
Google say that one search uses 0.0003kWh of energy which contributes 0.2 grams of CO2 to our greenhouse in the sky. Google say that one persons Google use for an entire year emits the same amount of CO2 as washing their clothes for a year. Most of Google's energy usage comes from the huge network of servers and data centres it requires to maintain their services.
Google's figures differ somewhat from a Harvard University physicist who told The Times he works a typical search to generate 7 grams of CO2. Bringing a kettle to boil uses 14 grams of CO2 or 2 Internet searches.

While we're on the subject of our carbon footprints, a recent study estimated that the global IT industry generates the same amount of greenhouse gas as the world's airlines. Before we know it we'll be able to measure the CO2 emitted from every inch of our lives.