Leading article: Big turn off

It's tempting, we admit. The screensaver is gently meandering over the darkened screen. You're exhausted and in a hurry to get back to watch EastEnders. So why bother to turn the office computer off when you leave work? Well, as it happens, there is an extremely good reason.

Computers left on standby cost Britain some £123m in energy bills every year. The machine may look inert as you slink away, but unless it's turned off, your computer is actually sucking in electricity - all through the night. Think of all those tonnes of harmful fossil fuels being incinerated to generate the electricity to needlessly run your PC at 2am.

And we know that you do. Some 78 per cent of British employees claim to be more environmentally conscious than they were five years ago. But a third of you still leave your computers on standby. It's not just computers, of course. One million tonnes of carbon are pumped into the atmosphere each year as a result of televisions, DVDs and other household electrical appliances being left on standby.

Of course, we suspect some innovations would encourage us to switch off. How about computers that take less time to boot up, for example? And if some offices turned their lights out in the evening, rather than allowing them to blaze away all night, might employees be more inclined to conserve energy, too?

But, ultimately, there can be no excuses. We must all do our bit to preserve the environment. So remind your colleague next time they absentmindedly head for the door after a busy day that they can help save the planet with just the click of a mouse.