system
A chat on subreddit /r/wallstreetbets
human
I'm pretty sure that's what he thought it meant. There are 'clean'er forms of burning coal like carbon capture and storage (basically a tech for capturing some of the nasty stuff burning coal results in), but coal is still horrible for pretty much everyone and everything on Earth.

gpt
Coal is pretty good for the handful of people who still own coal mines and were too fucking stupid and arrogant to diversify at all.