Apparently the question of how much greenhouse gas emissions can be traced to a single Google search is the hottest topic on the internets.
Research from U.S. physicist Alex Wissner-Gross says a single search produces 7g of CO2. Google says, nuh uh, it only produces 0.2g CO2 — less than your personal computer generates while running it. Lots more here.
There may be some value in drawing attention to the substantial carbon footprint of the IT industry, but by the time this kind of thing gets filtered through the media it ends up yet another story about how every human action is a source of guilt and shame. Now they want us to search Google less?
In fact, the emissions of Google searches is a goofy distraction. As Joe notes, the internet has been a phenomenal driver of energy efficiency and dematerialization. Imagine how much clueless driving around has been eliminated by Google Maps!