What is the carbon footprint of the Internet?

The Internet produces 300 million tonnes of carbon dioxide a year, equivalent to everyone in the UK flying to America and back, twice over. According to an article published today by UK newspaper The Guardian, data centres account for around half a per cent of all global carbon emissions, with the total estimated output for all Internet-related activity amounting to around one per cent of global man-made CO2. That's equivalent to all of the fossil fuels burned in...