One place where gas is flared off is landfills. Methane is produced by anaerobic decay and must be burned to reduce its climate impact.

One unfortunate consequence of this is bird injury, particularly raptors. They like to perch on the flare stack, and when it flares to life... if they are lucky, only their feathers are damaged and they can be rehabbed. This can probably be ameliorated by design of the stack to avoid perching, but that isn't always done.