Aside from that, I took the first couple of sources I found googling as roughly accurate, and I see estimates of about 35B-45B tons total C02, where around 3B-3.5B might come from 8B humans breathing. So assuming those numbers are anything close to accurate, we are perhaps slightly less than 10%.
There is also the effect (the name of which I currently can't remember) that consumption increases when people think it does no harm. Like when LED lights were introduced, energy usage allegedly actually increased. Because people were using LED lights for all kinds of things that were NOT using incandescent lights before, as the energy used was thought to be negligible.
This is not true. More lights might be on, but the total energy usage for lights is currently falling with increased LED production. You can find lots of stated fears and speculation on the internet that it could happen - FUD - but not evidence. There is some indirect evidence not specific to LEDs that people sometimes do use more energy when the cost goes down. But LEDs are an order of magnitude more efficient than incandescents, and there has been no such 10x increase in lighting use. Per-capita electricity use in the US is currently falling slowly.