0.04% = 0.0004 . just a different way of saying it.
so C02 is less than 0.0004 of the atmosphere.
C02 does not affect the Earth's climate
C02 has been skyrocketing but the Earth is getting colder and has been since 2000
the reason the left picked C02 is because capitalism/industry produce C02
Established science says CO2 absorbs energy in the atmosphere: http://scienceofdoom.com/2011/03/12/understanding-atmospheric-radiation-and-the-âgreenhouseâ-effect-â-part-nine/
C02 has been skyrocketing but the Earth is getting colder and has been since 2000
Not colder, but not significantly warmer either. Basically no effect, which means you are correct in the short run. In the long run you may be incorrect (see link above), or negative feedbacks, etc may mean you are correct again. Personally I think there is some effect in the long run, but weather and natural cycles will dominate.