Being blunt depends on authority, which, when ineffectual, requires force. I would be more persuasive, which requires some kind of art.
OK.
78% = Nitrogen (is that a "greenhouse gas"?)
21% = Oxygen (is that a "greenhouse gas"?)
.9% = Argon
99.9% is the total so far
Is the rest of that 0.1% (1/10th of a percent) CO2?