A United Nations study, due to be published later today, has found that around 1.8 tons of raw material are required to manufacture the average desktop PC and monitor, and that extending a machine's operational life through re-use holds a much greater potential for energy saving than recycling.
The study claimed the manufacturing of one desktop computer and 17-inch CRT monitor requires at least 240kg of fossil fuels, 22kg of chemicals and 1,500kg of water. In terms of weight, the total amount of materials used is about equal to that of a mid-sized car.
By far the best way to minimise impact on the environment from a PC is to extend its useful life, said Eric Williams, a researcher at the United Nations University in Tokyo and one of the report's co-authors.
Users should think carefully about whether they really need a new computer, if upgrading their existing computer could serve the same purpose. Actions such as delaying replacement and upgrading the memory or storage space or, if the machine is replaced, donating the old computer so that it may continue to be used, offer potential energy savings of between five and 20 times those gained by recycling.
This is because so much of the energy required to manufacture a PC is used to make high-tech components such as semiconductors. Those components are destroyed during recycling to collect a small amount of raw materials.
In an earlier study published in late 2002, Williams concluded that 1.7kg of fossil fuels and chemicals and 32kg of water are used to produce a single 2g 32Mbyte DRam memory chip.
Seemingly endless advances in technology are encouraging people to replace their machines and falling prices are making replacement a more attractive option that upgrading and have users accustomed to a two-year to three-year upgrade cycle.
However, there are some encouraging signs. In the corporate market machines supplied under service contracts often have a good chance of being reused thanks to programmes offered by equipment suppliers such as Dell.
Dell has seen a tremendous increase in the number of machines it receives from customers for processing before either recycling or donation to agencies, said Tod Arbogast, senior manager of asset recovery services at Dell.
The company has handled millions of machines since 1992 when it started offering its asset recovery service, which costs around $25 per machine and includes collection, transportation and reporting and, for PCs, destruction of data on the hard-disc drive. The service is available in the US, Europe and select countries in Asia and Latin America.
Around two fifths of Dell's commercial customers participate.
"We believe no computer should go to waste," said Arbogast. "The ultimate solution is to reuse the computer either as a donation, for parts or on the second-hand market."
The market for used computer equipment on eBay was around $2bn in 2001, said Williams.
Williams suggested that private and corporate users should do something with their old machines quickly.
"The longer it sits in your closet or desk, the less value it will be to you and whoever will be getting it."
The report also looks at energy use and says always-on networks are making the US Department of Energy's Energy Star programme less relevant.
"I think it needs to be renewed," said Williams.
Too many computers at companies are prevented from entering their standby mode by Lan traffic, which keeps them awake and consuming power even while they are not in use. While acknowledging that some machines are kept online to allow network maintenance to take place, Williams suggested redesigning network cards to allow the PC to go to sleep and then wake it should there be any important network traffic.
Non-residential office and telecommunications equipment consumed around 3% of all electricity supplied in the US in 2000, according to a January 2002 study from the US Department of Energy. Of that, around 40% was consumed by PCs and associated monitors.
The report, "Computers and the Environment: Understanding and Managing their Impacts," is published by Kluwer Academic Publishers and the UNU and is available in paperback (ISBN: 1-4020-1680-8) or hard cover (ISBN: 1-4020-1679-4) editions and costs $35 and $83 respectively. The UNU's website for IT and the environment is http://www.it-environment.org .
Martyn Williams writes for IDG News Service