If something needs to be said then it must be said, but you have a higher likelihood of the other person receiving the message if you drop the aggressive tone. You're also investing in them listening to you in the future, as opposed to avoiding you because you have a tendency to shame them for being wrong on something.

And if someone "consistently has a negative impact on the environment" you can still confront them without being abrasive. They can still be fired without calling them stupid. Adding that kind of tone adds no information except that you lost your cool. You're making it sound like every instance that warrants confrontation is about an intentional and repeated offence.