Methodology

How we calculate seafood transport emissions.

This page explains the logic behind our seafood transport emission calculator in a transparent and simplified way. We combine route distance, cargo weight, and freight emission factors from the GLEC framework to estimate total CO₂e emissions per shipment and per kilogram of product.

The detailed methodology is available in our report, while this page highlights the formulas and baseline values used in the app itself.

Paper Carbon App

How we calculate and estimate emissions:

1. Freight emissions model

For all transport modes:

\[ CO_2e = w \cdot d \cdot ef \]
  • \(CO_2e\): total emissions for a shipment (kg CO₂e)
  • \(w\): cargo weight (tonnes)
  • \(d\): route distance (km)
  • \(ef\): emission factor (kg CO₂e / tonne km)

2. Emissions per kg of product

To get the footprint per kilogram of seafood:

\[ CO_2e/kg = \frac{w \cdot d \cdot ef}{w_{kg}} \]
  • \(w_{kg}\): cargo weight in kilograms
  • Allows direct comparison across routes and transport modes

3. Total footprint across shipments

Summed over multiple shipments in a period:

\[ CO_{2e,\text{total}} = \sum_{i=1}^{n} w_i \cdot d_i \cdot ef_i \]
  • \(n\): number of shipments logged
  • Each shipment can have its own transport mode, fuel type, and route

The following emission factors are used in the calculator, sourced from the GLEC Framework (Smart Freight Centre) and Climatiq. All values are in kg CO₂e per tonne km.

4. Road Freight - Truck

Road freight is the most common mode for short and medium distance seafood distribution. Emissions vary significantly by fuel type (GLEC Framework, 2024):

  • Diesel: 0.096 kg CO₂e/tonne km
  • LNG: 0.080 kg CO₂e/tonne km
  • HVO (Biodiesel): 0.010 kg CO₂e/tonne km
  • Electric: 0.000 kg CO₂e/tonne km

5. Air Freight - Cargo Plane

Air freight is the most carbon intensive mode but is used for high value and time sensitive seafood exports. Emissions depend on fuel type (GLEC Framework, 2024):

  • Jet Fuel (Kerosene): 0.800 kg CO₂e/tonne km
  • SAF (Sustainable Aviation Fuel): 0.160 kg CO₂e/tonne km

6. Sea Freight - Cargo Ship

Sea freight is by far the lowest emission mode per tonne km, making it the preferred choice for long distance bulk seafood exports (Climatiq / GLEC Framework, 2024):

  • Diesel / HFO: 0.016 kg CO₂e/tonne km
  • LNG: 0.013 kg CO₂e/tonne km
  • Electric / Zero Emission: 0.000 kg CO₂e/tonne km