Climate series, part 6

One Flight

Take one return flight from London to New York and draw it as a square. On its own it is huge — most of a sustainable year for everything you do. It looks tiny only because averages spread that seat across billions who never fly. So the real question is how often you could take it and stay within a fair share.

Sources and methods at the end.

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One ticket

The green block below is one London–New York return in economy class — a single seat, there and back. A short hop to Europe is about one-fifth as much.

The number includes the extra warming from flying high, not only the CO₂ from the fuel. Exact factors are listed at the end.

The seat is big

The whole green block is one return to New York — a single seat, there and back. The outlined box is a rough sustainable year for everything: heating, food, driving, goods, flying — about 2 tonnes. That one flight already fills about two-thirds of the whole year. (The 2-tonne mark is an editorial round number for this series, not an official ration.)

…so why does it feel small?

Because the numbers average it away. These hundred people stand for the world. Climate reports share flying's warming across all of them, so each equal share is a sliver — that is how you get lines like “aviation is only 2.5% of global CO₂.” Shared out evenly, one seat looks like a rounding error. But watch who is actually in this hundred.

The average was a trick

Almost none of them flew. In a recent year only about eleven in a hundred boarded a plane at all, and at most about one in a hundred — the most frequent fliers — likely cause more than half of all passenger-flying CO₂. The average smeared the seat across the ninety-nine bystanders who never left the ground. Put it where it truly falls and it snaps back, whole, onto the few.

So what would a fair share look like?

No amount of flying is simply “ok.” But there is a fairer question: what if everyone flew as often as you? Drag the dial. Once a year spends most of a whole sustainable budget on flying alone; stretch it toward once a decade and it shrinks to a corner of the box. That is a rhythm the planet could just about carry — but only if the seat were shared equally, which, as you just saw, it never is.

All climate posts

Sources

Every square on this page is computed at load from the figures above. Ticket factors include high-altitude effects; national aviation inventories often count gases without that uplift. Where those two meet, the captions say so.

In England, about half took no flight abroad last year, and the busiest sixth flew three or more times.