Steve O’Donnell over at The Hot Aisle calculates that the amount of CO2 required to post a blog on blogs.sun.com (as a worked example) is the equivalent of driving 7.6km in a Prius car.
Here’s Steve’s example.
As an example, this is how I calculated the surpisingly high blog post on blogs.sun.com number:
We are hosting 66183 blogs in 3 years, running on two T2000 (the best servers you can get when it comes to power efficiency).
A pair of Sun Fire T2000 servers draws 2*320Watts. Double that number for cooling and infrastructure, so you need 33628KWh in three years. That’s 0.5KWh for every blog! One KWh electral power created in a coal power plant creates 1700 grams of CO2 – so the global warming effect of this blog is comparable to a runner running 21 kilometers (or sitting in front of his computer for one whole day).
Steve got the details from this German language post by a chap called Rolf.
We better get tree-planting, eh?