What would actually get you to cut back on flying — a carbon tax, or shame from friends who stopped posting airport gate photos? I know a handful of people who gave up two or three short-haul flights a year and then quietly flew to Bali, so the line between sacrifice and performance feels blurry. A return London–Barcelona flight emits roughly 0.5 tonnes of CO2 per passenger, about what an average car produces in three months, so the numbers aren't trivial. But I've also seen studies suggesting that where you live and how you heat your home matter more than one holiday. Does personal flight shaming work, or does it just push the problem onto people who care enough to feel guilty?