The internet's energy footprint is soaring by more than 10 per cent a year and now produces more greenhouse emissions than flying, according to a report in The Guardian.

There are now more than 1.5 billion people worldwide now connected to the internet, and a study commissioned by the US environmental protection agency suggested US data centres used 61 billion kilowatt hours of energy in 2006 - 1.5% of the entire electricity usage of the US.

And this figure is just the data centres - it does not include the energy you and I use to run our PCs to access the internet.

Like almost every other industry and nation when challenged on its carbon footprint, Google vice-president Urs Hölzle dismissed concerns about the environmental impact of internet use:

"One mile of driving completely dwarfs the cost of a search. Internet usage is part of our consumption, just like TV is, or driving. There is consumption there, but in the grand scheme of things I think it is not the problem."

However, the soaring electricity bill to run power-hungry servers in web data centres is causing internet companies to take the problem seriously. Extra energy costs do not necessarily bring extra advertising income, and this is hitting some bottom lines hard. And if a price on carbon is ever introduced, this will be even more significant. YouTube, for instance, which is owned by Google, could lose US$470 million this year. Google itself is pouring $2.3 billion into greater energy efficiency. And many Silicon Valley companies, such as Google andSun Microsystems, are investing heavily in renewable energy research ventures.

Read The Guardian article.