To ask the Secretary of State for Transport what level of radiative multiplier was incorporated in the calculations of the carbon emissions data shown in the Adding Capacity at Heathrow airport public consultation document; and if he will make a statement. (241995)

The Adding Capacity at Heathrow Airport consultation document, page 138, explains that the relevant assumptions are set out in the UK Air Passenger Demand and CO₂ Forecasts report, available at:

http://www.dft.gov.uk/pgr/aviation/environmentalissues/ukairdemandandco2forecasts/

The radiative forcing factor is set out on page 74 of that report. This factor is used by the Department for Transport to uplift the value of climate change impacts to account for the warming effects of non-carbon dioxide emissions released at altitude, and is equal to 1.9.