The UK Government tends to use the PHIA probability yardstick in most of its communications.
This is used very consistently in national security publications. It’s also commonly used by other UK Government departments as people frequently move between departments in the civil service, and documents often get reviewed for clearance by national security bodies before public release.
It is less granular than the IPCC terms at the extremes, but the ranges don’t overlap. I don’t know which is actually better to use in AI safety communications, but I think being clear if you are using either in your writing seems a good way to go! In any case being aware it’s a thing you’ll see in UK Government documents might be useful.
It should! Fixed, thank you :)