Measurement & Analytics

Freight & Logistics Emissions Measurement - Factors and Methodologies

If you’re a freight or logistics company looking to take your first steps on the path to sustainability, you might find it difficult to know where to begin. Perhaps you have concerns about not having the right data, or you’re unsure about the regulations that you need to adhere to. In this blog post, we’ll give you a handy overview of the main methodologies used in the measurement of your carbon footprint, and how emissions factors work.

Primary data, default data or a modelled approach?

There are several different ways to calculate CO2 emissions depending on the information that you have at your disposal.

Primary data

The most accurate method is using primary data. Primary data comes in different forms — it can be the amount of petrol consumed in a particular journey, the exact distance travelled by a given shipment or the weight of a particular load of goods.

One of the most accurate methods of calculating CO2 emissions is fuel consumption. Here, you would use an emissions factor that would convert the kg of fuel used to kg of CO2. If you don’t have fuel consumption data for individual journeys, you can use average values from an aggregate of multiple journeys. This is still considered to be primary data, although it’s obviously less accurate than raw data for each separate journey.

The major benefit of primary data is accuracy, but the downside is the fact that it isn’t widely available, particularly for air transport and shipping. For road transport, telematics allow for accurate readings of the fuel consumed in given truck journeys. For shipping however, companies rely on data from individual suppliers, who may not share this information with partners. The same is true for individual airlines.

Default data — emissions factors

Given the difficult access to primary data, there are default values that can be used for measurement. These factors are typically built bottom-up from historical primary data. For example, the GLEC framework factors are most widely-used in Freight and Logistics, but there are others which are more specific to given areas. EPA Smartway factors are commonly used for US-related emissions, DBEIS (formerly DEFRA) for UK emissions and ADEME for France.

Detailed modelling

Detailed modelling can be viewed as the middle ground between primary data and default data. It’s a method of gaining a greater level of accuracy even if you don’t have access to all the primary data. Usually, it entails using additional details that you have about the mode of transport being used. Two such additional details are IMO numbers and aircraft codes.

IMO numbers for ships

The International Maritime Organization number (IMO), a unique identifier for ships, is useful for emissions calculations, particularly when it comes to filling in missing data. The number enables you to retrieve any data about a given ship, including its type and weight — which are important factors for accurately calculating emissions.

Airline and aircraft codes

For Air freight, airline and aircraft codes can be used to accurately identify an aircraft model and its corresponding layout. Having access to these plane specific details is important as it impacts how the aircraft load factor and fuel consumption is derived. This allows you to use calculation methodologies that go beyond the GHG protocol baseline and don’t rely on average emission intensity factors. In addition, flight numbers can be used to retrieve the actual distance flown by the aircraft, to give a more accurate output.

Calculating the footprint of specific transportation journeys

The basic method of calculating the footprint of a specific journey is to use the previously mentioned emissions intensity factors, and combine them with several other important data points, which vary by methodology.

The Greenhouse Gas (GHG) Protocol is one of the most commonly known approaches. It recommends combining the distance travelled, the weight carried (when relevant) and the emissions intensity factor for the corresponding vehicle, fuel type and geography.

Domain specific methodologies are also available. For air transport, the International Civil Aviation Organization (ICAO) developed an emissions calculation approach which is well recognised.

While there are multiple ways to calculate carbon footprint, not all these methodologies are robust and can be trusted. Being able to verify the source of the calculation conducted by your climate partner is essential. The best way to do this is by checking whether the methodology is accredited by a recognised body such as GLEC.

The GLEC framework

Established by The Smart Freight Centre (SFC), a nonprofit organisation dedicated to sustainable freight, GLEC is the only globally recognised methodology for calculating and reporting on the greenhouse gas footprint across the logistics supply chain.

In 2016, the SFC released the GLEC Framework, in alignment with the Greenhouse Gas Protocol, UN-led Global Green Freight Action Plan, ICAO, Smartways, Clean Cargo and CDP reporting. This acts as a guide for companies on how to measure and report on their transport emissions.

A new ISO standard which builds on the GLEC framework is due to be published at the end of 2022. This will cover both passenger and freight transport.

CO2 and CO2e Emissions

You may have seen CO2e used in emissions calculations and wondered how it differs from CO2. CO2e stands for ‘Carbon Dioxide Equivalent’ which includes CO2 and other greenhouse gases, including nitrous oxide (N2O) and methane (CH4). It is used to measure the 100-year global warming potential (GWP) of these greenhouse gases. This measure, expressed as GWP, differs for different types of gases.

For example, CO2 has a GWP of 1 while methane has a GWP of approximately 25. This therefore means that 1g of CH4 in CO2e is equal to 25gCO2e.

It’s useful to express carbon footprint in terms of CO2e, because it means you can know for sure that all greenhouse gases have been included for each activity in scope, and therefore you can get a fuller picture of your emissions.

Things to consider when selecting your methodology

If you’re just starting your journey of computing your CO2e, begin by checking what data you have access to. Then make the decision on how to calculate your emissions. You may choose to use an in house team to conduct your measurements, to use an external consultancy or a tech partner. For a full list of the types of questions that you should be asking your climate tech provider, take a look here.