Isn't this a terrible idea in the large scale? By allowing animals to eat plastic, won't their metabolism release CO2 to the atmosphere through respiration? Pla

Isn't this a terrible idea in the large scale? By allowing animals to eat plastic, won't their metabolism release CO2 to the atmosphere through respiration? Plastic has lots of carbon. Isn't this the same as burning some plastic and saying 'plants can eat it now', just without the direct emissions? In the small scale, it can solve some local problems. But in the larger scale, shouldn't we just bury plastic deep underground? Of convert it to fuel in substitution of further fossil fuel extraction?