I work for a printer, and we've just been Forest Stewardship Council certified:
http://www.fsc.org/
so that's one datapoint in the renewable nature of books printed on paper.
For ebook readers, while the metal is pretty much infinitely recyclable, plastics degrade in any recycling technique I'm aware of and so have a fixed life cycle, but as a counterpoint, glue &c. in printed works isn't recoverable.
As regards ebooks working better to disseminate information, well, a paper book in a library achieves that quite well, so that nibbles away at that a bit.
That said, Kovid's point of the convenience aspect is a good one, and if people didn't spend the money on an ebook reader they'd probably get a PDA or MP3 player or some other toy, so it's not an absolute cost.
William