In 2011 the Green Press Initiative issued a synthesis of various reports on The Environmental Impacts of eBooks and eBook Readers:
"Since the data suggests that sales of E-books are likely to increase while sales of printed books are likely to decrease, it is logical to question the environmental implications of this transition. In 2008 Green Press Initiative and the Book Industry Study Group commissioned a report on the environmental impacts of the U.S. book industry which included a lifecycle analysis of printed books. That report concluded that in 2006 the U.S. book industry consumed approximately 30 million trees and had a carbon footprint equivalent to 12.4 million metric tons of carbon dioxide, or 8.85 pounds per book sold.
"Determining the environmental impacts of an E-book presents a challenge that does not exist in estimating the impacts of a paper book. That challenge is the fact that user behavior will significantly influence the impact of an e-book. This is due to the fact that the manufacturing of the E-reader device accounts for the vast majority of an E-books environmental impact. Because of this, on a per book basis, a reader who reads 100 books on an e-reader will have almost 1/100th of the impact of someone who reads only one book on the same device. Additionally, two readers who each read the same number of books per year, can have a very different per-book environmental impact if one buys a new E-reader every year while the other keeps his for four years before replacing it. Because of the impact that user behavior can have on the environmental impact of E-books, any analysis will either have to make assumptions about the behavior of a “typical” reader of E-books, or else identify a break-even point in terms of the number of books that must be read on an E-reader to offset the environmental impacts of a corresponding number of paper books. However even this can be confused by the fact that it is not clear that reading one E-book offsets one paper book. For example, the ability to instantly download any book at any time may encourage E-reader owners to read more books in which case each e-book read would not necessarily correspond to a printed book that would have been read. Additionally someone who buys a printed book and later lends it to a friend to read would in effect halve the environmental impact of reading that book. As such any analysis should strive to account for this and determine a break-even point in terms of “printed books offset” rather than E-books read. Additional complexity is added by the fact that most E-readers can be used for a variety of tasks other than reading books. For example, most can read newspapers and magazines in addition to books and some E-readers can also read blogs and surf the internet. Tablet computers can allow a user to check e-mail, play games, view photos and videos, listen to music and surf the internet in addition to other things. Thus for the owner of a Tablet computer, who only spends 10% of his time using the tablet to read books, it would seem reasonable to assume that only 10% of the manufacturing impact of the tablet should be counted towards the impact of that users E-books. . . .
"As the number of printed books that the E-reader offsets increases, so do the benefits of that E-reader. At some point these gains offset the impact of manufacturing and using the E-reader. This “breakeven point” will be different for different metrics of environmental performance but for most it is likely somewhere between 30 and 70 printed books that are offset over the lifetime of the E-reader. For greenhouse gas emissions this number is probably between 20 and 35 books while for measures of human health impacts the number is probably closer to 70 books. In assessing the impact of an E-reader the idea of printed books offset must be carefully considered. As mentioned above, if the owner of an E-reader reads more books because of the ease and convenience of downloading a new title, then every book read on the device does not necessarily correspond to a printed book that is offset. Additionally the numbers in the figure above are based on a very simple comparison that is not likely to be replicated in the real world. The assumption is that the reader would either purchase a new printed book once and not share it with anyone else or that the reader would read the books on an E-reader and only use the E-reader for reading books. If a person would normally share a printed book with others, buy some used printed books, or borrow many of the printed books from the library then the numbers would need to be adjusted to account for that. Additionally, if the E-reader is used for other activities such as watching video, browsing the internet, checking email, or reading magazines and newspapers, it is unfair to assign the full impacts of producing the E-reader to E-books. More research is needed on typical user behavior in terms of time spent reading E-books verses other activities on E-readers and Tablet computers in order to make a more accurate comparison. If the trend of the iPad stealing market share from the Kindle continues, it seems likely that users will spend more time on the other activates that tablets like the iPad are optimized for. Additionally, if someone already owns a tablet computer or an E-reader, the marginal impact of downloading and reading an additional book is quite small. Thus for someone who already owns a device capable of reading E-books, the best choice from an environmental perspective would likely be to read a new book on that device."