Navigating the Hidden Carbon Costs of Travel: The Importance of Well-to-Tank Emissions

We’re decoding well-to-tank emissions in the transport sector industry and its impact on your carbon footprint.

Written by Cameron Kelly on 27 February, 2024

In the realm of sustainable travel, the conversation is evolving beyond the visible trails of carbon emissions left by airplanes in the sky. The spotlight is increasingly on the less visible, but equally significant, well-to-tank (WTT) emissions. These emissions, emanating from the extraction, refinement, and transportation of fuel before it even reaches the vehicle's tank, account for as much as 20% of the travel industry's carbon footprint. At Thrust Carbon, we've unveiled these hidden emissions, providing businesses with the tools needed to make informed, sustainable travel decisions. This post explores the significance of WTT emissions and introduces Thrust Carbon's groundbreaking approach to incorporating travel’s overlooked emissions into carbon accounting.

What are Well-to-Tank Emissions?

Well-to-tank emissions account for the environmental impact from fuel extraction to its refinement and delivery into vehicles, adding a crucial layer to travel’s carbon footprint. Notably, in aviation, WTT emissions can form up to 20% of a flight's total emissions, underscoring their significance in thorough carbon accounting.

Before we go any further, here are some quick definitions:

  • Well-to-tank: This covers everything needed to get fuel ready and into the vehicle, from getting oil out of the ground, making it into jet fuel, and then getting it into the vehicle’s fuel tanks.
  • Tank-to-wake: This is all about what happens with the fuel once it's in the vehicle, from storing it in the vehicle, to turning it into the energy that powers the engines, and finally using that energy for propulsion.


This is best displayed in the image below, which also shows ‘Well-to-Wake’ which is the emissions from the entire upstream and downstream of the fuel.

Exploring WTT Emissions Calculation Methodologies

Now that we understand the importance of well-to-tank (WTT) emissions, it's essential to understand how these are quantified. Thrust Carbon distinguishes itself by adopting a dual-methodology approach, marrying the traditional DEFRA standards with our groundbreaking use of Nature Communications data. This fusion is designed to cater to diverse needs within the sustainability landscape, ensuring precision and compliance in reporting.

Methodologies at a Glance:

  • DEFRA's Approach: A cornerstone in the industry, DEFRA's methodology is based on a comprehensive 2015 study, focusing on fuels used in EU refining up to 2012. It remains a reliable choice for clients seeking a well-established benchmark across all vehicle types.
  • Nature Communications for ICAO+: Thrust Carbon elevates WTT emissions reporting with an innovative dataset from Nature Communications, enriching our ICAO+ air methodology. This data from 2017 covers around 80 countries, offering an unprecedented level of detail that accurately reflects the global fuel supply chain's complexities.

The unparalleled detail provided by the Nature Communications dataset is essential for a nuanced understanding of global fuel supply chains. Such granularity is invaluable, considering the significant variance in upstream emissions based on a country's fuel production versus import dynamics, as well as the geographical source of these imports. This variance underscores the importance of a tailored approach to calculating well-to-tank emissions, ensuring that our clients receive data that accurately reflect the real-world complexities of fuel supply chains. You can see this in the image below:

(Jing, Liang et al. “Understanding variability in petroleum jet fuel life cycle greenhouse gas emissions to inform aviation decarbonization.” Nature communications vol. 13,1 7853. 21 Dec. 2022, doi:10.1038/s41467-022-35392-1)

Rationale for Our Dual-Methodology Strategy

Our commitment to offering both methodologies is driven by a desire to provide flexibility, meeting our clients' varying requirements. While DEFRA offers familiarity and broad acceptance, Nature Communications brings a new dimension of accuracy and global relevance. This approach underscores our dedication to enhancing carbon accounting practices, ensuring clients benefit from the most comprehensive and current data.

Thrust Carbon’s Innovations in Emissions Calculations

Our recent enhancements to the Thrust Calculator and API signify more than an update—they represent a leap in how carbon reporting is conducted. By incorporating WTT emissions across all vehicle types and enriching our ICAO+ methodology with Nature Communications' precise, country-level data, we're redefining standards in environmental impact assessment. These innovations not only improve carbon reporting quality but also empower businesses with the insights needed for more sustainable travel management.

Empowering Sustainable Travel Decisions

Understanding WTT emissions is more than a technical exercise; it's a crucial step toward more responsible travel management. With our enhanced tools, companies can:

  • Comply with Emerging Standards: Stay ahead of the curve in meeting SBTi and other reporting requirements, anticipating the inclusion of WTT emissions in future regulations.
  • Make Informed Choices: Evaluate the environmental impact of travel routes and modes with greater precision, considering the variance in WTT emissions by country and region.
  • Customize Reporting: Adjust emission calculations based on the latest, most relevant data, ensuring that sustainability efforts are as effective and informed as possible.


A Greener Path Forward

The journey toward sustainable business travel is complex, but it's made easier with the right tools and insights. By embracing well-to-tank emissions in our carbon accounting practices, we can uncover the full scope of our environmental impact and take meaningful steps to reduce it. Thrust Carbon is here to guide you through this journey, providing the data, tools, and expertise needed to chart a greener path forward in business travel.

To learn more about how well-to-tank emissions can inform your travel decisions and to explore Thrust Carbon's suite of carbon management tools, book a demo or contact your customer success manager today. 

Together, we can transform the way the world travels, making every journey a step toward a more sustainable future.


Footer Background