carbon fart 

A person that is no longer in your life and basically dead to you, is a carbon fart.

David is nothing more than a carbon fart - nothing but hot air and empty promises. Can't believe he's one of my exes - what did I see in that guy?

carbon fart by Siouxsie Supertramp November 7, 2023

carbon fartprint 

That part of a person's carbon footprint caused by gaseous bodily emissions.

1. A moose has a carbon fartprint equivalent to a small car.

2. Despite their higher personal contribution vegetarians have a lower carbon fartprint than meat eaters as cows produce huge quantities of methane.

carbon fartprint by jamspoon September 18, 2007