In view of the worldwide size of book publishing we should also keep an eye on the CO2 footprint of book publishing. The Italian association of publishers gave a brief overview of the likely CO2 footprint the printing of a book causes. Their best guess is at ½ a kilo of CO2 on average. For simplicity of calculation and assuming that an editors’ association is unlikely to overstate the amount, let us assume it is 1 Kg CO2 per book. The most CO2 is consumed not in the book production but in the transport of the items, machinery and personnel involved in producing, editing, selling etc. Of course, paper is recycled to a large amount. Certified sustainability of paper from trees has become a standard in most countries.
Nice twist to the issue: your own library at home has become a CO2 storage, if you keep them or lend them or pass them on to others. Reading can be a little bit addictive and buying books as well. Reading online or electronic books reduces your CO2 footprint. The best way to imagine the reduction of your CO2 footprint, however, is to buy or to borrow a book on travelling which replaces the actual journal by reading on the couch. Yes, being a couch potato is good for the planet, and if you want to buy a book, walk to the book shop or the library if possible. If you enjoyed flying previously shift over to buying books on planes, airports, clouds in images or stories that involve extensive travelling instead for the sake of your own CO2 footprint and future generations.
Even a book will need somehow wood as input, many alternative ways of leisure time or professional activities are worse in terms of CO2 footprint. Any e-book, e-journal or e-newspaper is even better for the planet, especially if we think of the millions of paper copies across the world that are printed but never sold. Knowing your market is crucial to reduce misallocation of ressources. E-books are so much easier to store as well using regenerative energy for the content servers around the world. 
