I didn't like it. I love Neal Stephenson, and I'm very concerned about climate change and think it's a great topic to tackle in a novel right now, but this was not a good use of 700 pages.
We need to be worried about climate change and thinking about what to do about it. But that's now why I read 700 page science fiction novels.
It was hard to finish. It took forever to get going, and you could make a case that it was character building... but geeze did it take forever, all the while we're learning about feral swine and other stuff that just doesn't matter. Then that same character bangs a queen before hiding out in an old mine in Texas for most of the rest of the novel.
And then a whole bunch of nothing about "the line of actual control" and stick fighting before making someone into a cyborg before he tries to destroy the effort to combat climate change. It's out there and it's bad!
Neal Stephenson, you can do (and have done!) so much better. I'm being generous with 2/5.