DEFRA Conversion Factors

This article outlines the key emission factors used from the UK Department for Environment Food & Rural Affairs (DEFRA)

The UK DEFRA Conversion Factors are for use by UK and international organisations to report on greenhouse gas emissions. The factors are published annually and allow organisations to calculate greenhouse gas emissions from a wide range of activities. 

The 2020 Conversion Factors use Global Warming Potentials (GWP) factors from the Intergovernmental Panel on Climate Change (IPCC) fourth assessment report. The GWP for CH4 is 25 and the GWP for N2O is 298. The 2020 DEFRA Conversion Factors are available here.

Key factors used by Pathzero include:

Scope 1

  • Stationary combustion emission factors (kg CO2-e/GJ)
  • Mobile combustion emission factors (kg CO2-e/GJ)

Scope 2

  • UK electricity emission factor (kg CO2-e/kWh)

Scope 3

  • Electricity transmission and distribution loss emission factor (kg CO2-e/kWh)
  • Water treatment emission factor (kg CO2-e/million litres)
  • Waste disposal emission factors (kg CO2-e/tonnes)
  • Business air travel emission factors (kg CO2-e/passenger km)
  • Land travel emission factors (kg CO2-e/km)