The New York Times asks which is greener. Verdict:
Some of this math is improving. More and more books are being printed with soy-based inks, rather than petroleum-based ones, on paper that is recycled or sourced from well-managed forests and that was produced at pulp mills that don’t use poisons like chlorine to whiten it. The electronics industry, too, is trying to reduce the use of toxic chemicals, and to improve working conditions and worker safety throughout its far-flung supply chains.
So, how many volumes do you need to read on your e-reader to break even?
With respect to fossil fuels, water use and mineral consumption, the impact of one e-reader payback equals roughly 40 to 50 books. When it comes to global warming, though, it’s 100 books; with human health consequences, it’s somewhere in between.
All in all, the most ecologically virtuous way to read a book starts by walking to your local library.