[ROCKLOBSTER]

So how much is there, as a percentage?

Crickets chirping as you look it up, afraid to speak the truth...BUMP!

[dirtbiker]

Crickets chirping as you look it up, afraid to speak the truth.

At whatever level they state it is (I'll use 380 ppm), current levels as a percentage is about 0.04%.

As a reference, the atmosphere is about 78% nitrogen, 20% oxygen, 1% argon, and 1% of everything else, including CO2....

[palmer]

Crickets chirping as you look it up, afraid to speak the truth...BUMP!

I've posted it dozens if not hundreds of times.