I believe the tipping point usually refers to the release of Methane trapped in permafrost? Meaning the permafrost melts, releasing methane, and thus triggering a runaway greenhouse effect. Something like Venus.
This doesn't mean it's okay. Release of methane has always happened at the same time as major mass extinctions, possibly as the cause of it. It would create massive warming which would make large inhabited parts of the planet much less desirable, play havoc with the biosphere possibly making large areas of farmland unproductive, and in general being a massive economic drain and probably killing a lot of people.
Runaway global warming by melting methane clathrates is known as the Clathrate Gun Hypothesis: https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis
In previous mass extinctions, such as the End of the Permian, 251 million years ago, 96% of species were lost - due to a similar event: " A cataclysmic eruption near Siberia blasted CO2 into the atmosphere. Methanogenic bacteria responded by belching out methane, a potent greenhouse gas. Global temperatures surged while oceans acidified and stagnated, belching poisonous hydrogen sulfide. "
https://cosmosmagazine.com/palaeontology/big-five-extinction...
Nobody knows when/if the methane problem will happen. The ice/ocean thing can be modeled.