> 80% CO2 doesn't seem very high Are you a visitor from Venus? :) https://en.wikipedia.org/wiki/Atmosphere_of_Venus https://en.wikipedia.org/wiki/Atmosphere_of

> 80% CO2 doesn't seem very high Are you a visitor from Venus? :) https://en.wikipedia.org/wiki/Atmosphere_of_Venus https://en.wikipedia.org/wiki/Atmosphere_of_Venus Joke aside, as other posters say the CO2 concentration is more like 0.04% and even an increase for that is considered a contributing factor in global warming.