[grues-dinner]

> not crazy or conspiratorial to look at these giant lines in the sky and think "those things must be doing something"

I think more accurately it's not crazy to think they might be doing something. I could equally be convinced if researchers crunched the numbers and concluded they might seem big but they're negligible on a global scale. In fact the same figure of "only 3%" of flights really have an effect" could easily have cut the other way.

A bit like how wind turbines look huge and numerous but are (as yet and for the foreseeable future) completely negligible on the scale of global wind power.

In fact plenty of times much closer to home, thinking "this very obvious thing must be having an effect" and failing to verify that it actually does has screwed me over repeatedly in everything from bug fixing to installing floorboards.

[burkaman]

Sure, I meant "must be" in the colloquial sense of "I have a suspicion", not "I am absolutely certain". Like "it's 5pm, must be a lot of traffic on the highway right now". If traffic turned out to be light I would be mildly surprised, update my assumptions and move on with my life.

[grues-dinner]

Fair enough, it was pedantic. But the distinction is exactly where conspiracists come unstuck.