Updated at 12:20 a.m PST January 12 to include Google comment.
Worried about the carbon footprint of your Google searches?
A Harvard University physicist says a typical search on a desktop computer generates about 7 grams of carbon dioxide, which is comparable to bringing a kettle to boil, according to a report Sunday in The Times of London. And while that doesn't sound like a lot, the report notes that Google handles about 200 million searches daily.
"Google operates huge data centers around the world that consume a great deal of power," Alex Wissner-Gross told the newspaper. "A Google search has a definite environmental impact."
The global IT industry generates about 2 percent of global carbon dioxide emissions, or about as much greenhouse gas as the world's airlines, according to a recent Gartner study cited by the newspaper.
Google disputed that report late Sunday evening, saying in a blog that the "time it takes to do a Google search, your own personal computer will use more energy than Google uses to answer your query." The blog also noted:
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.
Google is a board member of a new group called Climate Savers Computing Initiative, a coalition that aims to reduce computing power consumption by half by 2010. It will do that largely by encouraging member companies like Google to turn off computers when they're not in use. The company said that if it reaches its goal, it would be the equivalent of taking 11 million cars off the road.
The search giant's Google.org philanthropy released numbers and policy recommendations in November on how the U.S. could wean itself from coal and oil for electricity generation and nearly halve its gasoline consumption by 2030.
Google first introduced its 2030 energy road map last October; CEO Eric Schmidt, an adviser to President-elect Barack Obama, made speeches last year, calling on the federal government to show more leadership on climate change by fostering clean-technology businesses.
Schmidt told the Corporate EcoForum last year the company's plan is to reduce global demand for oil and help to generate new white- and blue-collar jobs by investing in solar, wind, and geothermal energy projects.
Steven Musil is the night news editor at CNET News. Before joining CNET News in 2000, Steven spent 10 years at various Bay Area newspapers.
By Steven Musil