So from my understanding, methane is produced solely in the decomposition of the matter, so yes it does bring down methane emissions. The second part about carbon is, from my understanding, just saying that, as plants do, remove carbon from the air and convert to oxygen.

But I was actually coming here to check about lomi composting. Since moving I've had some trouble keeping up with composting since my city does not deal with waste from large apartment complexes, so no curbside composting. I have plants too so this actually might be helpful if I can find it used…