As I write, world leaders and business gurus have been gathering in Glasgow since 31 October for the 26th UN Climate Change Conference of the Parties (COP26). Most of them got there by flying in on private jets. According to estimates from the Brussels-headquartered Transport and Environment campaign group, these jets ended up emitting 13,000 tonnes of CO2 into the atmosphere. To put this in context, the total carbon footprint of an ordinary Scot is around eight tonnes a year.

By the time they leave on 12 November, it seems unlikely, at present, that they will agree to UK Prime Minister Boris Johnson’s aim of committing to measures that will limit global warming to 1.5 degrees. Such an undertaking would go beyond the Paris agreements and effectively lock the world onto a 2050 net-zero target, based on current climate-change scientists’ projections.

Even if an agreement is reached, it will be done so without the presence of President Xi or President Putin, both of w