The environmental cost of a Google search

Monday, January 12, 2009 | 02:06 PM ET

By Paul Jay, CBCNews.ca.

A Harvard physicist and green-website founder's assertion that running two Google searches released the same amount of greenhouse gases into the atmosphere as boiling a kettle of tea has caused a tempest in a you-know-what.

Type in "google search kettle" in Google and you'll get a host of links to the study mentioned in the Times of London over the weekend, the nut of which is this: the search you just tried released the equivalent of about 7 grams of carbon dioxide into the atmosphere.

However, not everyone (that is, almost no one in the tech world) appears to be buying the findings of Alex Wissner-Gross, an Environmental Fellow at Harvard University and the co-founder of CO2Stats, which lets websites track their carbon footprint.

Chief among the detractors is Google Senior vice president of operations Urs Hölzle, who wrote in the company's blog that a typical Google search requires far less energy, and therefore releases far less CO2 equivalent greenhouse gas than Wissner-Gross's figures.

Hölzle said each search amounts to 0.0003 kWh of energy per search, or 1 kJ, or "just about the same amount of energy that your body burns in ten seconds."

From the blog:

"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 of in the U.S.) produces as many greenhouse gases as a thousand Google searches."

Google is not the only one to question Wissner-Gross's findings, with the UK's The Register questioning his kettle calculations in typically acerbic fashion while TechCrunch compares the environmental costs of a search versus the cost of producing a single book - 2,500 grams, based on figures from publisher Penguin UK.

While it's hard to know what to make of Wissner-Gross's numbers - they have yet to be published - Google's figures are the first publication of their own estimates, giving us a chance to calculate the impact of all of those searches.

According to comScore, there were 7.784 billion Google searches conducted in November 2008 in the U.S. alone. At Google's calculation of 0.2 grams of CO2 equivalent greenhouse gas per search, that comes to 1.557 million kg of CO2 equivalent for the month, or about 18.7 million kg in a year.

Now, context: the U.S. in 2006 contributed 7,054.2 teragrams, or 7,054,200,000,000 kg, of CO2 Eq. greenhouse gases, according to the U.S. Environmental Protection Agency's latest figures.

I realize mixing 2006 and 2008 numbers leads to all sorts of fudging, but the point is this: Google searches would account for about two and half millionths of a per cent of emissions. That it something, but I suspect if you compare Google to the other top companies in the world, and think of all of those saved trips to libraries, it seems consumers probably shouldn't fret too much over the impact of all of those searches. But just in case, maybe consider adding a few more bookmarks to your browser.