As someone else already put it, Kim Stanley Robinson's "Forty Signs of Rain" is like the real world version of "The Day After Tomorrow" and I wholeheartedly agree with that point of view. The difference however is probably more subtle than it meets the eye. In the film, everything gets graphically exaggerated whereas here, and thus in the real world, things are much more likely to be less spectacular but its implications far more complex, tragic, difficult to assimilate, to accept and to live (or not) with. It's not a matter of avoiding a catastrophe that didn't happen yet. It already begun and, should we accept the challenge, we're already poised for damage control.
"Forty Signs of Rain" tells many tales at once, with a common ground: the destiny of the biosphere and how the world we live in is quickly becoming quite uninhabitable. It also tells a story of how science gets done and how the scientific process truly unfolds, how scientists are not as cold hearted as many people suspect they are, how buddhism can shed new light on science, how capital makes it all the more difficult and even how a "Mr. Momhood" type of father deals with his baby son on a daily basis while trying to help a senator do the right thing.
This is a book which most of all tries to propagate important ideas. Never boring, but rarely amusing, it gets its message across loud and clear, even if it objectively lacks in the plot and story department. If, like me, this is the first Kim Stanley Robinson book you're planning to read, this nevertheless felt like a pretty good introduction to the author.