Google Rebuts Claims about CO2 Cost of Searches

The UK’s Times reported last Sunday that doing two searches on Google uses about as much energy as boiling a kettle of water, an allegation that Google is denying on their official blog. The information in theTimes article was supposedly based on research by Harvard University physicist Alex Wissner-Gross and delves into the “secrecy” of Google’s energy consumption and carbon footprint.

From the Times Online:

While millions of people tap into Google without considering the environment, a typical search generates about 7g of CO2 Boiling a kettle generates about 15g. “Google operates huge data centres around the world that consume a great deal of power,” said Alex Wissner-Gross, a Harvard University physicist whose research on the environmental impact of computing is due out soon. “A Google search has a definite environmental impact.”

Though Google says it is in the forefront of green computing, its search engine generates high levels of CO2 because of the way it operates. When you type in a Google search for, say, “energy saving tips”, your request doesn’t go to just one server. It goes to several competing against each other.

It may even be sent to servers thousands of miles apart. Google’s infrastructure sends you data from whichever produces the answer fastest. The system minimises delays but raises energy consumption. Google has servers in the US, Europe, Japan and China.

Google responded by explaining on their blog why the “7g of CO2” number is “many times too high”.

Google is fast — a typical search returns results in less than 0.2 seconds. Queries vary in degree of difficulty, but for the average query, the servers it touches each work on it for just a few thousandths of a second. Together with other work performed before your search even starts (such as building the search index) this amounts to 0.0003 kWh of energy per search, or 1 kJ. For comparison, the average adult needs about 8000 kJ a day of energy from food, so a Google search uses just about the same amount of energy that your body burns in ten seconds.

In terms of greenhouse gases, one Google search is equivalent to about 0.2 grams of CO2. The current EU standard for tailpipe emissions calls for 140 grams of CO2 per kilometer driven, but most cars don’t reach that level yet. Thus, the average car driven for one kilometer (0.6 miles for those in the U.S.) produces as many greenhouse gases as a thousand Google searches.

On Monday, January 12th, Alex Wissner-Gross denied singling out Google, saying his study focuses on the internet in general and that the Times apparently had an ax to grind with Google. Tech News World has the scoop:

“Our work has nothing to do with Google. Our focus was exclusively on the Web overall, and we found that it takes on average about 20 milligrams of CO2 per second to visit a Web site.”

And the example involving tea kettles? “They did that. I have no idea where they got those statistics,” Wissner-Gross said.

Wissner-Gross, who manages the Web site CO2stats.com to help educate people about energy efficiencies on the Internet, has been inundated with press requests since the Times story was published. The Times quoted him correctly in the story as saying, “A Google search has a definite environmental impact” and “Google operates huge data centers around the world that consume a great deal of power,” he confirmed.

“I don’t think anybody would disagree with those statements,” Wissner-Gross said. “Everything online has a definite environmental impact. I think everybody can agree on that, including Google.”

As Fast Company points out amidst all of these accusations and rebuttals, the real story here is that there is, and will continue to be, dialogue about the energy costs of the information age. It’s a reminder that there’s a carbon cost to everything we do on the computer, from watching videos to playing games. Awareness is spreading about how our use of such technology has an impact on the earth’s resources, and that will undoubtedly continue in the years to come.

Link [Times Online] + [Google] + [Tech News World] + [Fast Company]

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