Given present arrangements, the average additional annual carbon dioxide emissions arising from the use of additional capacity at Heathrow for the 60-year period 2020 to 2080 was set out in Annex B of the Adding Capacity at Heathrow Airport: Consultation Document, page 178. This was estimated at 3.0 million tonnes of carbon dioxide (MtCO2) per year.
This would mean that for the 30-year period 2020 to 2050, the average additional annual carbon dioxide emissions arising from the use of a third runway at Heathrow is 3.4 MtCO2, assuming no other changes.
The Government are, however, strongly committed to achieving reductions in carbon dioxide emissions and aims to do so in the most effective way. This is why we have led the debate within Europe to include all flights arriving at and departing from EU airports in the EU Emissions Trading Scheme from 2012 onwards.