Calculating The Carbon Footprint Of A Google Search

That’s exactly what several scientists and researchers tried to do: figure out how much CO2 is emitted from performing a search on Google. Here’s what the Times Online said over the weekend in summarizing these estimates:

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, according to new research.

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.”

The issue is how much energy is used by Google’s data centers, which process search queries from all over the globe. There’s another estimate in the piece, which is more favorable for Google:

A separate estimate from John Buckley, managing director of carbonfootprint.com, a British environmental consultancy, puts the CO2 emissions of a Google search at between 1g and 10g, depending on whether you have to start your PC or not. Simply running a PC generates between 40g and 80g per hour, he says. of CO2 Chris Goodall, author of Ten Technologies to Save the Planet, estimates the carbon emissions of a Google search at 7g to 10g (assuming 15 minutes’ computer use).

The same day Google posted what appears to be a refutation/response on its blog:

Recently, though, others have used much higher estimates, claiming that a typical search uses “half the energy as boiling a kettle of water” and produces 7 grams of CO2. We thought it would be helpful to explain why this 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 of in the U.S.) produces as many greenhouse gases as a thousand Google searches.

In one sense, there’s an absurdity to this discussion because one could argue that the internet saves paper and thus trees, which reduce CO2 in the atmosphere. One could also argue that the internet permits people to work from distributed locations and so they don’t need to commute as much, which in turn saves fossil fuels and CO2 emissions. The nature of the debate and the conclusions drawn depend heavily on the lens though which you view the question — and how wide the aperture is.

Biofuels were initially aggressively embraced by the EU until it was discovered that food cultivation was threatened in some areas, as well as the rainforests.

The question of environmental impact is thus a complex one. This is not to say that data centers can’t become more energy efficient and they will. Whatever your opinion of Google it’s clearly one of the most “responsible” companies in Silicon Valley in terms of environmental work and advocacy.