“Essentially all” and “100%” are not the same thing from a scientific point of view and saying that “100% of global warming is due to human influence” just gives deniers a get out of jail free card.
Don’t be defensive about it — learn from the mistake and communicate better.
Scientists need to explain that they work with levels of confidence, not certainties, but that when a level of confidence is high enough, we can take something as a “practical” certainty. That language makes more sense to a layman — if some event is 99.99999999999999999 certain to occur, would you bet your hard earned cash against it?
Saying that something about the real world is certain just sounds like arrogance.
As the old saying goes, “If you want proof, don’t study Physics. Study high-school geometry.”