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How to Track Carbon Emissions by Shipping Mode

Reducing your carbon footprint can seem like a daunting task, but it doesn’t have to be. There are various sources of carbon emissions, and within the scope of transportation, under Scope 3 emissions, your carbon footprint can be broken down by shipping mode. Each mode of transportation brings its own set of challenges regarding reporting and tracking emissions, but the right tools and strategies can make it easier to navigate and achieve your CO2 reduction goals.

In this article, we’re discussing the main factors that affect how to track carbon emissions for each shipping mode: rail, road, air, and ocean, including considerations for your company to make more informed decisions toward sustainability.

The Basics of Tracking Carbon Emissions

Before we get into the individual considerations for each shipping mode, understand that two concepts about carbon emissions calculation are foundational across all modes. First, science tells us how much of each gas, including carbon dioxide, is produced by consuming a certain type of fuel. Tracking carbon emissions then is a matter of determining how much fuel is used. Unfortunately, this is no easy task. If the exact amount of fuel is unknown, it can be derived by measuring what is known or what can be calculated — like the engine’s fuel efficiency or the distance traveled — and plugging this into the calculation.

Second, we need a methodical approach to this data collection, along with a system for reporting. This brings reliability and consistency to ensure that we can detect even small changes — like when a shipper uses a slightly greener alternative freight route. All data must be accurate and precise. Without both accuracy and precision, there is a bigger margin of error from carbon emissions reporting that can hinder the ability to draw meaningful conclusions from the data.

How to Track Carbon Emissions for Fixed Routes: Rail and Inland Waterways

Rail and inland waterways are typically considered the greenest options for freight transport. Rail in particular is 3 to 4 times more fuel efficient than trucks, and it has an important role in reducing carbon emissions for longer-distance freight. The Association of American Railroads (AAR) estimates that if half of the truckloads traveling over 750 miles were instead transported by rail, this would lead to 26.2 million fewer tons of greenhouse gas emissions annually. 40% of long-distance freight volume currently travels via rail — yet it contributes only 1.9% of the total transport-related carbon emissions.

Inland waterways, like rivers, canals or other stretches of water used by barges, are responsible for a fraction of the carbon emissions compared to trains and trucks per ton—rail produces 40% more, while tanker trucks produce 800% more carbon emissions per ton. The Inland Rivers Ports and Terminals (IRPT) association estimates that one gallon of fuel can transport a tonne of cargo 514 miles by barge, while only 202 miles by rail and 59 miles by truck. Of course, inland waterway is not an option for all shipments, but when it is, and when used in combination with rail, it makes for low transportation carbon emissions.

Rail and inland waterways can simplify freight planning due to their fixed routes. Companies can easily calculate whether they can move a significant portion of their middle mile from truck to rail to decrease fuel consumption and CO2 emissions. The difficulty comes when companies try to calculate their carbon emissions without using a system specifically designed to be used for rail or inland waterways. Road distances may appear to be a good estimation that is close enough to these fixed distances; however, the discrepancy between an estimate using a road distance versus the actual rail or waterway distance shouldn’t be ignored.

It may not seem to produce a big difference in numbers, but using road distances is an opportunity for more problems. One estimation for a rail distance may have a small margin of error, but another might have a bigger difference, which breaks down the integrity of the reporting. Essentially, companies must be sure they have actual rail distances for their rail-related emissions, likewise for inland waterways, which they can get by using a geocoder to compute point-to-point distances. The rest of the carbon emission calculation requires additional data of the emissions according to the type of fuel used—or the generation of electricity–plus accurate distances.

How to Track Carbon Emissions for Road Transport

Within the transportation sector of GHG emissions, 57% are from light-duty vehicles, and 26% are from medium- and heavy-duty trucks. Clearly, a significant portion of these carbon emissions cannot be avoided by rerouting freight to another mode, but there is still a lot that can be done to reduce emissions in this area. For many companies, this is their most substantial source of emissions, so even incremental changes are significant in getting them closer to where they need to be.

Because trucks are unavoidable to an extent, reducing truck-related carbon emissions comes down to a few different approaches—using sources of energy that create fewer carbon emissions, using vehicles with increased fuel efficiency, or adopting practices that reduce waste, like reducing empty miles. Shippers not owning their own trucks do not have much influence over the first two, leaving the third as the area to focus on. Route optimization is one essential part of this. To thoroughly understand the different route options, it’s crucial to accurately calculate distances and fuel efficiency or fuel consumed, to calculate carbon emissions precisely.

Methods of calculation must take into account how the specifics of the truck, route, and freight affect the outcome rather than using general, default data. Distances can be calculated either as LOCODE or geocoordinates to ensure the best accuracy by pinpointing locations. For fuel, shippers must use factors like the type of truck, the region (including elevation information), and the type of goods transported to calculate accurate and precise numbers.

How to Track Carbon Emissions for Air Transport

When shippers choose between air and ocean for the first leg of transport, most of the time, the biggest factor is the speed of transit — a few days for air compared to a few weeks for ocean. Generally, higher speed is associated with increased carbon emissions, which is true of airfreight. Air accounts for only 8% of total carbon emissions in the transportation sector. Still, long-haul flights produce an estimated 47 times more emissions per ton per mile compared to ocean freight. A shipper might not use airfreight except when fast shipping is needed, but any changes they make from air to ocean are an opportunity to reduce their total CO2 emissions.

Tracking airfreight carbon emissions requires tracking distances and fuel. Like other modes of transport, air can use a geocoder to find exact airport locations and distances. However, calculating the amount of fuel can be complex, with added factors to include. Each flight phase (like taxi out, climb, cruise, descent, approach, landing, and taxi in) uses a different amount of fuel, which is different for each type of aircraft. There are also load factors for passengers and cargo based on whether the flight is long, medium, or short.The calculation should also consider the number of seats and the maximum payload of the aircraft for belly freight or freighters.

How to Track Carbon Emissions for Ocean Transport

While ocean freight per ton has a lower carbon footprint compared to airfreight, there is still work to be done for vessel owners to reduce emissions, especially since an estimated 80% of freight moves via ocean shipping. The International Maritime Organization (IMO) set the goal of a 40% reduction in carbon emissions by 2030 compared to 2008. To meet this requires upgrading vessels to increase their fuel efficiency, as old vessels are estimated to be five times less fuel efficient than new ones.

The exact vessel can be a significant factor in determining carbon emissions, which adds complexity since shippers do not know the exact vessel that will be used at the time of booking. Carbon emissions tracking for ocean freight should have two main objectives—to report on past emissions for a fleet and provide reliable data for the tendering phase before the specific vessel is known. In addition to the vessel and the engine it uses, ocean-related emissions also depend on speeds and distances. Because speed varies and routes change on an ongoing basis, it is essential to have vessel-specific data on the exact routes for each shipment.

How to Reduce CO2 Emissions for Any Mode of Transport

Reliable carbon emissions reporting for rail, road, air, and ocean depends on the methodology used for calculating emissions. To turn efforts into results, companies should use an established framework, like Searoutes uses—report, route, and reduce.

  • Report – The first step involves using the right methodology to find a shipper’s baseline numbers for carbon emissions data.. We recommend modeled data over primary or default data.
  • Route – Next, shippers must interpret the data to determine a plan for more optimal routing, leading to carbon emission reduction. This involves having data available on the alternative routing options.
  • Reduce – With reduced carbon emissions, proved by accurate and precise carbon accounting, these numbers can inform the next iteration of improvements toward CO2 emissions goals.

Use Searoutes Carbon Emissions Reporting for Rail, Road, Air, and Ocean Emissions

Shippers must have an approach to carbon emissions that covers rail, road, air, and ocean freight to understand their current baseline, their routing options, and to track their progress. Searoutes provides this data and calculation as an API-first solution for shippers to integrate, track their progress toward sustainability, and make more informed decisions. To learn more about tracking carbon emissions for any shipping mode, reach out to Searoutes today to book a demo.

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