Sony Reader versus books: what's greener?

Round two: carbon running costs
Reader
The Reader surely wins here, right? To get a new book, you just download a few zeros and ones from the web. No printing, no transport. But running the Reader requires energy in more ways than you'd think. It uses electricity to charge its internal battery, to power the PC you use to download new titles, and to run the servers that host the e-books.

I think we can write off the Reader's own battery as a big power suck. Sony says the battery lasts 7,000 page turns -- the only time it draws power -- so you'll only be recharging every 14 books or thereabouts. Even if the Reader has a huge capacity battery (Sony won't tell me how many mAh it's rated at), it's still going to use very little power when compared to your mobile phone.

It's hard to say how much energy your PC and a server consume when downloading a Reader book, because there are so many variables. One indicator is a 2003 report by Forum for the Future, which compares the carbon footprint of CDs purchased in shops and MP3s downloaded online. To purchase 56 minutes of music, the CD route produces 1.6kg CO2 and the MP3 download produces just 0.7kg CO2.

Comparing books to CDs is like comparing apples and pears, but I'd wager the Forum for the Future findings hold broadly true for books and e-books. Factor in the fact that file sizes for eBooks are smaller than most MP3 singles, and the odds look even more stacked in the Reader's favour.
Score: 4/5

Books
The brilliant simplicity of the book is that, once it's been produced, it consumes no energy to run.

The printed book, however, loses out against the Reader when you apply the multiplier effect. As we've seen above, each new book comes with a carbon footprint in the region of 2.5kg CO2. So if you buy 50 new books a year you're creating 125kg of carbon dioxide every year: more than 11 times the average Brit's carbon footprint.

You could also factor in the carbon cost of lighting and heating bookshops. But I think that would be stretching the definition of a book's carbon footprint. With all carbon accounting, there's the question of where you draw the line. And if you begin counting bookshops' energy use, than surely you have to start factoring in the heating and lighting for the offices where the Sony eBook Store crew work? No, I think we can say the main carbon 'running cost' of the printed book comes from paper production, printing and transport.
Score: 3/5

Verdict
Another close-run round, but the Sony Reader appears to have the edge. Despite the fact the Reader needs electricity to run, the carbon footprint of acquiring new printed books is comparatively large. So the more books you consume, the greener the Reader looks compared to the printed word. Reader wins.