Most people will not keep their ereaders long enough to read 90 ebooks that they would have bought in DTB form. Currently I read three to four books on my NOOK per week, but only about half are purchased (or would have been purchased as DTB - free ebooks, et al). Most of my reading is done courtesy of the public library - and has been for several years. I can count on two hands the new DTBs I've purchased or been given in the last four years. I grew up in the public library and in our last home, we had limited shelf space, so I quit buying books. Figuring out what to discard in order to house the new one was far too emotionally taxing. (And presuming that I ever get a job again, I'll be reading more like one or two books per week. )
I couldn't quit reading and I rediscovered the public library. Now, most of my library books are electronic, but I'd be taking them as DTBs if I didn't have a NOOK.
I expect to keep my NOOK for four to five years, but most users here admit that they don't expect to be using the same ereader (due to new technologies) in one or two years. Very Few people will read 90 books in one year. More will read one book per week, making them carbon neutral after almost two years - about the same time they replace the reader.
Like you, I didn't buy NOOK to be green, although I would love for that to be true. We do a lot of small things (no paper napkins, 12 rolls of paper towels last us well over a year, we recycle everything we can - meaning a biweekly trip over to the local construction resale warehouse to recycle what our city doesn't collect, we buy used for anything that we can find acceptable quality used versions, I use vinegar as a cleaner, etc...) but I know we could do way more.
I'd love to believe my NOOK addiction is green, but in my case since I bought very little of my reading material before, my NOOK is probably the antithesis of green.
Green is my most hated color.....if anything I owned turned green, I'd flush it.
If you really want to be green, the NST is the way to go because it uses far less energy than the other Nooks. The only time that it needs energy is when you turn the page. Also, I haven't been able to find the CO2 emissions for any of the Nooks, but an iPad produces 2.5 grams of CO2e per hour of use, so we can assume that NC is similar. One physical book is responsible for "a net 8.85 lbs" of carbon emissions over the course of it's life (production, transportation, and retail).
Also, there was a study done not too long ago that proved that consumers only needed to read 23 eBooks to make they're e-reader greener than print versions.
Conversations on "green" products always confuse me.
The concept that something can't be green because of the production/transportation/storage/retail environment of a certain product as an argument against it is moot. EVERTHING involves production/transportation/storage/retail environment. EVERYTHING YOU BUY AND USE EVEN IF YOU GREW IT YOURSELF! Those seeds had to come from somewhere as do everything you might use to preserve/can or cook it with. Even animals have to be transported/fed/housed and they produce methane gas like crazy.
We grow cotton and FIL owns a cotton gin...and what could be greener than cotton, right? But...the field has to be tilled and prepared/fertilized, sown and treated for boll weavels(major restrictions on cotton grown with boll weavels so you don't want them) and weeds, then stripped or picked,ginned,bagged, tagged, stored and transported to a storage facility that then transfers it yet again to a buyer where it is then made into thread,stored,transported again to where it is made into the final product that has to be produced/stored/transported yet again to a retailer where it is stored yet again.That's an enormous amount of deisel/propane gas, electricity and chemicals, not including the plastic used to bag bales of cotton, module tarps, plastic twine/special spray paint (to keep track of cotton before it is ginned) labels, the machinery required for all these processes.
There is so much electricity/gas involved in the process it's crazy. But at least cotton is an easily reproduced product as compared to a tree. And most of the cotton used in this country is grown overseas and shipped here. and that's a whole nuther process/cost
So I don't feel particularly ungreen using my NC. I read over 100 books a year and buy just as many as I did DTB's and read free ones as frequently as I did before as well. My NE1 is finding a new home with my sister so it's not heading for a landfill anytime soon either.