Carrying out two Google searches from a desktop computer can generate-about the same amount of carbon dioxide-as boiling a kettle, say U.S. researchers.
A typical search produces about 7grams of CO2 compared with 15grams for a kettle.
During a Google search, several servers, which can be thousands of miles apart, compete to return the results fastest.
Alex Wissner-Gross, a Harvard physicist, said: 'Their primary concern is to make searches fast and that means they have a lot of extra capacity that burns energy.'