Originally Posted by
cooker
There's a hypothetical possiblity the earth could have a methane burp of epoch-ending significance. I wonder what happened to all that end-Permian methane if that actually was a real event.
I don't know what happened to prehistoric methane, but modern methane turns into carbon dioxide within 10 years of being in the atmosphere. So my guess is that's what happened to the Permian stuff.
In today's world, methane exists in a form (called clathrate, IIRC) where it is frozen solid with water. This occurs in the tundra and on the floor of deep oceans. There is concern that it could melt as the climate warms and contribute even more to atmospheric warming.