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Definition

Aviation radiative-forcing uplift

Aviation radiative-forcing uplift increases a flight emissions estimate to represent non-CO2 warming effects at altitude, such as contrails and changes caused by nitrogen oxides and water vapour.

What is aviation radiative-forcing uplift?

The uplift adds an estimate for aviation's non-CO2 climate effects to direct flight emissions. UK DESNZ's 2026 methodology, paragraphs 8.39 to 8.43, recommends a central multiplier of 1.7 on the CO2 component only. DESNZ warns that this value is uncertain and does not turn the non-CO2 effects into a precise carbon dioxide equivalent (CO2e).

Why does aviation radiative-forcing uplift matter to you?

GHG Protocol Category 6 says you may apply a correction for radiative forcing to air-travel factors and must disclose the specific factor used. A customer cannot make a reliable like-for-like comparison with another year or supplier calculation unless you state whether your factor includes the radiative-forcing (RF) uplift.

How is aviation radiative-forcing uplift calculated?

Use a published factor already labelled "with RF" from the public factor ledger. Passenger-km is the flight distance multiplied by the number of passengers. Multiply that total by the factor in kg CO2e/passenger.km. DESNZ publishes separate with-RF tables. Its 1.7 multiplier applies only to CO2, not again to methane or nitrous oxide. The separate 8% great-circle distance uplift covers indirect flight paths and delays, not non-CO2 warming.

What mistakes should you avoid?

  • Multiplying a with-RF factor by 1.7 again.
  • Treating the 8% distance correction as the RF uplift.
  • Mixing with-RF and without-RF factors across reporting years without explaining the change.

Is aviation radiative-forcing uplift mandatory?

No. GHG Protocol Category 6 says it may be applied. Follow the method named in your request, and keep the choice consistent with your base year.

What should you record when you use the uplift?

Keep the factor key, value, unit, source, publication year, flight class, distance method, reporting period, and a clear "with RF" label.

Example

Suppose a dairy processor in Vietnam records two employees who each flew 20,000 km on long-haul return trips in 2026. Two passengers x 20,000 km gives 40,000 passenger-km. Cabin class is unknown. It uses factor key flight_long_haul_average_with_rf_desnz_2026: 0.15282 kg CO2e/passenger.km, geography Global, publication year 2026, from UK DESNZ and DEFRA's UK Government GHG Conversion Factors for Company Reporting 2026.

Calculation: 40,000 passenger-km x 0.15282 kg CO2e/passenger.km = 6,112.8 kg CO2e, or 6.11 metric tonnes CO2e rounded to two decimals. The processor does not apply 1.7 again because the factor already includes RF. It records the UK-source factor as a proxy for Vietnam-linked travel.

Where it comes up

GHG Protocol Category 6 disclosure of a radiative-forcing correction used for air travelScope 3 Calculation Guidance, Category 6, distance-based method note, page 83Official sourceUK Government 2026 separate business-travel flight factors including radiative forcingDESNZ 2026 conversion-factor methodology, paragraphs 8.39-8.44

Related terms

Scope 3 Category 6: Business travel

Scope 3 Category 6 covers emissions from employee business travel in aircraft, trains, buses, rental or employee-owned cars, and other vehicles your company does not own or control.

Emission factor

An emission factor converts a measured activity, such as kilowatt-hours of electricity or litres of fuel, into greenhouse gas emissions by stating the emissions released per unit of that activity.

Global warming potential (GWP)

Global warming potential (GWP) is the multiplier that converts the mass of methane, nitrous oxide, refrigerants and other non-CO2 greenhouse gases into carbon dioxide equivalent over a stated time horizon.

CO2 equivalent (CO2e)

CO2 equivalent (CO2e) expresses different greenhouse gases in one unit by multiplying each gas's mass by its specified 100-year global warming potential, then adding the converted amounts.

Sources

  • UK Department for Energy Security and Net Zero

    Paragraphs 8.36-8.44 on the 8% distance uplift, non-CO2 effects, the 1.7 multiplier, uncertainty, application to CO2 only, and separate with-RF factors

    2026-08-20

  • GHG Protocol

    Category 6 distance-based method, passenger-km formula, optional radiative-forcing correction, and disclosure of the factor used

    2026-08-20

Last verified 2026-08-20

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Aviation radiative-forcing uplift Definition | Keslio