So you understand that the amount emitted over time is not equal to the amount currently present? Why, then, do you compare emissions when your question was about the amounts currently present?

>> So you understand that the amount emitted over time is not equal to the amount currently present?

I do, but you don't seem to since you came back with an attempt to quantify the "amount emitted over time"

my question was: >>> what percentage of CO2 in the atmosphere is attributed to human activity?

...and I even answered it myself :) ... it's ~4%

Your 4% number is also based on emission rates. My number and yours are both nonsense for the same reason. You can't make the attribution by looking at emissions alone.