This factors in some feedback loops which most sudies to date have ignored. Note, that it excludes extra warming caused by all the additional water vapour in the air.
For context, studies suggest that the largest extinction event in Earth’s history (so far), the Late Permian Extinction Event, saw temperature rises of around 8°C.
Every time I see someone I know having a kid, I just wonder why, do they have no foresight? Driven by this selfish desire to duplicate themselves they never bother to ask what that child’s life is going to be like. Literally bringing them into a collapsing world.