The Times and Telegraph have picked on some rather dubious stats on Google energy use:
a typical search generates about 7g of CO2 Boiling a kettle generates about 15gbut
Wissner-Gross has also calculated the CO2 emissions caused by individual use of the internet. His research indicates that viewing a simple web page generates about 0.02g of CO2 per second. This rises tenfold to about 0.2g of CO2 a second when viewing a website with complex images, animations or videos.
So client-side, a search costs 0.02g/s - to get to 7g you look at it for 350s, or nearly 6 minutes. But hang on:
A separate estimate from John Buckley, managing director of carbonfootprint.com, a British environmental consultancy, puts the CO2 emissions of a Google search at between 1g and 10g, depending on whether you have to start your PC or not. Simply running a PC generates between 40g and 80g per hour, he says. of CO2 Chris Goodall, author of Ten Technologies to Save the Planet, estimates the carbon emissions of a Google search at 7g to 10g (assuming 15 minutes’ computer use).
He's using it for 15 minutes per search? That gives 0.01g/s, or half the other chap's estimate.
Google's data centre's are carbon neutral, so it is only the client end you do have to worry about. However, breathing generates about 6g of Carbon every 10 minutes. Or about as much as they estimate computers do.
So I suggest you hold your breath while you search Google, to offset your carbon use. As searches return in well under a second, whatever these newspapers say, this shouldn't be any hardship. Or search from your Android or iPhone instead.
Update: Urs Hölzle gives some actual figures for searches energy use