Google issued a retort on its Official blog to a Times of London piece where Harvard physicist Alex Wissner-Gross alleges that every two Google searches generates the same amount of carbon dioxide as boiling a kettle of water, about 15g.

According to the Times report, users conduct about 200 million searches a day globally via Google. The article's authors say the waste comes in the method Google's search engine operates. A user's search request is delivered by the server that produces the fastest answer, causing servers thousands of miles apart to compete against one another and use more energy.

Google claims that it has the most energy-efficient data centers in the industry, which minimizes the energy used per Google search and says that its searches are equivalent to only 0.2 grams of carbon dioxide. The company claims on its blog that during the time it takes to conduct a Google search, an individual's PC uses more energy than does Google in producing the result.

This TechCrunch.com item via The Washington Post attempts to shed a bit of light on the argument. A 500-page book has a carbon footprint of 2,500 grams, compared to the 7.5 or 0.2 grams a single Google search produces. In addition, a person can conduct a Google search in lieu of traveling somewhere to seek out the information. While the author admits Google can probably become more energy efficient, he believes the tone of the Times article to be alarmist.