Shock as retreat of Arctic sea ice releases deadly greenhouse gas

[kenfrequed]

16. Possibly

Though climate shifts of this magnitude usually spell extinction for massive numbers of species. It is currently thought that there is a big more gradiation in change of climate. Of course there is always the remote possibility of a permian level extinction as there are theories that excessive CO2 could eventaully lead to it.

Very large releases of Methane and other gasses via volcanism or massive die off could have raised the temperature of the earth such that the water would hold less dissolved gas which would have fed-back by killing more aquatic life forms, thereby releasing more methane during decomposition. There are of course other theories but several of them have some sort of methane/CO2 release as part of the puzzle and the fossil evidence supports this.