This one was hard to score. I have ended up at 4 stars with caveats.
Stan uses the bones of his earlier works (in particular The Mars Trilogy) to speculate how we might get out of the coming climate apocalypse as a species. This is definitely important speculation and I like how he weaves a pile of different things together (finance reform, ubi, collectives, job guarantees, eco-engineering etc) to get there.
However, I found this a difficult read. It starts off strong with a single PoV of someone suffering through a mass death in a heatwave. Then it just loses the thread of human interest. The characterisation is presented in a very flat affect. It's difficult to relate to the characters because of this. As the book goes on the characters just take a back seat to laying out the events.
Further, he has a thing where he is dropping little vignettes in. Some of these are for the purposes of explaining something but some just left me scratching my head. After about halfway I was prone to skimming these.
In summary a recommended strong ideas and speculation book but may be a difficult read due to being light on the character development progress side.