I'm not sure what this really means. It seem clear that adaptation will happen, and that may mean some amount of migration by the end of the century which is personally upending for a lot of people but not unprecedented in the last century.

Desalinization is showing a lot of progress recently and will likely be much more affordable in the next 20 years. Lithium prices are dropping so we might have a path for ward for grid scale power storage, which would be huge. Major flooding and heat risk that effect large numbers of people are concentrated in a few spots so it seems like infrastructure can be built to handle flooding, and architectural changes coupled with cheaper renewable power can address the heat.

We collectively managed to tackle the ozone layer issue before Australia got cooked, so it think there's precedent here. Technology is getting better and we collectively have more resources to bring to bare now. Its not going to be easy or fun, but probably won't be an unraveling of civilization either.