CDP Technical Note: Measuring emissions intensity oftransport movements
CDP Corporate QuestionnaireContentsVersion .......................................................................................................................................... 3
1.

2.

3.

Introduction ............................................................................................................................ 4
1.1

Why measure the emissions intensity of transportation? ................................................... 4

1.2

What does that mean for your CDP response? ................................................................. 4

1.3

Purpose of this document ................................................................................................. 4

1.4

Technical basis of this document ...................................................................................... 5

From absolute emissions to intensity metrics..................................................................... 6
2.1

Use cases for calculating and reporting emissions ............................................................ 6

2.2

Reporting emissions per ton-kilometer or passenger-kilometer ......................................... 6

Resources for calculating primary intensity metrics .......................................................... 9
3.1

Transport Services ............................................................................................................ 9

3.2

Transport OEMs ............................................................................................................. 10

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VersionVersion

Revision date

Revision summary

1.0
1.1

June 8, 2018
April 7, 2020

1.2

January 7, 2021

First published version
Question numbers updated to align with the 2020 CDP climatechange questionnaire.
Minor editorial changes

1.3

June 28, 2024

Question numbers updated to align with the CDP Corporate
Questionnaire 2024

Copyright © CDP Worldwide 2024
All rights reserved. Copyright in this document is owned by CDP Worldwide, a registered charity number1122330 and a company limited by guarantee, registered in England number 05013650.

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1. Introduction
1.1 Why measure the emissions intensity of transportation?
For transport service providers and transport original equipment manufacturers (OEMs), therecommended way to calculate and report transport emissions is by using both an absolute figure
and an intensity measurement. Absolute emissions are important, as this is the total emissions
figure that ultimately needs to be reduced to mitigate climate change. However, often this does notprovide sufficient information for the internal and external understanding of a company’sgreenhouse gas (GHG) efficiency. To that end, intensity metrics need to be used, which have thefollowing benefits: Intensity metrics provide insight into the GHG efficiency of an organization and thetransport movements that it owns or contracts. They enable the tracking of progress overtime and identify gaps and areas of action for increased mitigation effort within distinct andmulti-modal transport chains; Intensity metrics enable comparison between different modes of transport and allow for acomparison of efficiency against competitors.

1.2 What does that mean for your CDP response?
In practical terms for the transport sector, this implies measuring emissions per unit of goods or per
passenger transported, over a set distance, as expressed in tCO2e, per passenger or ton, perkilometer or mile (i.e. tCO2e/p.km - mile or tCO2e/t.km - mile). In the CDP Corporate Questionnaire,a primary intensity metric is required to respond to the following questions:7.51, where transport service companies are asked to report a primary intensity metricfor all transport movements carried out in the reporting year using light duty and heavy
duty vehicles (LDV and HDV), aircraft, marine ships and trains, to enable investors anddata users to make a comparison between organizations and the different transportmodes they are employing;7.50, where OEMs are asked to report a primary intensity metric for vehicles sold in thereporting year. This enables investors and data users to compare the performance ofvehicles with a similar purpose, as well as with policy and market trends. It should be
noted that this question only applies to final vehicle producers, not to component
manufacturers.

1.3 Purpose of this document
This technical note aims to familiarize the reader with the intensity metric as specified in sections
1.1 and 1.2 above. It explains the rationale behind the use of this metric and why CDP isrequesting it. It explains the numerator and denominator and refers to other relevant standards andresources. The technical note references the GLEC framework produced by the Smart Freight
Centre, which is a methodology that aims to unify emissions calculations for different goods andmodes into one standardized approach (see Box 1) 1.
The technical note is not a step-by-step guide on how to calculate freight emissions. For that,existing methodologies can be used, such as those detailed in the GLEC framework and in Table 1
1 Smart Freight Centre, “GLEC Framework for Logistics Emissions Methodologies, Version 1.0,” 2016,www.smartfreightcentre.org.
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below. Companies unfamiliar with reporting transportation emissions are encouraged to refer tothese standards to gather data and calculate their emissions. This technical note can then be used
to understand how this information can be converted to the right type of intensity metric forreporting in the CDP Corporate Questionnaire.
Only companies responding to the transport services and transport OEMs sector questions in
CDP’s Corporate Questionnaire are required to report transport-specific intensity metrics, and thisdocument will therefore be most useful to them. Other companies, such as shippers of goods, arealso invited to do so when they deem it relevant to their business in question 7.45 of the CDP
Corporate Questionnaire regarding emission intensities.

1.4 Technical basis of this document
The most important resource for this technical note is the framework produced by the GlobalLogistics Emissions Council (GLEC) 2. The base methodologies for this framework are shown inFigure 1.
GLEC Framework:
The GLEC framework comprises an industry-specific guidance document that is designed to work in
conjunction with the GHG Protocol. The framework presents a harmonized approach to calculating bothabsolute emissions and emission intensity across all transport modes in the CDP Corporate
Questionnaire (both for the transport sector specific questions, and Scope 3 emissions reporting
applicable to all companies). Wherever possible, the GLEC framework has aligned its approach toexisting sector methodologies that have already been developed and are widely used within the logistics
sector, as well as within global GHG accounting. Figure 1 shows the base methodologies that havebeen identified by GLEC as leading in terms of their consistency, usefulness and current widespread
acceptance and use.

Figure 1: Methodologies identified by GLEC as the basis for their measurement framework

2 Smart Freight Centre.

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2. From absolute emissions to intensity metrics
2.1 Use cases for calculating and reporting emissions
The calculation of emissions from transportation can be used in several ways.
 Corporate carbon footprint: Having information on total fuel use and emissions within thetransport chain can be totaled and used as part of the company’s Scope 1, 2 and 3
footprints. Reporting emissions from transportation is common practice for most sectors
corporate carbon footprints. Transportation is one of the more accessible and established
Scope 3 categories to calculate total emissions for;
 Life cycle assessment: Information on transport emissions is key to undertaking life cycle
assessments to acquire information for carbon footprints at the product level. Life cycle
assessments require more detailed information on the type of transport used, as well as
information on distance and load factors. The CDP Corporate Questionnaire does not
request specific information on product-level emissions, therefore this technical note will notfurther expand on this use-case; GHG efficiency of transportation: As explained in section 1.1, intensity metrics capture
more relevant information that can be used to benchmark performance and improve
efficiency. The following sections will outline what information is required to move from a
total carbon footprint to intensity metrics specific to transportation.

2.2 Reporting emissions per ton-kilometer or passenger-kilometer
The transport services and transport OEM sector questions in CDP’s climate change questionnairerequest companies to report primary intensity metrics. These metrics measure the efficiency oftransportation based on the actual work being done3. The amount of work done comprises thegoods and/or passengers moved and the distance, from origin to destination, that these goods
and/or passengers are moved. For the organization, the efficiency of total work done is determinedby combining total of transported units and the distance travelled with these units.
The work done is expressed as a common unit in tons of CO2e per unit of goods/passengers, perunit of distance. This is expressed as:

𝐸𝑚𝑖𝑠𝑠𝑖𝑜𝑛𝑠 𝑝𝑒𝑟 𝑢𝑛𝑖𝑡 𝑜𝑓 𝑤𝑜𝑟𝑘 𝑑𝑜𝑛𝑒 =∑ 𝑡𝐶𝑂2𝑒∑ 𝑡. 𝑘𝑚

In the rest of the document, for purposes of conciseness only the ton-kilometer (t.km) metric isused as an example, but tons can be substituted by passengers and kilometers by miles.
Numerator: ∑ tCO2e
In this metric, the numerator in tons of CO2e is equal to the total emissions from transportation
associated with the total ton-kilometers or passenger-kilometers that represent the work. This canbe calculated using standardized methods such as the World Resources Institute (WRI) GHG

3 Igor Davydenko et al., “Towards a Global CO2 Calculation Standard for Supply Chains: Suggestions forMethodological Improvements,” Transportation Research Part D: Transport and Environment 32 (October 1,2014): 362–72, https://doi.org/10.1016/j.trd.2014.08.023.

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Protocol 4, using fuel data, or can be estimated from standardized factors if the total work done isknown.

Denominator: ∑ t.km
Each element of the ton-kilometer metric is explained below, in line with the GLEC framework.
Ton“Mass, volume and density are common attributes of freight. Despite the pros and cons of each,weight is more widely used and was thus selected for use in the GLEC Framework; the mostcommon unit is the metric ton. In circumstances where the weight is not known, convention is wellestablished, or the operational characteristics dictate that an alternative unit for the amount ofgoods transported is required, then a conversion factor would be required to convert the amount ofgoods into a mass equivalent for the purposes of comparison. The basis for the weight to beincluded is the actual weight and not proxies such as ‘chargeable weight’; additionally, the weightshould include the product and packaging provided for transport by the shipper. Additional
packaging or handling equipment used by the carrier or LSP should not be included in the totalweight.”
Kilometer
The distance unit is the kilometer (which can be converted to or from miles as needed forapplication). Distance can be determined using the following approaches:
••

•

•

“Great circle distance (GCD), also known as direct distance “as the crow flies”
Shortest feasible distance (SFD), as produced by a route planning software package,
which may or may not take account of physical restrictions on a vehicle for example
weight and height restrictions
Planned distance: the shortest planned distance related to real operating conditions.
This is a modification of the theoretical SFD. For road, this takes into account weightand height restrictions and typical operational choices taken to avoid congestion
hotspots such as urban centers or local/small rural roads by using highways, unlessrequired for a collection or delivery
Actual distance travelled, e.g. based on knowledge of actual routings or odometerreadings

In general, the other approaches underestimate the distance travelled in comparison to the actual
distance. Therefore, a correction factor may be applied to the GCD, SFD or planned distances as
an approximation of actual distance travelled where it is not known. The correction factor should bemode-specific to reflect how direct the route network is. The appropriate approach for calculating
distance varies by mode […].
SFD, planned distance and actual distance are often used to estimate fuel used in the actual
transport of combined shipments, of routed trips.”
Figure 2 shows how this calculation is carried out to gather the emissions intensity, that covers alltransport movement made using aircraft. As a minimum, the questionnaire for transport OEMs
asks responders to calculate this as an average of all vehicles of a certain mode (LDV, HDV,Aircraft, Marine ships, Trains) produced and marketed by the company.
Reporting average figures across all vehicles of a certain mode may or may not be suitable to acompany's products or the vehicles that it uses, if those vehicles within a mode are very different
from each other. For example, for a trucking company that uses only heavy trucks that are of asimilar weight and size, the mode-average across all Heavy Duty Vehicles will be a strong metric.
4 World Resources Institute, “Greenhouse Gas Protocol: A Corporate Accounting and Reporting Standard,”

2017.
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However, for a company that operates both long-haul HDV trucks and small last mile delivery
trucks, the average will be very much influenced by the make-up of the fleet between these twotypes. Therefore, the organization is then encouraged to calculate and report separate figures: onefor long-haul heavy duty trucks, and one for smaller last mile delivery trucks. For aircraft operators,
a similar principle exists between intercontinental and national/regional flights, which are operated
on different types of aircraft with different efficiencies. In any case of a split between types,
organizations should ensure that the intensity calculation covers as much of the company'soperations as possible.

Figure 2: Calculating emissions intensity, example flowchart for aircraft operators transporting freight.

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3. Resources for calculating primary intensity metrics
3.1 Transport Services
For the purposes of reporting to CDP, transport service companies, are defined as companies
whose primary activity is the carrying of goods or passengers, or providing logistics services bysubcontracting transport movements, respectively named ‘carriers’ and ‘logistics service providers’(LSPs). In the CDP Corporate Questionnaire, companies are asked to calculate their primary
intensity per transport mode, in t.km or p.km, and supply the primary data points in useful work
done, as well as total transport-related GHG emissions (top panel in Figure 2).
How to use existing standards to calculate intensity metrics
It is expected that many organizations may not yet be familiar with reporting emissions per unit ofwork done. However, many standards, guidance documents and recommended practice alreadyuse this metric and have incorporated it in full.
The GLEC framework, as briefly explained in Box 1, is targeted at carriers, LSP’s, as well as
shippers (organizations who purchase transport services for their goods and/or passengers).
Furthermore, the framework is built on a large number of existing standards that your organization
may already use to calculate your transport emissions in Scope 1, 2 and 3. Figure 1 shows whichstandards are adopted and built on in the GLEC framework, and using one of these standards,
companies may use the GLEC framework to take the step from these standards to calculating youremissions intensity in tCO2e per t.km or p.km.
For example, for marine shipping companies, the Clean Cargo Working Group (CCWG) standard
for container shipping can be used to calculate an emissions intensity in tCO2e/20ft.km, or 20 footcontainer-kilometer. A standard conversion factor of 1 20ft container = 10 tons may be used toconvert this to an intensity in tCO2e/t.km. Please refer to the mode-specific guidance of the GLEC
framework for examples for LDV, HDV, Rail and Aviation as well. The following table lists thestandards that the framework is built on and links them to CDP’s transport services questionnaire,with a short overview of the steps necessary to gather the data and calculate the desired metric
per work done.
Table 1: Linking CDP transport modes to industry standards and methodologies

Transport modeStandard/methodology

Steps to get to metric per unitof work done

LDV/HDV (Light/Heavy dutyvehicle)

EN 16258

No major modification necessary

SmartWayNo major modification necessary

EcoTransIT

No major modification necessary

CCWG (Clean Cargo WorkingGroup)

Convert units to ton-kilometer(convert using standard weightfactor)

IMO Energy Efficiency
Operational Indicator (EEOI)No major modification necessary

IATA Recommended Practice1678 (RP 1678)

Already largely aligned, using
metrics per ton and passengerkilometer. Upscale CO2 to CO2e•

RailMarine (Sea)

Air

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3.2 Transport OEMs
Transport OEMs are asked to calculate an intensity metric as part of their Scope 3 emissions
breakdown. Many OEMs, especially auto manufacturers, are already calculating an intensity metricin the form of CO2 or CO2e per vehicle-kilometer. This metric however is not sufficient for reporting
to question 7.50, which asks for an intensity metric per unit of work done, as described in thisdocument.
Please note that this does not mean you are unable or discouraged to report emissions per vehicle
kilometer or mile, rather that this data belongs in a different question, namely 7.35. In this question,
you can select the appropriate numerator and denominator to report your data in 7.35. It is
expected that for the first year of reporting, OEMs may not be ready to report a Scope 3 emissions
intensity figure in passenger- or ton-kilometer for their entire fleet. In this case, you are encouraged
to start with the reporting of emissions per vehicle kilometer in 7.35, and then move to 7.50.
Ton- or passenger-kilometer vs. vehicle-kilometer
The difference between measuring CO2 or CO2e per vehicle-kilometer and the ton- or passengerkilometer metric that is desired is the load factor. This is a factor that converts the travel of one
vehicle to the total weight of goods in tons, or the number of passengers it carries. For example, forlight duty vehicles, the average load factor for passenger cars is between 1.2 and 1.7, dependingon the country 5. Transport OEMs may have to use assumptions such as this to gather an
expectation on how their vehicles will be utilized (the level of work that will be done with them).
It is important that this assumption is not equal to the maximum load factor but reflects someexpectation as to actual load factor. Service companies can also use assumptions and are likely tostart with those when not familiar with the t.km metric, however they are encouraged to try andgather primary data on the actual ton-kilometers that is independent of their vehicles, following theschematic in Figure 2.

5 EEA, “Occupancy Rates of Passenger Vehicles” (European Environment Agency, 2015).

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