Wouldn't crossing these tipping points also accelerate toward more warming? Like the thawing of permafrost in the northern regions would possibly release a huge amount of methane, creating a greater greenhouse gas effect.
What you're describing sounds like the Clathrate gun hypothesis, which would be moderately terrifying: <https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis>
If it does happen it shifts man-made climate change from an unprecedented humanitarian disaster to a possible global extinction event. The last time it happened it may have wiped out 81% of marine species and 70% of terrestrial vertebrates.
But, there are so many terrible consequences of climate change that are near certainties for us to waste valuable focus and mental energy being terrified of the merely hypothetical.
The point of climate policy is not to stop global warming, in the sense of cooling the planet in an absolute sense. It's to slow it down, cooling it in a relative sense.