One of the considered hypotheses for the Permian-Triasic mass extinction event was the release of methane trapped in ice format (methane clathrates) - https://

One of the considered hypotheses for the Permian-Triasic mass extinction event was the release of methane trapped in ice format (methane clathrates) - https://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_event https://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extin... https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis#Possible_release_events https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis#Possi...