Stephenson's early stuff is good. It's not great though – he makes a big jump into great books all of sudden. There are some inklings of the great stuff to come in the early stuff, which makes them worth reading.
I was worried that this book was going to be cliched environmentalism, but Stephenson avoids becoming cliche, for example he rips on the government environmentalist, do-good, liberal types:
And the do-gooders in the universities:
His environmentalist even rips on other environmentalists (or "duck-squeezers"):
Debbie insisted on following the rhythm of the waves. Typical duck-squeezer sex: slow, frustrating, in tune with nature.
Stephenson has found a way to write an environmentalist novel that doesn't put off non-environmentalists – that's the inkling of genius. His environmentalist isn't out to save the earth so much as he's out to piss off people and to fight – it doesn't really matter why. In that sense the character comes across as almost neutral on environmental issues and then the good science writing takes over and carries the book. Anyway, if you're looking for something to pass a long flight or to read on the beach, then enjoy.