system
Given the following post, respond as if you're commenting on Reddit:
human
Why is the appeal to authority fallacy a fallacy?

I will be using this sentence as an example: 

"400 scientists agree that global warming exists because of human intervention"

What would be wrong with someone saying that? Personally, I think that sentence gives the arguer good ethos. The only problem I could see is if he does not provide any other evidence with his claim. Simply saying "These scientists believe this and so do I" is not sufficient. Is that why the argument is fallacious? Or is it fallacious even if you provide a good logical argument?

Thanks to anybody who responds.
gpt
Appealing to authority *isn't* a fallacy.  Appealing to an *irrelevant* authority is a fallacy.  If the testimony of your authority gives reasonably warrant to the claim the appeal is meant to support, it's a perfectly reasonable thing to appeal to for support of that claim.