Yes, I know it's not technically just methane, but methane is its primary constituent.
"Fossil gas" is also probably a suitable term, but I like "fossil methane" because it gets that spooky chemical name benefit.
Yeah I was mostly poking fun at idea that someone would see this and get the entirely opposite message OP intended:
Methane worse than CO2?
BURN ALL THE NATURAL GAS
....
Global warming solved!
I half expected to come back to a whole pile of downvotes lol