Tarm: I'm getting a little tired of people saying it helps the environment to buy digital copies of everything. Almost all electricity produced is definitely not good for the environment and producing computers ain't either. Using "dirty" electricity and buying new digital devices to use digital copies of stuff on ain't much better for the environment than physical copies. Not to mention most digital devices that are thrown away end up poisoning said environment.
I agree it's a little better but not as much as people tend to think.
Magnitus: I doubt that. Between the energy that got wasted during the manufacturing process (cutting down the tree, mashing it's content into pages, printing the content on the said pages) and during transportation, the energy spent reading the material on some e-reader will be minor in comparison.
Furthermore, energy has the potential to be generated substainably (solar, wind, hydro, etc).
However, cutting down a tree (plus the ink) to make a book will always be what it is.
All would be well and good if people only read ebooks on a device purely created for that and it didn't need to be replaced until it broke.
But that's in a perfect world. People read ebooks on all sort of devices and people also replace those devices all the time.
I wasn't only talking about ebooks either. More and more stuff get digitalised all the time. Music, various services, movies and other things. We're living in a digitalised revolution after all.
Cutting down a tree and making books of it isn't as bad as damming a river to make a new power plant for example. The paper can be recycled and a new tree planted while the environment on the river is damaged for a very long time.
Sorry for the rant. Sometimes I get irritated of that it's generally thought that to digitalise as much as possible will automatically save the rainforest or something.