Your Air Travel CO₂ Emissions Could Be Off by 50%. Are You Confident in Your Data?
Following our recent webinar, “From Takeoff to Touchdown: Comparing CO₂ Calculation Methods for Business Air Travel,” we are also sharing the full report that compares three leading CO₂ calculation methods, highlights why emissions results can vary so dramatically, and what to consider when selecting a defensible, data-backed approach.
The Executive Summary is previewed below. For the full report and to watch the webinar, scroll to the end of this page.
Executive Summary
Measuring CO₂ emissions is a key aspect of business travel reporting. Air travel accounts for the largest share of these emissions and is particularly challenging to estimate accurately due to variations in flight routes and aircraft characteristics, such as fuel consumption and seating configuration. No single universal method exists for calculating emissions. In this study, we compared three commonly used approaches:
- Method 1, a Fuel-Time model which integrates fuel burn over flight time, considering the specific aircraft type and cabin class configuration. This is the main Areka method used to quantify air travel emissions and will be used as the standard of comparison [1]
- Method 2, a Fuel-Distance model which integrates fuel burn over the distance between origin and destination airports, considering the aircraft type and cabin class configuration.
- Method 3, a Pure-Distance model which applies cabin- and haul-dependent multipliers to the flight distance without explicit fuel modeling.
Using a sample of 316,200 flights, we find:
- Method 2 emissions are in good agreement (1%) with those calculated with Method 1
- Method 3 emissions are on average 13% higher than those calculated with Method 1
- Considering the travel patterns of ten representative organizations, larger deviations are observed; for example, the largest deviation between Method 3 and Method 1 was 47%.
- When considering the internal carbon price, the above deviation of 47% translates into a difference of $11 per ticket, and a carbon offset cost of $1 per ticket.
Comparing different components of business travel, we find that the air category accounts for over 80% of total emissions from trips booked through travel management companies. Examining emissions at the individual transaction level, the average values (rounded to the nearest ten), are:
- Air travel: 300 kg CO₂ per flight per passenger (computed using Method 1)
- Car rental: 120 kg CO₂ per rental period
- Hotel: 50 kg CO₂ per hotel stay
- Rail transportation: 10 kg CO₂ per segment
Finally, this study provides a detailed examination of the limitations inherent to distance-based methods, both qualitatively and quantitatively.
These findings not only underscore the relevance of fuel-based and time-based methodologies for carbon tracking in air travel but also advance the field by providing one of the first large-scale analyses comparing emission calculation methods across hundreds of thousands of flights.
Read the complete report here.
Watch the webinar recording below:
