Is atheism a scientific perspective?

[Anomalocaris]

I think what people would call hard atheism is unscientific.
People who claim to know there is no God which is basically claiming knowledge about something that isn't testable.
In general practical terms though most atheists just reject religion. And since the mainstream religions make unscientific claims then the absence of belief in those claims could give someone a scientific advantage.

Would you call people who say there is not a big bowl of spaghetti levitating 5000 Kms  over the North Pole of Jupiter "unscientific"?

Science is about making probability weighted statements.  If the probability of a statement being true, based on what is know, can judged overwhelming, it is waste of breadth to hedge. Any intelligent person, when hearing an unhedged statement about an overwhelming probability, knows the subtlety. Only religious idiots invested in the overwhelmingly improbable somehow being acknowledged as true, would quibble. Just because religious morons take offense at that statement that their god's chance of existing is on par with a bowl of spehatti floating 5000 Kms over Jupiter does not make it less scientific to say "the god of christians does not exist" then to say "the said levitating bowl of spaghetti does not exist"