Friday, January 16, 2009

Revealed: the environmental impact of Google searches

Physicist Alex Wissner-Gross, a Harvard University physicist whose research on the environmental impact of computing is due out soon, says that performing two Google searches from a desktop computer can generate about the same amount of carbon dioxide as boiling a kettle for a cup of tea.

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 centers around the world that consume a great deal of power. Google is secretive about its energy consumption and carbon footprint. However, with more than 200 million internet searches estimated globally daily, the electricity consumption and greenhouse gas emissions caused by computers and the internet is provoking concern.

Banks of servers storing billions of web pages require power. A recent report by industry analysts said the global IT industry generated as much greenhouse gas as the world’s airlines - about 2% of global CO2 emissions. “Data centers are among the most energy-intensive facilities imaginable,” said Evan Mills, a scientist at the Lawrence Berkeley National Laboratory in California.

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 your 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.

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. Simply running a PC generates between 40g and 80g of CO2 per hour.

If your internet use is in place of more energy-intensive activities, such as driving your car to a shop, then that’s good. But if it is adding activities and energy consumption that would not otherwise happen, that may pose problems.

Everything has a carbon footprint, including this posting to this blog (and your reading of this posting).

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