There are many tipping points, and we dont always know if we’ve hit one yet or not. The drastic increase in sea temperature the last two years is possibly a tipping point we’ve passed, esp since the warmer the water is, the less co2 its able to absorb. OMAC shut down (if it happens) is possibly a tipping point, which will only feedback loop into warming waters.

Honestly, the permafrost melt is more likely to be the KO punch after one or more other tipping points accelerate it.