The problem with comparing discussion of climate change to shouting "fire" in a burning theatre is one of immediacy.

Shouting "fire" to create a fake panic in a movie cinema is punishable, because it has been amply demonstrated through experience that creating a fake panic causes immediate, measurable harm; we know through observation of past events that people can be hurt or even killed during the resulting stampede.

But a public comment disputing alarmist climate claims; not so much.