This article says Big Energy corps drill methane wells and then cheat the cost of plugging them by selling them to smaller companies that can't afford the plugging cost, thereby abandoning these wells to leak the potent greenhouse gas methane. I just tried to research how much methane is leaked and found this EPA report saying unplugged wells leak an average of 10.02 grams/hour of methane compared to 0.002 grams/hour for plugged:

https://www.epa.gov/sites/default/files/2018-04/documents/gh...

But 10.02 grams doesn't seem like very much, considering livestock methane emissions (like cow farts and burps) were estimated in 2011 to produce 120 trillion grams of methane per year:

https://www.forbes.com/sites/samlemonick/2017/09/29/scientis...

So it certainly is a Big Energy sin, but there are graver stakes (involving gravy and steaks).