"efforts to dissuade people from air travel have been all but abandoned amid an absence of alternatives and a need to generate economic growth."

Airlines, airports and campaigners disagree profoundly on whether the best way to decarbonise aviation is through cleaner fuels, some form of carbon offsetting mechanism or reversing the growth in passenger numbers.

Most politicians take the view that more air travel results in more economic growth, bringing in tourism, creating jobs, and — hopefully — helping them get re-elected. London’s mayor, Sir Sadiq Khan, opposes Heathrow’s planned third runway but has welcomed expansion at other London airports. “I see the benefits of aviation to our city and our country in terms of jobs created, in terms of the economy, in terms of those of us that use planes to go on holiday and go on visits,” he says.

US opposition matters because some of the most polluting routes in the world, including the many London to New York services, are not covered by the EU, Switzerland or the UK’s carbon taxation schemes for flying.