CARBON dioxide emissions from aircraft contribute to two per cent of the global total. For the UK it is actually more like 13 per cent.

That is because official figures assume half of the passengers on a flight are from the destination and half from the originating countries, but for UK flights the proportion of Brits on board in both directions is much higher.

Air travel is actually worse than this because it puts out more than just CO2. Nitrous oxide is another greenhouse gas also released by jet engines.

It is infamous as a pollutant released by diesel cars, but it is is a strong greenhouse gas at high altitudes – which is exactly where the jet engines go. It is for this reason that the Green Party campaigns against expanding airport capacity like the third runway at Heathrow.

READ MORE: Why 20's plenty

Your average Brit takes a short-haul holiday return flight every two years (say five hours in total, to the Algarve and back – that's two hours per year) and a long haul flight every five years (22 hours return to Hong Kong – that’s four hours per year).

That’s about half a tonne a year (or nearly a month's worth of emissions from all your activities, cooking, driving, heating your house). A fairly painless way to make a big cut in your CO2 in a given year is to not fly in it.

You may have noticed that if you multiply all this up across the country you don't come near the 13 per cent mentioned earlier.

Recent reports show that the vast majority of flights are made by a very few people.

A frequent flyer levy is gaining momentum, where the majority of people would pay nothing, but only the frequent flyers pay a levy that increases each time they fly per year.