Taking one less work flight a year is probably better for the environment than almost anything else a person can do.

Judged against scientific evidence on per-person emissions as of Oct 2021; the hedge 'probably' and 'almost anything else' are part of the claim. True: lifecycle or carbon-footprint studies (e.g. Wynes & Nicholas 2017, IPCC, IEA) show that the emissions avoided by skipping one typical work flight a year are larger than those of nearly all common individual climate actions. Mostly true: one flight ranks among the top few individual actions, but a small number of common actions (e.g. going car-free, plant-based diet) clearly beat it. Mixed: one flight is middle-of-the-range, beating many common actions but beaten by several major ones. Mostly false: one flight (especially a short-haul one) saves noticeably less than several widely recommended major actions (living car-free, having fewer children, avoiding long-haul flights in general, switching to renewable energy, diet change), so the claim overstates a real but modest saving. False: the evidence shows one flight a year is a minor saving that many common actions clearly beat.

Set before the research began.

1. E1 The four lifestyle choices that most reduce your carbon footprint Lund University · 12 July 2017

   “The study found that, on average, eating a plant-based diet saves about 0.8 tonnes CO2-equivalents per year. Each roundtrip transatlantic flight avoided saves 1.6 tonnes, and living car-free for a year saves 2.4 tonnes.”

2. E2 The four lifestyle choices that most reduce your carbon footprint Lund University · 12 July 2017

   “But according to the study, eating a plant-based diet saves about 4 times more greenhouse gas emissions per year than recycling. Avoiding just one transatlantic flight saves 8 times more, and living car-free saves 11 times more.”

3. E3 The four lifestyle choices that most reduce your carbon footprint Lund University · 12 July 2017

   “Family size also mattered: when accounting for the impact of future descendants at current emission rates, having one fewer child would save 58.6 tonnes per year.”

4. E4 The four lifestyle choices that most reduce your carbon footprint Lund University · 12 July 2017

   “Note that long-haul flights are more (e.g., flying London to Hong Kong round trip is 2.97 tonnes).”

Lund University's summary of Wynes & Nicholas (2017) says avoiding one roundtrip transatlantic flight saves about 1.6 tonnes CO2e. That is more than a plant-based diet (0.8 t) and eight times more than recycling (E1, E2). Living car-free (2.4 t, E1) and having one fewer child (58.6 t, E3) clearly beat it, and long-haul flights save even more (E4). So skipping one flight ranks among the top few individual actions, but a small number of major actions save more. The evidence covers transatlantic flights, so it does not settle whether a shorter, more typical work flight would rank as high.