Judging from the headline (I'm not going to read PETA), this is about the issues pertaining to the wellbeing of chickens, not the other externalities I actually mentioned.

Land use for animal agriculture has shrunk over time in the US. Methane is highest for cows, not that high with chickens. With the right practices (admittedly, they aren't migrating the clocks to fertilize land) this could be carbon-neutral, but notwithstanding, methane does not persist in the atmosphere nearly as long as CO2 does.

You lost all credibility by linking to PETA imo

PETA is full of shit, to the point where you could probably safely take on the opposite of their position on any given issue and presume to be correct, generally.