Web surfing on your coffee break: double climate trouble?

When you nip away from your computer for a cup of coffee, you can potentially accumulate a fair amount of bad environmental karma. You can overfill the kettle and thus use more energy than you need to to boil the water; you can while away a minute or ten chatting with your colleagues, but not have your monitor set to switch off after a few minutes of inactivity. But it seems that even a bit of web-surfing back at your desk can also harm the environment, albeit in less immediately obvious way. The computer on your desk is not the only one that you’re relying on for your browsing; to function, the internet needs lots of powerful, power-hungry computers, working hard 24 hours a day as they shuttle the latest celebrity news and Twitter updates from continent to continent, computer to computer. Add the power output of all of those servers and routers to the electricity used by the computer on your desk, and it starts to add up. Today, The Times reports on calculations by Alex Wissner-Gross (who also has his own say here) that a typical Google search generates about 7g of CO2. Since boiling the kettle for your cup of coffee produces about 15g of CO2, it doesn’t take much for you to double your environmental impact with a bit of procrastination..
I have no way of checking these figures (indeed, the article admits that they’re not based on anything provided by Google themselves Update: Hypocentre points us to Google’s response). I have no reason to doubt them either, of course, but I’m not sure how useful these numbers really are given that as I read it, the calculation is not simply for the Googling alone, but includes your own computer, which would probably be on anyway – the real question is, what’s the additional impact of using the internet? Still, it’s another example of the total environmental impact of what we do being harder to assess than we may think. If we’re thinking green, we might consider the computer on our desk, but possibly not the whole information infrastructure behind it – an infrastructure that is already generating more CO2 per year than the oft-demonised airline industry. It’s easier to grasp the harm that a jet airliner can do, because you see it overhead, and you fly places in it; the server farm, in contrast, is hidden away and detached from what we use it for.
Similar things seem to crop up all the time: food grown locally using mechanised farm equipment and fertilisers may sometimes have a bigger carbon footprint that crops grown the old-fashioned way overseas. The other week Maria informed us that home baking bread may not be very eco-friendly either. Making informed choices about reducing one’s carbon footprint seems fraught with difficulty, with good information often difficult to find. If anyone knows of any good sources of such calculations, let me know in the comments.