Since personal flights account for 8 per cent of the UK’s carbon equivalent emissions (12 per cent if you add in business travel and airfreight), there is no way round this – we have to reduce the amount we fly.

There is no realistic way to offset the amount of CO2e that is generated by a flight. Worse still, airplanes emit their CO2 at altitude which aggravates the effect of the emissions.

If you fly business class, you will be responsible for about 3 times the emissions of someone in economy. If you fly first class, it would be four times.

Each flight generates tonnes of CO2 equivalent per person. (When we look at food, we are talking about kilos of CO2e – one thousand times less).

If we take the accepted view that people in wealthy countries need to reduce their carbon footprint to about 5 tonnes CO2e per year, one long haul flight in economy would use up about 70% – leaving nothing realistic for food, clothing, housing, etc.

Can we fall in love again with travelling the old-fashioned way on ferries and trains? What flights can we replace?