2312 can be thought of as the spiritual sequel to the Mars trilogy, and in fact reuses many of the settings and plot elements from that fantastic series. While it was gratifying to see Robinson returning to his roots and to explore more of the most realistically portrayed hard science fiction about humanity's future in the solar system, this book has a lot of issues.

A friend of mine is reading Red Mars right now, and while he's jazzed about how hard the science is, he's put off by the fact that nothing ever really happens (the "fiction" part). I mean, lots of things happen; but relatively little feels momentous or exciting. One can be forgiven for thinking it's just a Diary of Shit That Happens on Mars. Robinson's characters are all terminally polite and well-spoken, even the ones that are the most unbalanced emotionally. Their conflict is so measured, so reasonable, and there are no outright villains or heroes to speak of. Robinson's books have a resulting aura of calm around them that I tend to find very palatable, but it works better in some places than others.

Red Mars and the rest of the Mars trilogy featured genuinely empathizable characters that you get to know over decades and centuries as they literally build a world. The relationships they form likewise last decades, and are some of the deepest and most affecting that I've come across in any literature, science fiction or otherwise. I'm thinking especially of the reluctant romance between Anne and Sax that takes an entire trilogy to play out.

2312 is a romance story as well, but it never got its hooks into me. Maybe the characters are to blame: Swan is an emotionally unstable artist from Mercury, and Wahram is a plodding, stolid politician from Saturn. Their planetary origins is Robinson's not-so-subtle way of continuing to explore the ancient personality classifications, and the two protagonists are pretty faithful representations of the mercurial and saturnine templates. It's cute, and Robinson does an excellent job building each of their characters over the course of the background action / mystery plot, but I never really bought their attraction to each other on a visceral level, and Swan is so acutely unlikable for the first 80% of the book that it's hard to understand what Wahram could possibly see in her.

There's still plenty of good bits, mostly Robinson's always effective evocation of setting, especially landscape and cultural history. Inveterate socialist that he is, Robinson imagines a future where capitalism remains entrenched on Earth three centuries hence, despite the system failing so many of the people it serves. The plan to "fix" Earth to ensure the safety of the rest of the solar system, brought up so often in the Mars trilogy, is the meta narrative that ties together the rather weak mystery plot involving attacks on a series of space settlements.

Narrative chapters are interleaved with chapters of free association-style lists on various themes left as an exercise for the reader; or bland expository sections that are supposed to read as if they're sentence fragments copied and pasted from a series of future history texts. Many of these were interesting, but the list chapters often felt out of place, and I would have preferred the exposition to take place in the main narrative. There was some of this in the Mars trilogy too, but it didn't seem so intrusive there for whatever reason, perhaps because, as a rule, it explained significant events the characters weren't around to witness, and occurred in the same chronology as the main plot.

With the exception of the disappointing The Martians and the interminably boring The Years of Rice and Salt, this is my least favorite Robinson novel. I really can recommend it only for those who loved the Mars trilogy and are anxious to find out what's next in Robinson's solar system.