Look. It has already happened. Like the man in the video (thx, btw; you're just like us!) said, the 1.5 degree mark was passed in 2016. The evidence was compelling enough by the early 80's (when Reagan had the solar panels removed from the White House) Everything since is corroboration. There is nothing more to prove: it's a matter of watching it play out.
What's not possible:
Halt or reversal of the manifestations.
Retention of low-lying coastlands.
Saving any part of any glacier - and that means a lot of dry riverbeds.
Saving many thousands of animals, bird, insect and plant species.
What's still possible:
Rescue, relocation and protection of vulnerable human populations.
Developing alternate - more efficient - food sources, heating, cooling, lighting, production, transportation and communication.
Developing and expanding high-density, efficient and self-sufficient housing.
Some mitigation of local damage.
Large-scale geoengineering. Some very big concerns there!
You know the most bizarre, the most surreal thing about these endless panel discussions? The moderator always smiles and says "Now, now, let's all be polite and hear the crackpot out," as if the crackpot and the expert were both there for their equal entertainment value. In a sane world, the moderator, presumably having had the research team's homework handed to him ten minutes before air-time, wouldn't be fairnadbalanced - he'd be hysterical. It's only the end of the frickin world....