Clathrate:
And most of the methane that we do have is produced by biology. Things die and their hydrocarbons get trapped in stores deep underground or in permafrost, where it’s known as a clathrate. [“Curiosity Rover Finds Organics Hidden In Mars’ Mudstones And Methane In Its Atmosphere,” Eric Betz, D-brief]
Clathrates are of some concern to climate scientists as methane, while it doesn’t survive long in our atmosphere, is a more highly potent climate change component than CO2. Clathrates are known to exist buried in sediment of the ocean floor of the colder oceans.
