We've previously heard of schools and colleges using e-books to cut costs and save paper, but had never really considered their environmental impact... until now.
According to a study by the Cleantech Group, Amazon's Kindle accounts for far less CO2 output over its life than consuming comparable numbers of paper books would.
Lots and lots of books
The research suggests a Kindle's lifetime production and running costs are responsible for 168kg of CO2, while printing and distribution of three books a month for four years would pump out 1,074kg.
The arbitrary nature of the numbers is underlined by the further assertion that consuming printed matter to a sufficient degree to match the Kindle's maximum capacity would chalk up a whopping 26,098kg of CO2.
Half a book?
Silly numbers aside (actual reading habits in the long term are surely what matter), the study's bottom line is that Kindle users can break even in CO2 terms if they use it to read 22.5 books over the device's lifetime.
Which leads us to speculate that the 0.5 of a book has to be the copy of 1984 Amazon swiped from paying customers in the dead of night.
As for the slightly depressing e-book-induced loss of personal libraries to be cherished and shared with others, we're not even going to go there.