On the surface, calculating emissions from transport is a simple process—so simple, in fact, that it can be broken down into a three-part formula. The reality is that once you get deeper into the topic, it becomes clear that measuring transport emissions is more complex.
You will find yourself asking questions like: what data should I use? What is the most appropriate methodology? Which emission factor is most relevant?
These are questions many companies will soon have to face. Along with stakeholder demand for increased emissions transparency, pressure is also mounting from regulators—take the Corporate Sustainability Reporting Directive (CSRD), for example, which stipulates reporting emissions from scope 3 activities including freight and logistics operations.
The gold standard for freight emissions measurements are fuel-based calculations. They produce the most accurate results as the activity is closest to the source of emissions (burning fuel, which releases CO2, N2O, and CH4).
Fuel consumption data, however, is often unavailable, hidden in third-party logistics (3PL) providers’ systems. For others, fuel data is often scattered between Transport Management Systems (TMS) and Enterprise Resource Planning (ERP) platforms, leading to data silos. In such cases, fuel use must be estimated. This can be done using emission factors that include fuel estimates, like distance or weight-over-distance emission factors, which act as substitutes for actual fuel data.
Once you have the fuel data—actual or estimated—it must be allocated to specific shipments. This usually involves data on cargo weight and distance travelled.
It’s also essential to account for fuel used in empty runs and distribute it appropriately across all shipments. Some emission factors, like those provided by GLEC, already include default allocations for empty runs, meaning it doesn’t have to be calculated separately.
The process of calculating freight emissions begins with collecting the necessary shipment data. Everything else, such as the calculation methodology and necessary emission factors, depends on what data is available to you. For example, fuel-based calculations require—as a minimum—the amount and type of fuel used; the weight-over-distance method requires weight, distance traveled, and mode of transport (sea, air, rail, road).
Note that the accuracy of the emission estimates will likely increase with the granularity of data provided.
Below is a list of common information needed to perform freight emissions calculations, depending on the method used.
The Greenhouse Gas Protocol (GHGP) establishes a framework to guide corporate standards for carbon accounting and reporting based on five principles, which can be useful to keep in mind when sourcing data for emissions calculations.
Many companies rely on 3PL providers to ship their products. These third-party firms manage a range of logistics functions using complex data systems, which can make accessing the relevant transport and shipment information challenging.
If 3PL providers are involved in the logistics network, it’s helpful to ask these service providers specific questions to gather the necessary data, such as:
Which methodology to use for estimating emissions depends on the available shipment data. While fuel-based methods are preferred for accuracy, the required fuel consumption data is often unavailable so alternative methods are necessary to fill the gaps.
For companies tracking logistics across multiple transport modes, it's best to choose a methodology that works across vehicle types, enabling comparisons between modes. Maritime shipping companies, on the other hand, might opt for a shipping-specific methodology. While this can be sufficient, it’s important to consider how this data aligns with the requirements of industry reporting standards.
The choice of methodology should not only meet your current needs but also support your future requirements. Auditors typically prefer consistency in calculation methodologies over time, as different methods can produce varying results. Maintaining the same approach improves comparability and allows you to more reliably track progress over time.
Accounting and reporting frameworks provide direction on how to perform emissions calculations in order to meet reporting requirements and measure progress. Calculating emissions following an approved framework increases credibility, provides estimates that are suitable for reporting processes, and increases their usefulness in comparing freight options. Here are the three most common frameworks for freight emissions calculations.
GLEC Framework: The Global Logistics Emissions Council (GLEC) Framework is widely adopted across logistics, covering transport and hub emissions anywhere in the world, making it the most suitable choice for most companies. It provides a way to implement the ISO14083 standard (see below) which was based on the GLEC Framework.
ISO 14083: This new ISO standard is set to become the global industry standard for measuring and reporting GHG emissions from both freight and passenger transport. Emissions intensities are specified for vehicles and hubs, allowing them to be used as reference points for calculating emissions.
GHG Protocol (GHGP): The GHGP accounts for emissions from freight in scope 3, categories 4 (upstream) and 9 (downstream) transportation. It outlines three methods for measuring emissions from freight transportation: the fuel-based method, the distance-based method, and the spend-based method in the case that other data is not available.
In the final step, the freight data collected needs to be turned into emissions estimates using relevant emission factors. These emission factors may be (dependent on the chosen methodology):
Some associations supply their own emission factors. The GLEC Framework, for example, provides a set of emission factors which can be used for GLEC-compliant calculations. Governing bodies are often a good source for reliable factors: the IPCC provides a database of emission factors; the UK Government database is especially well regarded and widely used; the GHG Protocol website also supplies emission factors. Climatiq aggregates and harmonizes factors from all of these sources and many more to cover a range of calculation methodologies, input types, and units. Transportation carriers may potentially issue their own emission factors, though it’s important to verify these align with the chosen methodology.
Transport emission factors should, where possible, include well-to-tank (WTT) emissions. WTT is a lifecycle assessment (LCA) phase that accounts for all greenhouse gas emissions from the production, transportation, transformation, and distribution of the fuel used to power the vehicle. Emission factors in the Climatiq database are all annotated with associated metadata indicating LCA activity, making it easy to determine what stage(s) each factor covers.
Each step of the emissions calculation process presents challenges. Data collection is time-consuming and often obstructed by 3PL providers or data silos, where information is isolated within departments. Just finding the right emission factors among thousands of options, each tailored to specific variables such as transport modes, vehicle types, and regions, is a major task requiring in-depth expertise. Adding to this complexity are the varying requirements of reporting frameworks, each with its own methodology and compliance standards. Understanding the requirements while ensuring accuracy can be daunting, particularly for businesses scaling their emissions tracking capabilities.
To address these challenges, automated solutions such as carbon calculators, APIs, and business intelligence tools are transforming how freight emissions are calculated, made transparent, and used to provide actionable insights. These tools leverage comprehensive datasets and advanced algorithms to automatically map transport activities to the correct emission factors, streamlining shipping route and distance calculations and reducing human error. They also allow users to adjust variables such as transport modes and vehicle types with ease, enabling precise estimates, scenario planning, and exploration of what-if scenarios to support better decision-making, even in the case that primary data is not available. By automating these processes, businesses save significant time and resources while eliminating the errors and compliance risk linked to manual calculations.
To explore how APIs can simplify the task of calculating compliant freight emissions, check out Climatiq’s Intermodal Freight Emissions feature.
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