The sensible thing to do would be to capture the methane and sell it.
Bingo!
You can go to many marshes, ponds and small lakes and do this. As plant matter decays methane is created from the decomposition process, its nature at work.
I don’t know that the volumes produced would be worth the cost of capturing it, but someone could look into the feasibility of it. Greenies would probably shut it down, as destroying the planet.