It's more like microbes eat stuff -> greenhouse gases released -> climate warms -> more permafrost melts -> microbes eat more stuff -> feedback loop which event

It's more like microbes eat stuff -> greenhouse gases released -> climate warms -> more permafrost melts -> microbes eat more stuff -> feedback loop which eventually melts all the permafrost and triples the atmospheric carbon -> cataclysmic and permanent disruption of global weather patterns. It's not a cycle, it's a one-way phase transition.