Can I be green and surf the net?

Somewhere in California (and soon to be in India and possibly Iceland) there are vast tracts of hulking warehouses containing thousands of energy-guzzling servers – it's farming, but not as depicted in The Archers . Server farms provide the network to transmit websites. They are powered by electricity, predominantly from coal-fired power stations. Add in the energy required to make your PC in the first place and computing is responsible for 1bn tonnes of CO 2 each year – more emissions than aviation. In pollution terms, using t'internet could be your equivalent of an Arkwright mill at full throttle during the Industrial Revolution. Last month some headlines suggested that a Google search generated 7g of CO 2 – the same as making a cup of tea. This left the eco-minded home worker in a real quandary: I chose the cup of tea. Later Google corrected this to 0.2g per search. But still, it all adds up. The latest research suggests that you create 20mg of CO 2 per second per visit to a website. The more whistles and bells on the site the higher this gets – up to 300mg of CO 2 per second for one with video content. Running an avatar in Second Life uses more electricity than a live person in Brazil. Ask yourself: is this watt necessary? Employ a spam filter, too. In 2008 an estimated 62 trillion spam emails were sent globally, creating the same greenhouse gas emissions as 3.1m passenger cars. I know what you're thinking: what's wrong with a reference book? Well, US academics remind us that driving a mile and back to the library produces 100 times more greenhouse gas emissions than a web search. Remaining ignorant is carbon free.