Check it out Google has turned the lights out and gone black, but it is only for today it seems. Apparently it is all in a good cause: Earth Hour which invites people around the world to switch off their lights for an hour during the course of Saturday 29th March. That hour is between 8pm and 9pm in whatever your local time zone is.

"Given our company's commitment to environmental awareness and energy efficiency, we strongly support the Earth Hour campaign, and have darkened our homepage today to help spread awareness of what we hope will be a highly successful global event" a Google spokesperson said.

If you have been reading my blog long enough, and paying attention, then you might recall my mentioning something very similar here last year when a Google custom search site launched a black version of Google called Blackle which is still up and running and claims to have saved 535,178.192 Watt hours as a result. As a result of the background of a black Google using less energy to display on a monitor than a white one that is. A theory that has been dismissed by those who point out that it makes no difference on an LCD monitor, which most of use today. Well, most of us in the developed world that is. When it comes to less fortunate, less developed, less well off nations the CRT still rules supreme.

So why isn't Google going black permanently? Because, according to a spokesperson "it saves no energy" for the reasons explained above. Indeed, last year Google stated that "our own analysis as well as that of others shows that making the Google homepage black will not reduce energy consumption. To the contrary, on flat-panel monitors (already estimated to be 75% of the market), displaying black may actually increase energy usage."

So perhaps you need to turn your lights off for a couple of hours instead, to make up the difference in carbon footprint terms for Google going black all day today then…