In the UK, The Independent newspaper has reported that:

One in five white-collar workers told a national survey that they left their computers on at least three times a week, wasting more than £100m of electricity every year.

According to the PC Energy Report, power stations generating the electricity emit 200,000 tonnes of carbon a year - equivalent to the exhaust fumes of 120,000 4x4 cars. Switching off would save as much pollution as from all the cars in a city the size of Liverpool.

Shockin, eh? But think about it - how many times have you walked through a business precinct on a dark evening. There's no one left inside the hives of glass, concrete and seel except security personnel and workaholics. Entire floors are ablaze with light and screen "savers". Absolutely unnecessary. I know there's a rumour floating around for years - that the effect of starting up your PC in the morning used more energy than leaving it on overnight - an argument I could never see the logic of.

So, people, let's shut down those PCs...

The PC Energy Report »

The Independent: Office workers who leave computers on all night 'add to global warming' »

Greenpeace UK blog on climate change at the 2006 Labour conference.