
include hydrofluorocarbon (HFC) and perfluo-
rocarbon (PFC) emissions from mobile air
conditioning and transport refrigeration leaks.
The calculation of HFC and PFC emissions from
mobile sources is described in the Climate
Leaders guidance tor Direct HFC and PFC
Emissions from Use of Refrigeration & Air
Conditioning Equipment.

1.1.  Core  Direct
versus Optional
Indirect  Emissions
This document presents the guidance for esti-
mating Core Direct GHG emissions resulting
from the operation of owned or leased mobile
               Table 1: Categories of Mobile Sources

Category                                            Primary Fuels Used
Highway Vehicles
—Passenger Cars
—Vans, Pickup Trucks & SUVs
—Light trucks
—Combination Trucks
—Buses

Non-Road Vehicles
—Construction Equipment
—Agricultural Equipment
—Other Off-Road Equipment

Waterborne
—Freighters
—Tankers

Rail
—Amtrak
—Commuter Rail
—Freight Trains

Air
—Commercial Aircraft
—Executive Jets
          Gasoline
          Diesel Fuel
          Diesel Fuel
          Gasoline
          Diesel Fuel
          Residual Fuel Oil
          Diesel Fuel
          Electric
          Kerosene Jet Fuel
                          CLIMATE  LEADERS  GHG  INVENTORY PROTOCOL

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                                 Mobile  Combustion  Sources  —  Guidance
        sources. This guidance applies to all sectors
        whose operations include owned or leased
        mobile sources.

        All other company-related mobile source emis-
        sions, including employee commuting,
        employee travel, and upstream/downstream
        third party transportation emissions, such as
        those associated with transporting material
        inputs or product distribution, are considered
        Optional Indirect emissions. This guidance
        document focuses only on the Core Direct
        emissions estimates. There are separate
        guidance documents being developed that
        focus on the Optional Indirect sources related
        to mobile source emissions.

        1.2.  Greenhouse
        Gases  Included
        The greenhouse gases C02, CH4,  and N20 are all
        emitted  during the combustion of fossil fuels in
        mobile sources. For  many transportation
        modes, N20 and CH4 emissions comprise a
        relatively small proportion of overall
        transportation related GHG emissions (-1-2 %
        combined). However, for gasoline fueled high-
        way vehicles (e.g., passenger cars and light
        trucks) N20 and CH4 could be a more significant
        (-5/6) portion of total GHG emissions1. N20  and
        CH4 emissions are likely to be an even higher
        percentage of total GHG emissions from alter-
        nate fueled vehicles.

        The approach to estimating C02  emissions
        from mobile combustion sources varies signifi-
cantly from the approach to estimating CH4 and
N20 emissions. While C02 can be reasonably
estimated by applying an appropriate carbon
content and fraction of carbon oxidized factor
to the fuel quantity consumed, CH4 and N20
emissions depend largely on the emissions
control equipment used (e.g.,  type of catalytic
converter) and vehicle miles traveled.
Emissions of these gases also  vary with the
efficiency and vintage of the combustion tech-
nology, as well as maintenance and operational
practices. Due to this complexity, a much high-
er level of uncertainty exists in the estimation
of CH4 and N20 emissions from mobile combus-
tion sources, compared to the estimation of
C02 emissions.

Climate Leaders Partners are required to
account for emissions of all three GHGs from
mobile combustion sources2. Information on
methods used to calculate C02 emissions is
found in Section 2. Information on an approach
for determining CH4 and N20 emissions is
found in Section 3. However, due to the relative
emission contribution of each gas, this docu-
ment primarily deals with guidance for
estimating C02 emissions from mobile combus-
tion sources.

Climate Leaders Partners account for emis-
sions resulting directly from their activities,
and do not account for the full life cycle green-
house gas emissions associated with those
activities. For example, a fleet owner is respon-
sible for accounting for emissions resulting
from the burning of fuel from the fleet, but not
        1  Relative contribution of each gas was determined based on total emissions of each gas by transportation mode in terms of
          COj-equivalent emissions. Data were taken from U.S. EPA 2004 Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2002,
          EPA430-R-04-003.
        2  Partners are also required to account for HFC and PFC emissions from mobile air conditioning and refrigerated transport as
          applicable, as outlined in the Climate Leaders guidance for Direct HFC and PFC Emissions from Use of Refrigeration &Air
          Conditioning Equipment.
CLIMATE  LEADERS  GHG  INVENTORY  PROTOCOL

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  Mobile  Combustion  Sources  —  Guidance

for the emissions associated with producing
the fuel. For the purposes of the Climate
Leaders Program, fuel-processing emissions are
considered the direct responsibility of the fuel
producer.

Partners should be aware, however, that the
choice of transportation modes and fuels can
greatly influence GHG emissions from a life
cycle perspective. A transportation mode may
have relatively few GHG emissions from the
vehicle itself, but emissions could be higher
from the production of the fuel. Therefore,
Partners are encouraged to consider the full
life cycle impacts of fuels when analyzing dif-
ferent transportation modes and fuel options.

1.3.  Bio  Fuels

Non-fossil fuels (e.g., ethanol, bio-diesel) may
be combusted in mobile sources. The C02
emissions from combustion of these fuels are
reported as biomass C02 emissions and are
tracked separately from fossil C02 emissions.
Partners are required to report biomass C02
emissions from mobile sources using non-fossil
fuels in terms of total amount of biomass C02
emitted.

There are several transportation fuels that  are
actually blends of fossil and non-fossil fuels.
For example E85 is made up of 85% ethanol
(non-fossil fuel) and 15% gasoline (fossil fuel)
and B20 is a blend of 20% bio-diesel (non-fossil
fuel) and 80% diesel fuel (fossil fuel).
Combustion of these blended fuels result in
emissions of both fossil C02 and biomass C02.
Partners should report both types of C02 emis-
sions if these blended fuels are used.
                             CLIMATE LEADERS  GHG INVENTORY PROTOCOL

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                               Mobile  Combustion  Sources  —  Guidance
        Methods   for  Estimating   CO2
        Emissions
              The C02 emissions associated with fuel
              combustion are a function of the vol-
              ume of fuel combusted, the density of
       the fuel, the carbon content of the fuel, and the
       fraction of carbon that is oxidized to C02.
       When the fuel density and carbon content by
       mass are known, C02 emissions can be deter-
       mined directly. Often, however, this
       information may not be readily available for a
       particular  fuel. The C02 emissions can then be
       estimated  from the heat content of the fuel and
       the carbon content per unit of energy. Carbon
       content factors per energy unit are often used
       because they are less variable than published
       carbon content factors per physical unit.
       Either of these methods is an acceptable
       approach for Climate Leaders Partners to use.3
                                C02 emissions are calculated directly with the
                                carbon content of the fuel, the fuel density, and
                                the fraction of carbon oxidized for each fuel
                                type. Equation 1 presents an overview of this
                                approach.

                                The complete steps involved with estimating
                                C02 emissions with this approach are shown
                                below.

                                Step 1: Determine the amount of fuel com-
                                   busted. This can be determined from a
                                   "top-down" approach based on fuel
                                   receipts, purchase records, or through
                                   direct measurement at the mobile source.
                                   Fuel use can also be based on a "bottom-
                                   up" approach based on using vehicle
                                   activity data and fuel  economy factors to
                                   generate an estimate of fuel consumed.
             Equation  1: Density and Carbon Content Approach for
                                 Estimating  CO2 Emissions
                   n                        CO
        Emissions =V  Fuel, x FD, x C, x FO, x    Jfl-"°
        where:
                  1=1
FDi

Q


CO

C
                  = Volume of Fuel Type i Combusted
                                        f mass  ~\
                  = Density of Fuel Type i  I —:	1
           2 (m.w.)
                                       (mass C "\
                                      m^cc fii  ,  I
                                      mass ruei  t
= Fraction Oxidized of Fuel Type i

= Molecular weight of C02

= Molecular Weight of Carbon
       3 EPA uses both approaches for different purposes. For the purposes of calculating fuel economy, and in the MOBILE 6.3 model, EIA
         uses the fuel density and carbon content fraction as outlined in 40 CFR 600.113. In the U.S. EPA 2004 Inventory of U.S. Greenhouse
         Gas Emissions and Sinks: 1990-2002, EPA430-R-04-003, EPA uses the energy based carbon factor approach due to data availability
         and to be consistent with Intergovernmental Panel on Climate Change (IPCC) guidelines.
CLIMATE  LEADERS  GHG  INVENTORY PROTOCOL

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  Mobile  Combustion  Sources  —  Guidance
   Methods for determining fuel use are dis-
   cussed in Section 4.1.

Step 2: Determine fuel density and carbon con-
   tent of the fuels consumed. Fuel carbon
   content and density values are determined
   based on fuel analysis data (discussed in
   Section 4.2). The fuel density (mass/volume)
   can then be multiplied by the carbon con-
   tent, or weight fraction of carbon in the fuel,
   (mass C/mass fuel) to determine mass of C
   per volume of fuel. Default values in terms of
   mass of C per volume are given for gasoline
   and on-road diesel fuel in Table 5 of Section
   4.2.

Step 3: Estimate carbon emitted. When fuel is
   burned, most of the carbon is eventually
   oxidized to C02 and emitted to the atmos-
   phere. To account for the small fraction that
   is not oxidized and remains trapped in the
   ash, multiply the carbon content by the
   fraction of carbon oxidized. Partners should
   use oxidation factors specific to the com-
   bustion source if known. Otherwise,
                                              Appendix B lists oxidation factors by fuel
                                              type. Default values are given for gasoline
                                              and on-road diesel fuel in Table 5 of Section
                                              4.2.

                                           Step 4: Convert to CO2 emitted. To obtain total
                                              C02 emitted, multiply carbon emissions by
                                              the molecular weight ratio of C02 (m.w. 44)
                                              to carbon (m.w. 12) (44/12).

                                           When calculating C02 emissions from the car-
                                           bon content per unit of energy approach,
                                           emissions are calculated by applying a carbon
                                           content and fraction of carbon oxidized factor
                                           to the total fuel consumption for each fuel
                                           type.  Equation 2 presents an overview of this
                                           approach.

                                           The steps involved with estimating C02 emis-
                                           sions with this approach are shown below.

                                           Step 1: Determine the amount of fuel com-
                                              busted. This can be determined from a
                                              "top-down" approach based on fuel
                                              receipts, purchase records, or through
   Equation 2: Carbon Content per Unit of Energy Approach
                       for Estimating CO2  Emissions
Emissions =

where:
               Fuel x HC, x C, x FO, x
                                     CO
                                       2 (m.w.)
                                      C
                                       (m.w.)
 HC,

 C,

 F0i

 CO,
          =  Volume of Fuel Type i Combusted
                                           (energy   -\
                                        volume of fuel J
          =  Carbon Content Coefficient of Fuel Type i ^ mass C
 *" (m.w.)
          =  Fraction Oxidized of Fuel Type i

          =  Molecular weight of C02

          =  Molecular Weight of Carbon
                                                     energy
)
                            CLIMATE  LEADERS  GHG  INVENTORY  PROTOCOL

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                                Mobile  Combustion  Sources  —  Guidance
           direct measurement at the mobile source.
           Fuel use can also be based on a "bottom-
           up" approach based on using vehicle
           activity data and fuel economy factors to
           generate an estimate of fuel consumed.
           Methods for determining fuel use are dis-
           cussed in Section 4.1.

        Step 2: Convert the amount of fuel combusted
           into energy units. The amount of fuel com-
           busted is typically measured in terms of
           physical units (e.g., gallons or barrels). This
           needs to be converted to amount of fuel
           used  in terms of energy units. If the heating
           value of the specific fuel purchased is not
           known then default fuel specific heating val-
           ues listed in Appendix B can be applied. To
           convert the amount of fuel combusted into
           an  amount of energy used, multiply the vol-
           ume of fuel used (total number of gallons or
           barrels of fuel) by the heating value of the
           fuel, expressed in units of energy per units
           of volume.

        Step 3: Estimate carbon content of fuels con-
           sumed. To estimate the carbon content,
   multiply energy content for each fuel by
   fuel-specific carbon content coefficients
   (mass C/energy). The fuel supplier may be
   able to provide these carbon content coeffi-
   cients. Otherwise, U.S. average coefficients
   for each fuel type provided in Appendix B
   should be used.

Step 4: Estimate carbon emitted. When fuel is
   burned, most of the carbon is eventually
   oxidized to C02 and emitted to the atmos-
   phere. To account for the small fraction that
   is not oxidized and remains trapped in the
   ash, multiply the carbon content by the
   fraction of carbon oxidized. Partners should
   use oxidation factors specific to the com-
   bustion source if known. Otherwise,
   Appendix B lists oxidation factors by fuel
   type. Default values are given for gasoline
   and on-road diesel fuel in Table 5 of Section
   4.2.

Step 5: Convert to CO2 emitted. To obtain total
   C02 emitted, multiply carbon emissions by
   the molecular weight ratio of C02 (m.w. 44)
   to carbon (m.w. 12) (44/12).
CLIMATE  LEADERS GHG  INVENTORY  PROTOCOL

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  Mobile  Combustion  Sources  —  Guidance
Method  for   Estimating  CH4  and
N2O   Emissions

       The basic calculation procedure for esti-
       mating CH4 and N20 emissions from
       mobile combustion sources is repre-
sented by Equation 3.

     Equation  3: Estimation
    Method for  CH4  and  N2O
              Emissions
Emissionsps = As x EFps
where,

p    =  Pollutant (CH4 or N20)

s    =  Source Category

A    =  Activity Level

EF   =  Emission Factor

As mentioned, N20 and CH4 emissions depend
not only on the fuel characteristics but also on
the combustion technology type and control
technologies. N20 is influenced by catalytic
converter design, while CH4 is a byproduct of
combustion, but can also be affected by cat-
alytic converter design. N20 and CH4 emissions
are often estimated as a function of vehicle
miles traveled. Table 2 provides emission fac-
tors by types of highway vehicles and control
technologies. Information on the control tech-
nology type of each vehicle is posted on an
under-the-hood label. To estimate emissions,
Partners can multiply the appropriate emission
factor by the number of miles traveled for each
vehicle type.
Determining the specific control technologies
of vehicles in the fleet gives the most accurate
estimate of CH4 and N20 emissions. Partners
should be aware that in order to account for
reductions obtained from certain emission sav-
ings strategies it is necessary to use this
approach and determine the particular emis-
sion control technologies for the vehicles in
question.

If determining the specific technologies of the
vehicle in a fleet is not possible, or is too labor
intensive for a particular fleet, Partners can
estimate CH4 and N20 emissions using a weight-
ed average of available control technologies by
model year. (Partners would only need to know
the model year of their vehicles.) Weighted
emission factors are provided in Table 3.
(These factors were calculated from Table 2
and Tables A-2 through A-5 in Appendix A.)
This method is not recommended if Partners
plan to implement fleet related activities to
reduce CH4 and N20 emissions to meet their
Climate Leaders goal.

EPA strongly recommends that Partners keep
track of vehicle miles traveled, but if this data
is not available, Partners can estimate vehicle
miles by multiplying fuel used by the appropri-
ate vehicle fuel economy (expressed in miles
per gallon). More detail on obtaining fuel econ-
omy data is in Section 4.1.

Emission factors for other types of mobile
sources are given  in Tables A-6 and A-7 of
Appendix A.
                            CLIMATE LEADERS GHG  INVENTORY PROTOCOL

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                                     Mobile  Combustion  Sources  —  Guidance
          Table 2:  CH4 and N2O Emission  Factors for Highway Vehicles4
                                                       Emission Factor
                                                       (Grams per mile)
Emission Factor
(Grams per Km)
Vehicle Type/Control Technology
Gasoline Passenger Cars
Low Emission Vehicles
Tier 1
TierO
Oxidation Catalyst
Non-Catalyst
Uncontrolled
Gasoline Light-Duty Trucks
Low Emission Vehicles
Tier 1
TierO
Oxidation Catalyst
Non-Catalyst
Uncontrolled
Gasoline Heavy-Duty Vehicles
Low Emission Vehicles
Tier 1
TierO
Oxidation Catalyst
Non-Catalyst
Uncontrolled
Diesel Passenger Cars
Advanced
Moderate
Uncontrolled
Diesel Light Trucks
Advanced
Moderate
Uncontrolled
Diesel Heavy-Duty Vehicles
Advanced
Moderate
Uncontrolled
Motorcycles
Non-Catalyst Control
Uncontrolled
N2O
0.0283
0.0463
0.0816
0.0518
0.0166
0.0166
0.0355
0.058
0.1022
0.0649
0.0208
0.0208
0.1133
0.1394
0.2361
0.1499
0.048
0.048
0.0161
0.0161
0.0161
0.0322
0.0322
0.0322
0.0483
0.0483
0.0483
0.0073
0.0073
CH4
0.0402
0.0483
0.0644
0.1127
0.1931
0.2173
0.0483
0.0563
0.1127
0.1448
0.2253
0.2173
0.0708
0.0966
0.1207
0.1448
0.2012
0.4345
0.0161
0.0161
0.0161
0.0161
0.0161
0.0161
0.0644
0.0805
0.0966
0.2092
0.4184
N2O
0.0176
0.0288
0.0507
0.0322
0.0103
0.0103
0.022
0.0361
0.0635
0.0403
0.0129
0.0129
0.0704
0.0866
0.1467
0.0932
0.0298
0.0298
0.01
0.01
0.01
0.02
0.02
0.02
0.03
0.03
0.03
0.0045
0.0045
CH4
0.025
0.03
0.04
0.07
0.12
0.135
0.03
0.035
0.07
0.09
0.14
0.135
0.044
0.06
0.075
0.09
0.125
0.27
0.01
0.01
0.01
0.01
0.01
0.01
0.04
0.05
0.06
0.13
0.26
         Notes: The categories "Tier 0" and "Tier 1" were substituted for the early three-way catalyst and advanced three-way catalyst cate-
           gories, respectively, as defined in the Revised 1996 IPCC Guidelines. Methane emission factor for gasoline heavy duty trucks with
           oxidation catalyst assumed based on light-duty trucks oxidation catalyst value.
         4 From Annex 3.2 of U.S. EPA 2minventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2002, EPA430-R-04-003. Appendix A of
           this guidance document contains further information on these factors.

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  Mobile  Combustion  Sources  —   Guidance

                 Table  3: Weighted Average  Model Year
       CH4 and  N2O  Emission Factors for Highway Vehicles
                           Emission Factor
                           (Grams per Mile)
                            N20     CH4
 Emission Factor
(Grams per Mile)
  N20     CH4
Gasoline Fueled Vehicles
Passenger Cars
Model Years 1984-1993
Model Year 1994
Model Year 1995
Model Year 1996
Model Year 1997
Model Year 1998
Model Year 1999
Model Year 2000
Model Year 2001
Model Year 2002
Vans, Pickup Trucks, SUVs
Model Years 1987-1993
Model Year 1994
Model Year 1995
Model Year 1996
Model Year 1997
Model Year 1998
Model Year 1999
Model Year 2000
Model Year 2001
Model Year 2002
Heavy-Duty Vehicles
Model Years 1985-1986
Model Year 1987
Model Years 1988-1989
Model Years 1990-1995
Model Year 1996
Model Year 1997
Model Year 1998
Model Year 1999
Model Year 2000
Model Year 2001
Model Year 2002

0.0816
0.0675
0.0534
0.0463
0.0459
0.0440
0.0404
0.0362
0.0288
0.0285

0.1003
0.0845
0.0668
0.058
0.058
0.0535
0.0483
0.0501
0.0357
0.0378

0.0531
0.0915
0.1017
0.1256
0.1517
0.1453
0.1384
0.1337
0.1274
0.1300
0.1313

0.0644
0.0580
0.0515
0.0483
0.0481
0.0473
0.0456
0.0438
0.0404
0.0403

0.1143
0.0901
0.0676
0.0563
0.0563
0.0547
0.0529
0.0535
0.0484
0.0491

0.1984
0.1807
0.1750
0.1642
0.1111
0.1026
0.0956
0.0909
0.0847
0.0873
0.0886
Diesel Fueled Vehicles
Passenger Cars
Model Years 1966-2002 0.0161 0.0161

Light Trucks
Model Years 1966-2002 0.0322 0.0161

Heavy-Duty Vehicles
Model Years 1966-1 982 0.0483 0.0966
Model Years 1983-1 995 0.0483 0.0805
Model Years 1996-2002 0.0483 0.0644























Sources: U.S. EPA 2004, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2002, EPA430-R-04-003. All values are calculated
  from Tables A-l through A-5 presented in Appendix A of this guidance document, which have been directly taken from the
  inventory report. Gasoline passenger car, truck, and heavy-duty vehicles are weighted values, weighted by relative control
  technology assignments for vehicles sold in those model years. For emission factors from later model years, consult EPA.
                               CLIMATE  LEADERS GHG  INVENTORY  PROTOCOL

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                                   Mobile  Combustion  Sources  —  Guidance
             Choice  of  Activity  Data  and
             Emission  Calculation   Factors
             4.1.  Activity Data
             When calculating C02 emissions, the first piece
             of information that needs to be determined is
             the quantity of fuel combusted. The most accu-
             rate method of determining the amount of fuel
             combusted, and therefore the preferred
             method, is based on a top-down approach,
             which accounts for the total amount of fuel
             used in mobile sources. Total amount of fuel
             use can be determined through direct measure-
             ments of fuel use obtained from purchase
             records, storage tank measurements, or avail-
             able in other company records.

             If purchase records are used, changes in fuel
             storage inventory could lead to differences
             between the amount of fuel purchased and the
             amount of fuel actually combusted during a
             reporting period. For changes in fuel storage
             inventory, Equation 4 can be used to convert fuel
             purchase data to estimates of actual fuel use.

               Equation 4: Accounting  for
               Changes in  Fuel Inventory
             Fuel B = Fuel P + (Fuel ST - Fuel SJ

             where:

             Fuel B  =  Fuel burned in reporting period

             Fuel P  =  Fuel purchased in reporting period

             Fuel ST =  Fuel stock at start of reporting period

             Fuel SE =  Fuel stock at end of reporting period
                                               It is possible that Partners may only know the
                                               dollar amount spent on a type of fuel, however,
                                               this is the least accurate method of determining
                                               fuel use and is not recommended for Climate
                                               Leaders reporting. If the dollar amount spent on
                                               fuel is the only information available, it is recom-
                                               mended that Partners go back to their fuel
                                               supplier to get more information. If absolutely no
                                               other information is available, Partners should
                                               be very clear on  how price data is converted to
                                               physical or energy units. Price varies widely for
                                               a specific fuel, especially over the spatial and
                                               time frames typically established for reporting
                                               C02 emissions (e.g., entity wide reporting on an
                                               annual basis for Climate Leaders).

                                               If accurate records of fuel use are not available,
                                               the amount of fuel combusted can be deter-
                                               mined  using a bottom-up approach. The
                                               bottom-up method involves "building up" a fuel
                                               consumption estimate using vehicle activity
                                               data and fuel economy factors. Activity data
                                               could be in terms of vehicle miles traveled
                                               (VMT), freight ton-miles, passenger-miles, etc.
                                               This activity data can be multiplied by the
                                               appropriate fuel economy factors (e.g.,  gal-
                                               lons/mile) to generate an estimate of gallons of
                                               fuel consumed. This gallons estimate is then
                                               multiplied by the appropriate fuel-specific
                                               emission factor to  obtain an emissions esti-
                                               mate. Equation 5 outlines the bottom-up
                                               approach to estimating fuel use:
i o
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  Mobile  Combustion  Sources  —  Guidance
     Equation 5:  Bottom-up
 Approach to Estimating  Fuel
                   Use

Fuel Use = DT x FE
where:
DT  =  Distance Traveled Activity Factor
FE   =  Fuel Economy Factor
Note: the units for the fuel economy factor depend on the type of
  distance traveled activity data known (e.g., fuel economy factor
  of gallons per ton-mile if ton-miles activity data given).

If the bottom-up approach is used for gasoline
fueled highway vehicles, distance traveled
activity data by vehicle type are necessary.
These data should be available from records of
odometer readings or other travel records. The
preferred method for estimating data on fuel
economy for gasoline fueled highway vehicles
is to use company records by specific vehicle.
This includes the miles per gallon (mpg) values
listed on the sticker when the vehicle was pur-
chased or other company fleet records. If
sticker fuel economy values are not available
the recommended approach is to use fuel econ-
omy factors from the website,
www.fueleconomy.gov. This  website, operated
by the U.S.  Department of Energy and the U.S.
Environmental Protection Agency, lists city,
highway, and combined fuel economies by
make, model, model year, and specific engine
type. Current year as well as historic model
year data is available.

Notes on use of the fueleconomy.gov website
of estimate fuel economy values for use in
Climate  Leaders:

•  The default recommended approach is to use
   the combined city and highway mpg value for
   Partner specific vehicle or closest representa-
   tive vehicle type (needs to be converted to
   gallons per mile for use in Equation 5).

•  The fuel economy values listed for older
   vehicles were calculated when the vehicle
   was new. Over time the fuel economy could
   decline but that is not considered to be sig-
   nificant for use in Climate Leaders given
   other uncertainties around use of the data.

•  The website also lists estimated GHG emis-
   sions, but these are projected emissions
   based on an average vehicle miles traveled
   per year.  These are not likely to be accurate
   estimates for fleet vehicles, and are not
   acceptable estimates for  the purpose of the
   Climate Leaders Program.

If the bottom-up approach is used for heavy-
duty diesel fueled highway vehicles or diesel
fueled non-road vehicles,  activity data could
come in different forms. For some types of
vehicles, activity data could be represented  in
terms of distance traveled, for others it could
be represented by hours or  horsepower-hours
of operation or, for some, it  could be by ton-
miles shipped. This  activity data should be
available from company records. Specific infor-
mation on fuel consumed per unit of activity
data may be available from vehicle suppliers,
manufactures, or in  company records. If no
company specific information is available, the
default fuel economy values given in Table 4
can be used.

For freight transport, Partners should be par-
ticularly aware of any long duration idling.
Idling can generate significant carbon emis-
sions, and anti-idling strategies can be a
cost-effective strategy to reduce emissions. If
the top-down approach is used, the fuel related
to idling is accounted for  in the calculation. If
the bottom-up approach is used, partners
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                                       Mobile  Combustion  Sources  —  Guidance
              should be aware of and document the time
              spent (i.e., hours) idling and make sure it is
              included it in their calculations of C02
              emissions.

              If the bottom-up approach is used for air trans-
              port, activity data on distance traveled should
              be available  in company travel records. Specific
              information on fuel consumed per unit of dis-
              tance may be available from aircraft
              manufacturers or in company records. If no
              company specific information is available the
              default fuel economy values given in Table 4
              can be used.

              If the bottom-up approach is used for water-
              borne transport or rail transport, activity data
              could be respresented in terms of distance
              traveled or ton-miles shipped. Activity data val-
              ues should be available from company records.
              Data on average fuel consumed per unit of
              activity data should be available in company
              records, including original purchase records. If
                                                   no company specific information is available
                                                   the default fuel economy values given in Table
                                                   4 can be used.

                                                   The default values of BTU/Ton-Miles can be
                                                   converted to emissions by assuming a specific
                                                   type of fuel used based on the Partners opera-
                                                   tions. Furthermore, company specific factors
                                                   can also be used where appropriate.

                                                   For C02 emissions, the top-down approach of
                                                   estimating  fuel use is preferred over the bot-
                                                   tom-up approach, with the exception of
                                                   top-down data based on the dollar amount
                                                   spent on fuel. If accurate data is known on dis-
                                                   tance traveled and fuel economy for specific
                                                   vehicle types this is preferred over using fuel
                                                   price data.  If C02 emissions from a Partner's
                                                   mobile sources are a significant part of a
                                                   Partner's total GHG inventory, the top-down
                                                   approach should be used to calculate C02
                                                   emissions from those mobile sources.
                         Table 4:  Fuel  Economy Values by Vehicle  Type
              Vehicle Type
                                       Fuel Economy
                                       (Gallons per Mile)
Fuel Economy
(BTU/Ton-Mile)
              Diesel Highway Vehicles
                  Combination Trucks
                  Buses

              Waterborne
                  Domestic Commerce

              Air Travel (Jet Fuel, Kerosene)
                  Domestic Carriers
              Rail
                  Domestic Freight
                                            0.1887
                                            0.1449
                                             2.47
                                             352
    3,200
                                                                   508
              Sources: Diesel highway vehicles gallons per mile data from U.S. Department of Transportation, Federal Highway Administration,
                Highway Statistics 2000, Table VM-1. All other values from Oak Ridge National Laboratory, Transportation Energy Data Book:
                Edition 22 - 2002.
1 2
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  Mobile  Combustion  Sources  —  Guidance

For N20 and CH4 emissions, the bottom-up
approach using vehicle miles traveled is the
preferred approach as CH4 and N20 emission
factors are based on miles driven and not gal-
lons of fuel used.

4.2.  Emission
Calculation  Factors
Once the amount of fuel combusted is deter-
mined, the next step in calculating C02
emissions is to determine how much  carbon is
in the fuel. As outlined in Section 2, this  can be
determined from fuel density and carbon frac-
tion directly,  or by heat content and carbon
content per unit of energy.

Furthermore, a fuel's carbon content is never
fully oxidized into C02 emissions through com-
bustion. A portion of the carbon always
remains in the form of ash or unburned carbon.
Consequently, it is necessary to use an oxida-
tion factor when calculating C02 emissions from
mobile combustion sources using either
method mentioned above. Oxidation factors to
account for unburned carbon can be found in
Appendix B. However, Partners can use their
own oxidation factors, if available, to better
represent the fuel properties and the combus-
tion device's operating characteristics. It is
important to note that there are also intermedi-
ate combustion products from mobile
combustion sources such as carbon monoxide
(CO) and hydrocarbons that may eventually get
oxidized into C02 in the atmosphere. The car-
bon oxidation factor does not account for
carbon in these intermediate combustion prod-
ucts, but only for the amount of carbon that
remains as ash, soot or  particulate matter.

After calculating a fuel's oxidized carbon con-
tent it is necessary to convert carbon into C02
emissions. A fuel's oxidized carbon is convert-
ed into C02 emissions by multiplying the
carbon emissions by the molecular weight
ratio of C02 to carbon (44/12).
Table 5: Factors for Gasoline and On-Road
Fuel Type
Gasoline
On-Road Diesel Fuel
Carbon Content
(kg C/gallon)
2.42
2.78
Fraction
Oxidized5
0.99
0.99
ccyc
ratio
(44/12)
(44/12)
Diesel Fuel
Carbon Emission
Factor
(kg CCygallon)
8.79
10.08
Sources: Carbon content from 40 CFR 600.113 as shown in Appendix B6. Fraction oxidized from the 2002 Inventory of U.S. Greenhouse
  Gas Emissions and Sinks as shown in Appendix B. Carbon emission factors in terms of kg C02/gallon were calculated based on the
  other values given in Table 5.
5 The U.S. EPA Inventory of Greenhouse Gas Emissions and Sinks uses a fraction of carbon oxidized factor of 0.99 for all oil and oil-
  based products, as recommended by International Panel on Climate Change (IPCC) guidelines. Based on emissions data, EPA is
  currently examining whether this fraction is higher for motor vehicle fuels.
6 The U.S. EPA 2002 Inventory Greenhouse Gas Emissions and Sinks also provides factors for gasoline and on-road diesel fuel and
  yields values of 2.42 kg C/gallon for gasoline and 2.77 kg C/gallon for diesel fuel.
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                                       Mobile  Combustion  Sources  —  Guidance
              The most accurate method of determining how
              much carbon is in the fuel is through a fuel
              analysis. Fuel analysis provides the fuel density
              and fuel carbon fraction by weight. Factors are
              given in Table 5 for gasoline and on-road diesel
              fuel because they are the most commonly used
              mobile source fuels and their fuel properties
              are generally consistent.

              Partners can use more specific values than
              those given in Table 5, if available. For exam-
              ple, if they have data on specific gasoline used
              in terms of winter or summer grades and oxy-
              genated vs. non-oxygenated fuels, or other
              local fuel characteristics.

              For other fuels (e.g., off-road diesel fuel and
              fuel used for locomotive, rail or marine trans-
              port) there is not as much consistency and
              Partners should get specific information on
              fuel properties. If no information is available,
              Appendix B provides default factors for other
              fuel types.
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  Mobile  Combustion  Sources  —  Guidance

Completeness
   In order for a Partner's GHG corporate
   inventory to be complete it must include
   all emission sources within the company's
chosen inventory boundaries. See Chapter 3 of
the Climate Leaders Design Principles for
detailed guidance on setting organizational
boundaries and Chapter 4 of the Climate
Leaders Design Principles for detailed guidance
on setting operational boundaries of the corpo-
rate inventory.

On an organizational level the inventory should
include emissions from all applicable facilities
or fleets of vehicles. Completeness of corpo-
rate wide emissions can be checked by
comparing the list of sources included in the
GHG emissions inventory with those included
in other emission's inventories/environmental
reporting, financial reporting, etc.

At the operational level, a Partner should
include all GHG emissions from the sources
included in their corporate inventory. Possible
GHG emission sources are stationary fuel com-
bustion, combustion of fuels in mobile sources,
purchases of electricity, HFC emissions from
air conditioning equipment and process or
fugitive related emissions. Partners should
refer to this guidance document for calculating
emissions from mobile source fuel combustion
and to the Climate Leaders Core Guidance doc-
uments for calculating emissions from other
sources. For example, the calculation of HFC
and PFC emissions from mobile source air con-
ditioning equipment is described in the Climate
Leaders guidance tor Direct HFC and PFC
Emissions from Use of Refrigeration & Air
Conditioning Equipment.

As described in Chapter 1 of the Climate
Leaders Design Principles, there is no materiali-
ty threshold set for reporting emissions. The
materiality of a source can only be established
after it has been assessed. This does not nec-
essarily require a rigorous quantification of all
sources, but at a minimum, an  estimate based
on available data should be developed for all
sources.

The inventory should also accurately reflect
the timeframe of the report. In  the case of
Climate Leaders, the emissions inventory is
reported annually and should represent a full
year of emissions data.
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                                    Mobile  Combustion  Sources  —  Guidance
             Uncertainty  Assessment
                    There is uncertainty associated with all
                    methods of calculating C02 emissions
                    from mobile combustion sources. As
             outlined in Chapter 7 of the Climate Leaders
             Design Principles, Climate Leaders does not
             require Partners to quantify uncertainty as +/-
             % of emissions estimates or in terms of data
             quality indicators.

             It is recommended that Partners attempt to
             identify the areas of uncertainty in their emis-
             sions estimates and make an effort to use the
             most accurate data possible. The accuracy of
             estimating emissions  from fossil fuel combus-
             tion in mobile sources is partially determined
             by the availability of data on the amount of fuel
             consumed or purchased. If the amount of fuel
             combusted is directly measured or metered,
             then the resulting uncertainty should be fairly
                                                low. Data on the quantity of fuel purchased
                                                should also be a fairly accurate representation
                                                of fuel combusted, given that any necessary
                                                adjustments are made for changes in fuel
                                                inventory, fuel used as feedstock, etc. However,
                                                uncertainty may arise if only dollar value of
                                                fuels purchased is used to estimate fuel con-
                                                sumption. If the bottom-up method is used to
                                                determine fuel use, uncertainty may arise if
                                                estimates of distance traveled and/or fuel
                                                economies are roughly estimated.

                                                The accuracy of estimating emissions from
                                                mobile combustion sources is  also determined
                                                by the factors used to convert fuel use into
                                                emissions. Uncertainty in the factors is primari-
                                                ly due to the accuracy in which they are
                                                measured, and the variability of the supply
                                                source.
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Reporting   and   Documentation
       Partners are required to complete the
       Climate Leaders Reporting Requirements
       for mobile combustion and report annu-
al corporate level emissions. In order to ensure
that estimates are transparent and verifiable,
the documentation sources listed in Table 6
                                              should be maintained. These documentation
                                              sources should be collected to ensure the accu-
                                              racy and transparency of the related emissions
                                              data, and should also be reported in a Partner's
                                              Inventory Management Plan (IMP).
    Table  6: Documentation  Sources for  Mobile Combustion
Type
             Top-down
                                     Documentation Source
                                                  Bottom-up
Highway
Vehicles
Air Transport
Waterborne
Transport
             Fuel receipts; or                         Official odometer logs or other records of vehicle
             Fuel expenditure records; or               miles of travel (must be given by vehicle type); and
             Direct measurement records, including official Company fleet records, showing data on fuel
             logs of vehicle fuel gauges or storage tanks.   economy by vehicle type; or
                                                  Vehicle manufacturer documentation showing
                                                  fuel economy by vehicle type.
             Fuel receipts; or                         Company records of fuel consumed per unit-of-
             Fuel expenditure records; or               distance  traveled; or
             Direct measurement records, including official Aircraft manufacturer records of fuel consumed
             logs of vehicle fuel gauges or storage tanks.   per unit-of-distance traveled.
             Fuel receipts; or
             Fuel expenditure records; or
             Direct measurement records, including official
             logs of vehicle fuel gauges or storage tanks.
N/A
                                                  N/A
Rail Transport  Fuel receipts;or
             Fuel expenditure records; or
             Direct measurement records, including official
             logs of vehicle fuel gauges or storage tanks.
All Sources    If emission factors are customized, records of calorific values and/or carbon content of fuels; or
             Receipts or other records indicating location of fuel purchases.
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                                Mobile Combustion  Sources — Guidance
            Inventory  Quality  Assurance  and
            Quality  Control  (QA/QC)
                  Chapter 7 of the Climate Leaders Design
                  Principles provides general guidelines
                  for implementing a QA/QC process for
            all emission estimates. For mobile combustion
            sources, activity data and emission factors can
            be verified using a variety of approaches:

            • Fuel energy use data can be compared with
              data provided to Department of Energy or
              other EPA reports or surveys.

            • If any emission  factors were calculated or
              obtained from the fuel supplier, these fac-
              tors can be compared to U.S. average
              emission factors.
                                            Partners should review all activity data
                                            (e.g., fuel consumption data, distance trav-
                                            eled estimates), as well as any information
                                            used to develop customized emission fac-
                                            tors (e.g., location of fuel purchases,
                                            "cruising" aircraft fuel consumption).

                                            Fuel use calculations can be checked
                                            through a comparison of the bottom-up and
                                            top-down approaches.

                                            Cross checks using back-calculation of fuel
                                            economy can highlight order-of-magnitude
                                            errors.
1 8
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  Mobile  Combustion  Sources  —  Guidance

Appendix  A:  Calculating  CH4
and  N2O  Emissions  from  Mobile
Combustion  Sources
T
       he U.S. EPA's report U.S. Greenhouse
       Gas Emissions and Sinks7 provides a
       summary of tests that have been per-
formed to determine CH4 and N20 emissions
from mobile sources. The report states that
emissions of N20 from mobile sources have not
been extensively studied and are currently not
well characterized. The limited number of stud-
ies that have been performed on highway
vehicle emissions have shown that N20 emis-
sions are generally greater from vehicles with
catalytic converter systems than those without
such controls, and  greater from aged than from
new catalysts.

Annex E of the EPA report lists CH4 and N20
emission factors by different  types of highway
vehicles and control technologies (see Table
A-l, which is identical to Table 2 in Section 3).
Also listed is the percent of the different con-
trol technologies installed by model year of
vehicle (see Tables A-2 through A-5). These two
sources can be combined to determine CH4 and
N20 emission factors by model year of vehicle
as shown in Table 3 of Section 3.

CH4 emission factors were primarily obtained
from the IPCC8, which were derived from the
EPA's MOBILESa mobile source emissions
model9. The MOBILESa model uses information
on ambient temperature, diurnal temperature
range, altitude, vehicle speeds, national vehicle
registration distributions, gasoline volatility,
emission control technologies, fuel composi-
tion, and the presence or absence of vehicle
inspection/maintenance programs in order to
produce these factors. Since MOBILESa, many
heavy-duty gasoline vehicles are now compli-
ant with EPA Tier 1 and LEV emission
standards. Methane emission factors for these
vehicles were determined using emission fac-
tors from the California Air Resources Board10.

In order to better characterize the process by
which N20 is formed by catalytic controls and
to develop a more accurate national emission
estimate, the EPA's Office of Transportation
and Air Quality—at its National Vehicle and
Fuel Emissions Laboratory (NVFEL)—conduct-
ed a series of tests in order to measure
emission rates of N20 from used Tier 1 and LEV
gasoline-fueled passenger cars and light-duty
trucks equipped with catalytic converters.
These tests11 and a review of the literature
were used to develop the emission factors for
N20. The following references were used in
developing the N20 emission factors for gaso-
line-fueled highway passenger cars presented
in Table A-l:
7 U.S. EPA 2004 Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2002, EPA430-R-04-003, April 2004.
8 Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories, Paris: Intergovernmental Panel on Climate Change, United
  Nations Environment Programme, Organization for Economic Co-Operation and Development, International Energy Agency.
9 EPA Mobile Source Emission Factor Model (MOBILESa). Office of Mobile Sources, U.S. Environmental Protection Agency. Ann Arbor,
  Michigan.
10 Public Meeting to Consider Approval of Revisions to the State's On-road Motor Vehicle Emissions Inventory: Technical Support
  Document. California Air Resources Board, California Environmental Protection Agency, May 2000.
11 Emissions of Nitrous Oxide from Highway Mobile Sources: Comments on the Draft Inventory of U.S. Greenhouse Gas Emissions and
  Sinks, 1990-1996. U.S. EPA Office of Mobile Sources, Assessment and Modeling Division, August, EPA420-R-98-009. (Available on the
  internet at .)
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                                          Mobile  Combustion  Sources  —  Guidance
                •  LEVs: Tests performed at NVFEL12

                •  EPA Tier 1: Tests performed at NVFEL

                •  EPA Tier 0: Smith and Carey13, Barton and
                   Simpson14, and one car tested at NVFEL

                •  Oxidation Catalyst: Smith and Carey, Urban
                   and Garbe15

                •  Non-Catalyst: Prigent and de Soete16, Dasch17,
                   and Urban and Garbe

                Nitrous  oxide emission factors for other types
                of gasoline-fueled vehicles—light-duty trucks,
                heavy-duty vehicles, and motorcycles—were
                estimated by adjusting the factors for gasoline
                passenger cars, as described above, by their
                relative  fuel economies. This adjustment was
                performed using miles per  gallon data derived
                from:

                •  Transportation Energy Data Book (1993
                   through 2003), U.S. Department of Energy,
                   Office of Transportation Technologies,
                   Center for Transportation Analysis, Energy
                   Division, Oak Ridge National Laboratory,
                   ORNL-6959.
                                                        • Highway Statistics (1996 through 2003),
                                                           Federal Highway Administration, U.S.
                                                           Department of Transportation, Washington,
                                                           DC, report FHWA-PL-96-023-annual.

                                                        • Fuel Economy 2001 Datafile, U.S.
                                                           Environmental Protection Agency,
                                                           Department of Energy, Washington, DC,
                                                           dataset Olguide0918. (Available on the inter-
                                                           net at .)

                                                        • Vehicle Inventory and Use Survey, U.S.
                                                           Census Bureau, Washington, DC, database
                                                           CD-EC97-VIUS, January 2000.

                                                        Data from tests performed at NVFEL support
                                                        the conclusion that light-duty trucks and
                                                        other vehicles have higher emission rates
                                                        than passenger cars. However, the use of
                                                        fuel-consumption ratios to determine emission
                                                        factors is considered an estimate with a
                                                        moderate level of uncertainty.

                                                        Nitrous oxide emission factors for heavy-duty
                                                        gasoline vehicles compliant with EPA Tier 1
                                                        and LEV emissions  standards were estimated
               12 LEVs are assumed to be operated using low-sulfur fuel (i.e., Indolene at 24 ppm sulfur). All other NVFEL tests were performed using
                 a standard commercial fuel (CAAB at 285 ppm sulfur). Emission tests by NVFEL have consistently exhibited higher N,0 emission
                 rates from higher sulfur fuels on EPA Tier 1 and LEV vehicles.
               13 Smith, Lawrence R. and Penny M. Carey, Characterization of exhaust emissions from high mileage catalyst-equipped automobiles,
                 Society of Automotive Engineers, SAE Paper 820783.
               14 Barton, Peter and Jackie Simpson, The effects of aged catalysts and cold ambient temperatures on nitrous oxide emissions, Mobile
                 Source Emissions Division (MSED), Environment Canada, MSED Report #94-21.
               15 Urban, Charles M. and Robert J. Garbe, Exhaust Emissions from Malfunctioning Three-Way Catalyst-Equipped Automobiles, Society of
                 Automotive Engineers, SAE Paper 800511.
               16 Prigent, Michael and Gerard De Soete, Nitrous oxide (Nf>) in engines exhaust gases-a first appraisal of catalyst impact, Society of
                 Automotive Engineers, SAE Paper 890492.
               17 Dasch, Jean Muhlbaler, Journal of the Air and Waste Management Association, "Nitrous Oxide Emissions from Vehicles," 42(l):63-67,
                 January.
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from the ratio of NOX emissions to N20 emis-
sions for EPA Tier 0 heavy-duty gasoline trucks.
For EPA Tier 0 heavy-duty gasoline trucks, a
NOX to N20 ratio of 60 was found. This ratio
was applied to the NOX emissions from EPA
Tier 1 and LEV heavy-duty gasoline vehicles to
approximate N20 emissions from these control
technology classes for heavy-duty gasoline
vehicles.

The resulting N20  emission factors employed
for gasoline highway vehicles are  lower than
the U.S. default values presented in the Revised
1996IPCC Guidelines18, but are higher than the
European default values, both of which were
published before the more recent tests and lit-
erature review conducted by the NVFEL. The
U.S. defaults in the Revised 1996 IPCC
Guidelines were based on three studies that
tested a total of five cars using European
rather than U.S.  test procedures.

Nitrous oxide emission factors for diesel high-
way vehicles were taken from the European
default values found in the Revised 1996 IPCC
Guidelines, since little data addressing N20
emissions from U.S. diesel-fueled vehicles
exists.

Vehicle Miles Traveled by vehicle type for each
model year were distributed across various
control technologies as shown in Table A-2
through Table A-5. The categories "EPA Tier 0"
and "EPA Tier 1" were substituted for the early
three-way catalyst and advanced three-way cat-
alyst categories, respectively, as defined in the
Revised 1996 IPCC Guidelines. EPA Tier 0, EPA
Tier 1, and LEV actually refer to U.S. emission
regulations, rather than control technologies;
however, each does  correspond to particular
combinations of control technologies  and
engine design. EPA Tier 1  and its predecessor
EPA Tier 0 both apply to vehicles equipped
with three-way catalysts.  The introduction of
"early three-way catalysts," and "advanced
three-way catalysts," as described in the
Revised 1996 IPCC Guidelines, roughly corre-
spond to the introduction of EPA Tier  0 and
EPA Tier 1 regulations19.

Control technology assignments for light and
heavy-duty conventional  fuel vehicles for
model years  1972 (when regulations began to
take effect) through  1995  were estimated20.
Assignments for 1998 through 2001 were deter-
mined using confidential  engine family sales
data submitted to EPA21. Vehicle classes  and
emission standard tiers to which each engine
family was certified were  taken from annual
certification test results and data22. This was
used to determine the fraction of sales of each
class of vehicle that met EPA Tier 0, EPA Tier 1,
and LEV standards. Assignments for 1996 and
1997 were estimated based  on the fact that EPA
Tier 1 standards for  light-duty vehicles were
fully phased in by 1996.

Annex E of the EPA National Inventory report
also lists CH4 and N20 emission factors by dif-
ferent types of non-highway vehicles and for
alternate fueled vehicles.
18 Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories, Paris: Intergovernmental Panel on Climate Change, United
  Nations Environment Programme, Organization for Economic Co-Operation and Development, International Energy Agency.
19 Same as footnote 11.
20 Same as footnote 11.
21 Confidential engine family sales data submitted to EPA by manufacturers. Office of Transportation and Air Quality, U.S.
  Environmental Protection Agency.
22 Annual Certification Test Results Report. Office of Transportation and Air Quality, U.S. Environmental Protection Agency. (Available
  on the internet at .)
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                                         Mobile  Combustion  Sources  —  Guidance
               Table A-1: CH4 and N2O Emission Factors for Highway Vehicles
               Vehicle Type/Control Technology
                                            Emission Factor
                                            (Grams per mile)
                                                        CH4
N2O
Emission Factor
(Grams per km)
N2O       CH4
Gasoline Passenger Cars
Low Emission Vehicles
Tier 1
TierO
Oxidation Catalyst
Non-Catalyst
Uncontrolled
Gasoline Light-Duty Trucks
Low Emission Vehicles
Tierl
TierO
Oxidation Catalyst
Non-Catalyst
Uncontrolled
Gasoline Heavy-Duty Vehicles
Low Emission Vehicles
Tierl
TierO
Oxidation Catalyst
Non-Catalyst
Uncontrolled
Diesel Passenger Cars
Advanced
Moderate
Uncontrolled
Diesel Light Trucks
Advanced
Moderate
Uncontrolled
Diesel Heavy-Duty Vehicles
Advanced
Moderate
Uncontrolled
Motorcycles
Non-Catalyst Control
Uncontrolled

0.0283
0.0463
0.0816
0.0518
0.0166
0.0166

0.0355
0.058
0.1022
0.0649
0.0208
0.0208

0.1133
0.1394
0.2361
0.1499
0.048
0.048

0.0161
0.0161
0.0161

0.0322
0.0322
0.0322

0.0483
0.0483
0.0483

0.0073
0.0073

0.0402
0.0483
0.0644
0.1127
0.1931
0.2173

0.0483
0.0563
0.1127
0.1448
0.2253
0.2173

0.0708
0.0966
0.1207
0.1448
0.2012
0.4345

0.0161
0.0161
0.0161

0.0161
0.0161
0.0161

0.0644
0.0805
0.0966

0.2092
0.4184

0.0176
0.0288
0.0507
0.0322
0.0103
0.0103

0.022
0.0361
0.0635
0.0403
0.0129
0.0129

0.0704
0.0866
0.1467
0.0932
0.0298
0.0298

0.01
0.01
0.01

0.02
0.02
0.02

0.03
0.03
0.03

0.0045
0.0045

0.025
0.03
0.04
0.07
0.12
0.135

0.03
0.035
0.07
0.09
0.14
0.135

0.044
0.06
0.075
0.09
0.125
0.27

0.01
0.01
0.01

0.01
0.01
0.01

0.04
0.05
0.06

0.13
0.26
               Notes: The categories "Tier 0" and "Tier 1" were substituted for the early three-way catalyst and advanced three-way catalyst cate-
                 gories, respectively, as defined in the Revised 1996 IPCC Guidelines. Methane emission factor for gasoline heavy duty trucks with
                 oxidation catalyst assumed based on light-duty trucks oxidation catalyst value.
22
CLIMATE LEADERS  GHG  INVENTORY PROTOCOL

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Mobile
Combust
ion Sources — Gu


Table A-2: Control Technology Assignments for
Gasoline Passenger Cars (Percent VMT)
Model Years
1973-1974
1975
1976-1977
1978-1979
1980
1981
1982
1983
1984-1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
Non-catalyst
100%
20%
15%
10%
5%
-
-
-
-
-
-
-
-
-
-
-
-
-
Oxidation
-
80%
85%
90%
88%
15%
14%
12%
-
-
-
-
-
-
-
-
-
-
TierO
-
-
-
-
7%
85%
86%
88%
100%
60%
20%
1%
0.5%
0.01%
0.01%
-
-
-
Tier 1
-
-
-
-
-
-
-
-
-
40%
80%
97%
96.5%
87%
67%
44%
3%
1%
LEV
-
-
-
-
-
-
-
-
-
-
-
2%
3%
13%
33%
56%
97%
99%
Table A-3: Control Technology Assignments for
Gasoline Light-Duty Trucks (Percent VMT)
Model Years
1973-1974
1975
1976
1977-1978
1979-1980
1981
1982
1983
1984
1985
1986
1987-1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
Non-catalyst
100%
30%
20%
25%
20%
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Oxidation
70%
80%
75%
80%
95%
90%
80%
70%
60%
50%
5%
-
-
-
-
-
-
-
-
-
TierO
-
-
-
-
5%
10%
20%
30%
40%
50%
95%
60%
20%
-
-
-
-
-
-
-
Tier 1
-
-
-
-
-
-
-
-
-
-
-
40%
80%
100%
100%
80%
57%
65%
1%
10%
LEV
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
20%
43%
35%
99%
90%
CLIMATE  LEADERS GHG  INVENTORY  PROTOCOL
23

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                                    Mobile  Combustion Sources  — Guidance
                      Table A-4: Control  Technology Assignments for
                        Gasoline Heavy-Duty Vehicles (Percent VMT)
Model Years
<1981
1982-1984
1985-1986
1987
1988-1989
1990-1995
1996
1997
1998
1999
2000
2001
2002
Uncontrolled Non-catalyst
100%
95%
95%
70%
60%
45%
-
-
-
-
-
-
-
Oxidation
-
5%
5%
15%
25%
30%
25%
10%
-
-
-
-
-
TierO
-
-
-
15%
15%
25%
10%
5%
-
-
-
-
-
Tier 1
-
-
-
-
-
-
65%
85%
96%
78%
54%
64%
69%
LEV
-
-
-
-
-
-
-
-
4%
22%
46%
36%
31%
                      Table A-5: Control  Technology Assignments for
                             Diesel Highway and  Motorcycle VMT
                           Vehicle Type/Control Technology
                                                            Model Years
                           Diesel Passenger Cars and Light-Duty Trucks
                               Uncontrolled                           1966-1982
                               Moderate control                       1983-1995
                               Advanced control                       1996-2002
                           Heavy-Duty Diesel Vehicles
                               Uncontrolled                           1966-1982
                               Moderate control                       1983-1995
                               Advanced control                       1996-2002
                           Motorcycles
                               Uncontrolled                           1966-1995
                               Non-catalyst controls                    1996-2002
             For non-highway vehicles, the CH4 and N20
             emission factors are given in terms of mass of
             emissions per mass of fuel combusted. Table A-
             6 shows the default CH4 and N20 emission
             factors for non-highway vehicles by vehicle
             and fuel type. For alternate fueled vehicles, the
             CH4 and N20 emission factors are given in
             terms of mass per miles (or km) driven. Table
             A-7 shows the default CH4 and N20 emission
             factors for alternate fueled vehicles by vehicle
             and fuel type.
                                               The emissions for highway vehicles, listed in
                                               Table A-l and Table 3 of Section 3, can be used
                                               to estimate emissions based on miles driven
                                               (bottom-up approach) for the different cate-
                                               gories of vehicles. The values provided in
                                               Table A-6 can be used to estimate emissions
                                               from non-highway vehicles based on total fuel
                                               used. Furthermore, company specific factors
                                               can also be used where appropriate (e.g., if  dif-
                                               ferent fuel economy values are known, or if
                                               older model year vehicles are included).
24
CLIMATE  LEADERS  GHG INVENTORY PROTOCOL

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Mobile Combus
tion Sources —


Table A-6: CH4 and N2O Emission Factors for
Non-Highway Vehicles23
Vehicle Type/Fuel Type
Ships and Boats
Residual Fuel Oil
Diesel Fuel
Gasoline
Locomotives
Diesel Fuel
Agricultural Equipment
Gasoline
Diesel Fuel
Construction Equipment
Gas Construction
Diesel Construction
Other Non-Highway
Gas Snowmobiles
Gas Small Utility
Gas H-D Utility
Diesel H-D Utility
Source: U S. EPA 2004 Inventory of U.S.
Emission Factor
(Grams per Kg Fuel)
N2O CH4
0.08 0.23
0.08 0.23
0.08 0.23

0.08 0.25
0.08 0.45
0.08 0.45
0.08 0.18
0.08 0.18
0.08 0.18
0.08 0.18
0.08 0.18
0.08 0.18
Greenhouse Gas Emissions and Sinks:
Fuel Density Emission Factor
(kg/gal) (Grams per gal Fuel)
N2O CH4
3.58 0.29
3.19 0.26
2.79 0.22

3.19 0.26
2.79 0.22
3.19 0.26
2.79 0.22
3.19 0.26
2.79 0.22
2.79 0.22
2.79 0.22
3.19 0.26
1990-2002, EPA430-R-04-003.
0.82
0.73
0.64

0.80
1.26
1.44
0.50
0.57
0.50
0.50
0.50
0.57

Table A-7: CH4 and N2O Emission Factors for
Alternate Fueled Vehicles

Vehicle Type/Fuel Type
Light-duty Vehicles
Methanol
CNG
OEM LPG Vehicles
Retrofit LPG Vehicles
Ethanol
Heavy-duty Vehicles
Methanol
CNG
LNG
LPG
Ethanol
Buses
Methanol
CNG
Ethanol
Source: U S. EPA 2004 Inventory of U.S.
Emission Factor
(Grams per mile)
N2O CH4
0.063 0.014
0.113 0.914
0.00756 0.0381
0.295 1.180
0.076 0.043
0.217 0.646
0.297 9.629
0.440 6.857
0.150 0.108
0.307 1.975

0.217 0.646
0.162 12.416
0.364 2.079
Greenhouse Gas Emissions and Sinks:
Emission Factor
(Grams per km)
N2O CH4
0.039 0.009
0.070 0.568
0.0047 0.0237
0.183 0.733
0.047 0.027
0.135 0.401
0.185 5.983
0.274 4.261
0.093 0.067
0.191 1.227

0.135 0.401
0.101 7.715
0.226 1.292
1990-2002, EPA430-R-04-003.

















23 Factors for Aviation have been excluded from the table due to uncertainties in the factors.
                                      CLIMATE  LEADERS  GHG  INVENTORY  PROTOCOL
25

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                                      Mobile  Combustion  Sources  —  Guidance
              Appendix  B:  Calculating  CO2
              Emissions  from   Mobile
              Combustion   Sources
              T
             his appendix contains factors for use in
             calculating C02 emissions for different
             types of transportation fuels.
              Motor  Gasoline and
              Diesel  Fuel
              Factors for motor gasoline and diesel fuel are
              presented in Table B-l from two different
              sources. The U.S. EPA National Inventory
              report24 provides values based on the energy
        content of the fuels. The Code of Federal
        Regulations (CFR)25 provides values based on
        the carbon content of the fuel and fuel density
        for each fuel type.
        EPA recommends that Climate Leaders
        Partners use 8.79 kg C02/gallon for motor
        gasoline and 10.08 kg C02/gallon for diesel fuel
        as default factors which are provided in Table
        5 of Section 4.2.
                   Table  B-1:  Factors for Calculating CO2  Emissions from
                                Motor Gasoline and Diesel Fuel  Use
              Fuel / Source
                               Heat
                             Content
                              (HHV)
                          (MMBtu/BarreO
   Carbon
   Content       Carbon                Emission
 Coefficient       Factor     Fraction     Factor
(kg C/MMBtu)   (kg C/gallon)  Oxidized26 (kg CO2/gal.)
Motor Gasoline:
U.S. EPA Inventory 5.253
CFR
Diesel Fuel:
U.S. EPA Inventory 5.825
CFR

19.34 2.42
2.42

19.95 2.77
2.78

0.99
0.99

0.99
0.99

8.78
8.79

10.04
10.08
              Note: Values for fuels may change over time so it is recommended that Partners update factors on a regular basis. Factors shown here
                are appropriate for years 2000-2004.
              Sources: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990 - 2002, EPA430-R-04-003, U.S. Environmental Protection Agency,
                Washington, DC April 2004. Heat Contents, and Carbon Content Coefficients from Annex 2. Carbon Factors (kg C/gallon) calculated
                by multiplying Heat Contents by Carbon Content Coefficients and then dividing by 42 gallons per barrel.
                Code of Federal Regulations (CFR) 40 CFR 600.113-78. The CFR gives carbon content values of 2,421 g C/gallon for gasoline and
                2,778 g C/gallon for diesel fuel. These values are converted to kg C/gallon and shown in Table B-l as Carbon Factors.
                Fractions Oxidized from Annex 2 of EPA inventory report. Emission Factors (kg C02/gallon) calculated by multiplying Carbon
                Factors by Fractions Oxidized and then multiplying by the CO,/C ratio of 44/12.
              24 Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990 - 2002, EPA 430-R-04-003, U.S. Environmental Protection Agency,
                Washington, DC April 2004.
              25 Code of Federal Regulations (CFR) 40 CFR 600.113-78.
              26 The U.S. EPA Inventory of Greenhouse Gas Emissions and Sinks uses a fraction of carbon oxidized factor of 0.99 for all oil and oil-
                based products, as recommended by International Panel on Climate Change (IPCC) guidelines. Based on emissions data, EPA is
                currently examining whether this fraction is higher for motor vehicle fuels.
26
CLIMATE  LEADERS GHG INVENTORY  PROTOCOL

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  Mobile  Combustion  Sources  —  Guidance

          Oj|  Aviation
    factors were taken from the U.S. EPA
National Inventory reP°rt based on the ener§y
Gasoline   and Jet  Fuel
                                               content of the fuels.
Factors for residual fuel oil (#5 & 6), aviation
gasoline, and jet fuel are presented in Table B-2.


     Table B-2:  Factors for Calculating CO2 Emissions from
             Fuel Oil, Aviation Gasoline,  and Jet Fuel Use

                           Heat           Carbon
                          Content         Content       Carbon                 Emission
                          (HHV)         Coefficient      Factor      Fraction      Factor
Fuel /Source         (MMBtu/Barrel)  (kg C/MMBtu)  (kg C/gallon)  Oxidized  (kg CO2/gal.)

Residual Fuel Oil (#5 & 6)   6.287             21.49          3.22         0.99        11.68

Aviation Gasoline           5.048             18.87          2.27         0.99         8.23

Jet Fuel                    5.670             19.33          2.61         0.99         9.47

Note: Values for fuels may change over time so it is recommended that Partners update factors on a regular basis. Factors shown here
  are appropriate for years 2000-2004.
Sources: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990 - 2002, EPA430-R-04-003, U.S. Environmental Protection Agency,
  Washington, DC April 2004. Heat Contents, Carbon Content Coefficients, and Fractions Oxidized from Annex 2. Carbon Factors (kg
  C/gallon) calculated by multiplying Heat Contents by Carbon Content Coefficients and then dividing by 42 gallons per barrel.
  Emission Factors (kg C02/gallon) calculated by multiplying Carbon Factors by Fractions Oxidized and then multiplying by the
  COp/C ratio of 44/12.
                            CLIMATE  LEADERS  GHG INVENTORY PROTOCOL  •  27

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                                          Mobile  Combustion   Sources  —  Guidance
                Liquefied  Petroleum
                Gas  (LPG)
                Factors for LPG and LPG components are pre-
                sented in Table B-3. The factors for LPG were
                based on the physical characteristics of LPG
                components and an assumed LPG composition.
                                                        If a Partner knows the specific blend of LPG
                                                        that they are using in their mobile sources
                                                        which could include any of the components
                                                        listed in Table B-3, heat content and carbon
                                                        content coefficients for different blends of LPG
                                                        can be calculated based on the percent mix
                                                        and individual component characteristics
                                                        shown in Table B-3.
                     Table B-3:  Factors  for Calculating  CO2  Emissions from
                                                         LPG Use
               Fuel / Source
                                   Heat            Carbon
                                 Content          Content        Carbon                  Emission
                                  (HHV)         Coefficient      Factor      Fraction     Factor
                             (MMBtu/Barrel)   (kg C/MMBtu)  (kg C/gallon)  Oxidized  (kg CO2/gal.)
               LPG                        3.849
               Common LPG Components:
                                                    17.23
1.58
0.995
5.76
Ethane
Propane
Isobutane
n-Butane
2.916
3.824
4.162
4.328
16.25
17.20
17.75
17.72
1.13
1.57
1.76
1.83
0.995
0.995
0.995
0.995
4.12
5.71
6.42
6.67
               Note: Values for fuels may change over time so it is recommended that Partners update factors on a regular basis. Factors shown here
                 are appropriate for years 2000-2004.
               Sources: Heat Contents and Carbon Content Coefficients for LPG components from Annex 2 of Inventory of U.S. Greenhouse Gas
                 Emissions and Sinks: 1990 - 2002, EPA430-R-04-003, U.S. Environmental Protection Agency, Washington, DC April 2004. Heat Content
                 and Carbon Content Coefficient for LPG are based on a LPG composition of 95% Propane and 5% n-Butane by volume. This is an
                 assumed composition for mobile source LPG taken from the Code of Federal Regulations (CFR) 40 CFR Part 86, Appendix XVI, 7-1-01
                 edition. Heat Content for LPG based on a weighted average volume percent (95% Propane and 5% n-Butane), Carbon Content
                 Coefficient for LPG based on a weighted average energy percent (94.4% Propane and 5.6%  n-Butane).
                 Carbon Factors (kg C/gallon) calculated by multiplying Heat Contents by Carbon Content Coefficients and then dividing by 42 gal-
                 lons per barrel. Fractions Oxidized from Annex 2 of EPA inventory report, Fractions Oxidized for LPG components assumed to be
                 the same as for LPG. Emission Factors (kg C02/gallon) calculated by multiplying Carbon Factors by Fractions Oxidized and then
                 multiplying by the C02/C ratio of 44/12.
28
CLIMATE  LEADERS  GHG  INVENTORY  PROTOCOL

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  Mobile   Combustion  Sources  —  Guidance

Natural  Gas
(Compressed  and
Liquefied)
Natural gas can be used as a mobile source fuel
in a compressed or liquefied form. Factors for
compressed natural gas are presented in Table
B-4 based on the energy content of the fuel.
Factors for liquefied natural gas are presented
in Table B-5 based on the carbon content of the
fuel.
      Table  B-4:  Factors  for  Calculating  CO2 Emissions from
                          Compressed  Natural Gas  Use


Fuel / Source
Natural Gas
(compressed)
Heat
Content
(HHV)
(Btu/Standard
Cu. Ft.)
1,027


Carbon
Content
Coefficient
(kg C/MMBtu)
14.47


Carbon
Factor
(kg C/Standard
Cu. Ft.)
0.015



Fraction
Oxidized
0.995


Emission
Factor
(kg CO2/Standard
Cu. Ft.)
0.054

Note: Values for fuels may change over time so it is recommended that Partners update factors on a regular basis. Factors shown here
  are appropriate for years 2000-2004.
Sources: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990 - 2002, EPA430-R-04-003, U.S. Environmental Protection Agency,
  Washington, DC April 2004. Heat Content, Carbon Content Coefficient, and Fraction Oxidized from Annex 2. Carbon Factor (kg
  C/Standard Cu. Ft.) calculated by converting Heat Content from Btu/Standard Cu. Ft. to MMBtu/ Standard Cu. Ft. and then multiply-
  ing by Carbon Content. Emission Factor (kg C02/Standard Cu. Ft.) calculated by multiplying Carbon Factor by Fraction Oxidized
  and then multiplying by the C02/C ratio of 44/12.
  Note: Values in Table B-4 are presented in terms of standard cu. ft., Partners should express natural gas use in terms of standard
  cu. ft. in order to use the factors in Table B-4.
      Table  B-5:  Factors  for  Calculating  CO2 Emissions from
                             Liquefied  Natural  Gas Use
Fuel / Source
Natural Gas (liquefied)
Carbon
Factor
(kg C/gallon)
1.62
Fraction
Oxidized
0.995
Emission
Factor
(kg C02/gal.)
5.91
Note: Values for fuels may change over time so it is recommended that Partners update factors on a regular basis. Factors shown here
  are appropriate for years 2000-2004.
Sources: The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model, Argonne National Laboratory,
  Transportation Technology R&D Center, available at http://www.transportation.anl.gov/greet/. GREET model provides Carbon
  Factor in terms of g C/gallon of fuel. That value is converted to kg C/gallon and shown in Table B-5 as Carbon Factor. Fraction
  Oxidized from Annex 2 of EPA inventory report, assumed to be the same as natural gas. Emission Factor (kg C02/gallon) calculated
  by multiplying Carbon Factor by Fraction Oxidized and then multiplying by the C02/C ratio of 44/12.
  Note: The GREET Factors are from the fuel specifications section of the model. The GREET model calculates life cycle emissions
  but the factors presented in Table B-5 only represent fuel combustion emissions. This is consistent with the other factors present-
  ed in this guidance.
                               CLIMATE  LEADERS  GHG  INVENTORY  PROTOCOL
                                                             29

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                                          Mobile  Combustion  Sources  —  Guidance
                Ethanol
                Factors for ethanol are presented in Table B-6.
                The factors were taken from the U.S. EPA
                National Inventory report based on the energy
                content of the fuel. As per Section 1.3, emis-
                sions from  ethanol combustion are treated as
                biomass C02 and listed as supplemental infor-
                mation on a Partner's inventory report. The
                                                        values in Table B-6 represent 100% ethanol, if a
                                                        Partner is using E85, the activity data for E85
                                                        total fuel use (e.g., in gallons) would have to be
                                                        split into 85% ethanol and 15% gasoline. The
                                                        factors in Table B-6 would be used for the
                                                        ethanol portion of the fuel and the values in
                                                        Table B-l would be used for the gasoline por-
                                                        tion of the fuel.
                     Table  B-6: Factors for Calculating CO2 Emissions  from
                                                      Ethanol Use
                                            Heat            Carbon
                                          Content          Content       Carbon                  Emission
                                           (HHV)         Coefficient      Factor      Fraction      Factor
               Fuel/Source         (MMBtu/Barrel)   (kg C/MMBtu) (kg C/gallon)   Oxidized  (kg CO2/gal.)
               Ethanol
                                   3.539
17.99
1.52
0.99
5.50
               Note: Values for fuels may change over time so it is recommended that Partners update factors on a regular basis. Factors shown here
                 are appropriate for years 2000-2004.
               Sources: Heat content from the Annual Energy Review 2002, DOE/EIA-0384(2002), Energy Information Administration, U.S. Department
                 of Energy, Washington, DC October 2003, Appendix A. Carbon content coefficient from the Inventory of U.S. Greenhouse Gas
                 Emissions and Sinks: 1990 - 2002, EPA430-R-04-003, U.S. Environmental Protection Agency, Washington, DC April 2004, Chapter 3 text
                 describing the methodology used to calculate emissions from Wood Biomass and Ethanol Consumption. Carbon Factor (kg C/gal-
                 lon) calculated by multiplying Heat Content by Carbon Content Coefficient and then dividing by 42 gallons per barrel. Fraction
                 Oxidized from Annex 2 of EPA inventory report, assuming the same fraction oxidized for ethanol as for gasoline. Emission Factor
                 (kg C02/gallon) calculated by multiplying Carbon Factor by Fraction Oxidized and then multiplying by the C02/C ratio of 44/12.
3O
CLIMATE  LEADERS  GHG  INVENTORY  PROTOCOL

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  Mobile  Combustion  Sources  —  Guidance

Biodiesel
Factors for biodiesel are presented in Table B-
7. The factors are based on the carbon content
of the fuel. As per Section 1.3, emissions from
biodiesel combustion are treated as biomass
C02 and listed as supplemental information on
a Partner's inventory report. The values in
Table B-7 represent 100% biodiesel, if a Partner
is using B20, the activity data for B20 total fuel
use (e.g., in gallons) would have to be split into
20% biodiesel and 80% diesel fuel. The factors
in Table B-7 would be used for the biodiesel
portion of the fuel and the values in Table B-l
would be used for the diesel portion of the
fuel.
     Table  B-7:  Factors for  Calculating CO2 Emissions from
                                     Biodiesel Use
Fuel / Source
Biodiesel
Carbon
Factor
(kg C/gallon)
2.56
Fraction
Oxidized
0.99
Emission
Factor
(kg C02/gal.)
9.29
Note: Values for fuels may change over time so it is recommended that Partners update factors on a regular basis. Factors shown here
  are appropriate for years 2000-2004.
Sources: Carbon Factor from the draft report A Comprehensive Analysis of Biodiesel Impacts on Exhaust Emissions. Fraction Oxidized
  from Annex 2 of EPA inventory report, assumed the same as diesel fuel. Emission Factor (kg C02/gallon) calculated by multiplying
  Carbon Factor by Fraction Oxidized and then multiplying by the C02/C ratio of 44/12.
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SEPA
     United States
     Environmental Protection
     Agency

     Office of Air and Radiation (6202J)
     EPA430-K-03-005
     October 2004
     www.epa.gov/climateleaders

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