This seems extremely overblown. The idea that the Earth will become "uninhabitable" seems ridiculous at best: the Earth has been "habitable" for literally billions of years, even when the climate was vastly different than it is now. And if you mean "habitable by humans" rather than "habitable by any lifeform", humans in particular have adapted to an extremely wide range of climates, from frozen tundra to middle eastern deserts.
Perhaps you mean "habitable by 7-10 billion humans with today's civilization and level of technology and standard of living"? It's hard to imagine the Earth ever becoming completely uninhabitable by humans; someone will figure out a way to survive, no matter the catastrophe. But it won't be comfortable like today, and the planet probably won't support today's population levels.
I used the wiggle word of potential because the severity of these feedback loops is debatable, but I don't think it's overblown at all.
If a tipping point does in fact exist and we pass it, it means we will be on an irreversible course to indefinite warming of the planet. To make matters worse, a positive feedback loop implies an exponential growth, unless some sort of negative feedback loop kicks in to counter it.
It is estimated that we have warmed the planet by 1.21C so far (as of 2021) since pre-industrial era[1]. In the worst case scenario (RCP8.5), temperatures will reach 2.5-4.9C by 2100[2]. It's worth pointing out the impact of temperature increase is exponential as well, i.e. 2C global temperature increase will make severe weather events 4 times more frequent than a 1.5C global temperature increase. Some studies estimate that all of earth will be uninhabitable by humans if the global temperature reaches 12C above pre-industrial era[3]. I don't think it's overblown to say this is possible within the next few hundreds of years, especially if these feedback loops turn out to kick in and start rapidly pumping more CO2 into the atmosphere than we do.
[1] http://berkeleyearth.org/global-temperature-report-for-2021/
[2]: https://www.ipcc.ch/site/assets/uploads/sites/3/2019/11/SROC...
[3]: https://www.sciencefocus.com/planet-earth/how-hot-could-eart...
Where is your intuition for this coming from? Note that 12C rise in global temperature is a very different statement than 12C rise in average temperature of where you live. The temperature increase is applied non-uniformly. Also, the volatility in weather scales exponentially with global temperature increase. For example, 1.5C to 2C rise is expected to create 4 times more extreme weather events globally.
>Life would probably greatly resemble a Max Max movie
We don't need a fictional movie to see what life would be like. We are seeing glimpses of it already with these mega weather events hitting areas with a higher risk index such as the recent flooding in Pakistan that resulted in 33 million people impacted, ~600K people displaced, ~2,000 people dead, and ~10 billion USD in damages:
https://en.wikipedia.org/wiki/2022_Pakistan_floods
update to comment: I just saw this article this morning -- a new study on those tipping points I mentioned earlier in our discussion:
https://www.theguardian.com/environment/2022/sep/08/world-on...
I really feel like you're looking at a worst-case scenario, comparing it to living in modern civilization, and concluding that modern civilization can't possibly survive such an extreme climactic change, and then concluding that humans will go extinct. I'm sorry, but that simply does not logically follow. Civilization can be destroyed, but this is quite different from all humans going extinct. The Mad Max movies may be fictional, but they do show how humans are able to survive in very extreme conditions, which has been proven countless times in history by humans who really did survive in extreme conditions (go talk to the Innuit for instance). Will 7.5B humans survive in such conditions? Obviously not. Will a few thousand? Quite possibly. It was only a very small number of humans that crossed the land bridge from Africa to the Middle East to populate the rest of the world.
The greatest risk from climate change is not from natural disasters directly like in Pakistan, but the downstream effects of frequent severe weather events and warming of local climates. The loss of life and levels of migration will be much greater when critical infrastructure such as energy production, food production, and clean water supply, are impacted.
Either way, humans going extinct or being reduced by several orders of magnitude is a dire outcome, and we should be doing all we can to prevent it.
A temperature increase exists where earth will become uninhabitable by humans. One study mentioned above estimates that temperature increase is 12C. It could be higher or lower, but we don't really know without further studies on the topic.
Before reaching that temperature, life on earth will become a lot harsher for all due to the effects of climate change, and we should be doing all we can to avoid those harsher conditions, regardless of what we think the upper bound temperature for humanity to continue existing is.
Also, there are many potential feedback loops that may put us on an irreversible course towards the planet becoming uninhabitable in the future [3]. There is still a lot of scientific debate about when we will hit these feedback loops and how significant they will be. Where you stand on this issue is often what separates the doomer climate scientists that think we're passed these tipping points from the optimist climate scientists that think it's still avoidable or the feedback loops will not be too significant.
Most climate modeling focuses on the years of 2050 and 2100. What happens if we continue to make little progress by 2050 or 2100? As long as CO2e emissions are above net zero, warming will continue, and the effects will continue to get worse. Even if we do level-off CO2e emissions and stabilize at 2°C or 3°C, that temperature and all the extreme events, places that are no longer inhabitable, and lower crop yields that come with it will become the new norm, making life a lot harsher for future generations.
[1]: https://www.ipcc.ch/report/ar6/wg2/
[2]: https://link.springer.com/article/10.1007/s10584-011-0149-y
[3]: https://en.wikipedia.org/wiki/Climate_change_feedback