While it may be pretty fundamental that computers need energy, being high-tech and green are not mutually exclusive, Philipson argues.

''IT is an important enabling technology. It helps people use energy more efficiently, it helps people design energy-efficient devices, it underpins so much of what we are talking about in a low-carbon economy,'' he says.

''Very few of the initiatives that are being talked about in terms of moving to a low-carbon economy are possible without the usage of IT as a key enabling technology.

''It's not a fad, this stuff. It's going to be a really big issue indefinitely.''

Computers and other information technologies are thought to account for about 2 per cent of the world's emissions, which Philipson says is roughly the same as the airline industry. The difference is most airline emissions are direct what is called ''scope one'' under the National Greenhouse Energy Reporting System while IT's emissions are indirect, or scope two.

While 2 per cent may seem small, finding efficiencies in computing can make a difference. Connection Research is among the organisations investigating ways to find efficiencies for the end user, in corporate IT usage, non-data centre IT, printing and the lifecycle of hardware.

With each of these areas, and subgroups, Philipson says there are techniques and technologies already available to reduce the demand for energy. The technologies range from the fairly obvious switching to low-watt PCs and more efficient flat screens, to virtualisation of servers in data centres. Techniques can include switching computers off and more complex ways of storing data efficiently and using it properly to save energy.

''In terms of life-cycle, the main thing to do there is to buy computers that have been made efficiently, that have less embedded energy in their manufacture, and many manufacturers are now disclosing that data, right through to the disposal,'' he says.

''In Germany, for example, a condition of purchase is that the manufacturer must take it back when you've finished with it. That's an example of a policy or a technique, and one assumes that they would dispose of it more efficiently than an end user would.''

Victoria has forged ahead with e-waste initiatives, ByteBack being a notable example, and at the weekend the ACT Government accepted used computers, laptops, monitors, printers, mobile phones and sundry for recycling. The Federal Government is considering taking such schemes nationwide.

Still, Philipson says finding efficiencies within the IT sector is marginal, and there is potential to have a greater impact.

''At the end of the day the consensus is IT is responsible for about 2 per cent of the world's carbon emissions, which is about the same as the airline industry,'' he says. ''That means that if you halved the electricity used by IT you'd make a 1per cent improvement. It all adds up but it's not a significant amount.''

Instead, attention is turning to how IT can make ''the other 98 per cent'' more efficient. These could come from smart electricity grids, better metering, finding efficiencies in manufacturing supply chains, developing newer, efficient technologies and ideas that have not even been thought of. ''That all adds up to, potentially, much, much more than the amount of energy that can be saved just by making the IT function greener.''