[rey]

Where do you get that man is responsible for 3.4% of the .04% carbon in the atmosphere? I would love to have a source on that.

[palmer]

3.5% (very rough estimate) comes from comparing manmade CO2 (about 30 Gt) to naturally created CO2 (about 800-900 Gt) on an annual basis. But the important part that is left out is that the natural flux is bidirectional. A large portion of the 800-900 Gt is produced in the fall and winter from decaying vegetation in the northern hemisphere and warmer water in the southern hemisphere outgassing (their spring and summer).

But in the spring and summer the deciduous vegetation in the northern hemisphere soaks it all back up. Meanwhile the ocean constantly absorbing on a net basis. The seasonal nature of the natural flux is apparent here:

[Bob434]

[[Where do you get that man is responsible for 3.4% of the .04% carbon in the atmosphere?]]

I can’t remember now, but here’s some info I found quickly

“Anthropogenic (man-made) CO2 additions comprise (11,880 / 370,484) or 3.207% of all greenhouse gas concentrations, (ignoring water vapor).”

http://www.geocraft.com/WVFossils/greenhouse_data.html

Note, this site lists ALL of the greenhouse gases, which figure out differently, but is still only 0.117% produced by man- if we are talking just CO2 produced by man, the figure comes out to just 0.00137& of the atmosphere