One small plus for coal is that it doesn't leak. With better satellite observation now, we're finding out how underreported the emissions of methane from natural gas extraction were.
Due to thermal insulation and the avoidance of rain/snow extinguishment by the crust, underground coal-seam fires are the most persistent fires on Earth and can burn for thousands of years, like Burning Mountain in Australia.
https://www.osmre.gov/programs/mine-fires
~ https://en.wikipedia.org/wiki/Coal-seam_fire