Business travel was grounded during the pandemic. But it’s quickly taken off again. Making up 90% of business travel, flying is one of the most carbon intensive activities one can do. For those companies that need to fly, here’s how to measure scope 3 business travel flight emissions. 

Free guide: Measuring business travel emissions in line with the GHG Protocol

Why do companies need to measure business travel emissions?

Companies are reporting their emissions both voluntarily and mandatorily. 

Those companies caught in the EU Corporate Sustainability Reporting Directive (CSRD)’s net must report the emissions of their entire value chain, which includes the fiddly scope 3 emissions. There are 15 different categories of scope 3 emissions, one of which (category 6) is business travel.

What are business travel emissions?

The Greenhouse Gas (GHG) Protocol defines business travel emissions as emissions produced by the transportation of employees for business-related activities in vehicles owned or operated by third parties, such as aircraft, trains, buses, and passenger cars. Emissions resulting from staying in hotels can optionally be included as part of business travel emissions.

How to calculate business travel flight emissions

The GHG Protocol outlines three different methods for calculating business travel transport emissions: fuel-, distance-, and spend-based. Each method uses emission factors. The total emissions of each transport method is calculated then a proportionally distributed per passenger. 

Deciding which method to use depends on two factors: required granularity and data accessibility. Fuel-based calculations are the most accurate, while spend-based calculations are the most accessible. All three methods are accepted by the GHG protocol, and can therefore be used in CSRD reporting, and support decarbonisation.

Free guide: Measuring business travel emissions in line with the GHG Protocol

1. Spend-based method

The spend based method uses the amount spent and transport mode to estimate the amount of emissions produced. This is the most accessible method.

2. Distance-based method 

The distance-based method uses the distance and transport mode or vehicle type to estimate the amount of emissions produced. 

3. Fuel-based method 

The fuel-based method uses the amount of fuel consumed to estimate the amount of emissions produced. This is the most accurate method.

Once companies can report their business travel flight emissions, the next step is to manage them. For example, industry leaders are managing business travel emissions by setting a carbon budget. Like a financial budget, teams or employees get a set amount of emissions that can be “spent” on business travel each year. And to align with the company’s net zero goals, this budget reduces each year.

The GHG Protocol: Get your business travel emissions from your expense management platform

Calculating business travel emissions yourself is laborious, resource-intensive, and time-consuming. It requires your company to collect the necessary data inputs while updating and maintaining high quality emission factor databases. But you can fast-track this.

The GHG Protocol suggests companies collect business travel emissions data from their expense management platform. Have you asked if they can help?

How expense management platforms are supporting their customers by partnering with Lune

Expense management providers are differentiating from the competition by by embedding emissions reporting into their value proposition. By plugging Lune's API into their platform, they support their customers through climate compliance by transforming their spend data into audit-ready emissions data.

Case study: 200+ Payhawk clients adopt new emission reporting feature in 6 months

Business travel emissions can make-up a large proportion of a company’s carbon footprint. For those who deem travel essential, managing these emissions is essential.

To learn more about how to measure business travel emissions, including hotel stays, download Lune’s free guide: A quick guide to calculating business travel emissions