Hamburg
When people think of climate change, they usually focus on cars or factories. Yet a study commissioned by chipmaker AMD has shown that 14 large-scale power production plants must run worldwide just to provide electricity to computer centers.

Then there are millions of PCs in private or corporate settings to be figured in as well. Not to mention the manufacture and disposal of the machines, all of which damage the environment.

User behavior influences energy consumption. "That's why you should always activate the energy saver functions," recommends Mona Finder from Dena. This might turn the monitor off when the computer is not in use, for example. Animated screen savers are fossils from an earlier age of computing, she notes. "They just tend to use up energy, and they don't even save the screen."

It's difficult to put a firm number on how much energy, water, and raw materials go into PC manufacturing. It's been estimated that 15 kg of raw materials are needed for one processor, says Martin Hojsik from Greenpeace International in Bratislava, Slovakia.

It is clear, however, that valuable material is built into and around the PC: the metal casing in particular is of interest. "Metal is currently bringing in good prices," says Andreas Habel from the German Association for Secondary Raw Materials and Waste Disposal in Bonn. Some 1.87 million tonnes of electronic junk are produced each year in Germany, with IT scrap making up 114,000 of those tonnes.

The question of disposing old electronics is a tricky one. In some countries, the legal path is a clear one: old devices can be returned to the manufacturer free of charge or brought to community recycling centers. Yet this is still not a wonderful solution for the environment: even with the most modern of recycling technologies, a significant amount of material is sent to the landfills.

One important element for the environment is the reclamation of soft solder. The alloy is primarily used on the picture tube in monitors. In the past, monitors were simply put into landfills, leading to a situation in Habel's words where "40 percent of the lead contamination in landfills originates from old monitors."

Measured in terms of weight, 65 percent of each computer is brought back into the recycling chain. Yet one must also remember that the metal casing makes up most of a PC's weight. The recycling rate for metals in the electronic scrap pile amounts to more than 95 percent. Roughly 10 percent of the weight is used energetically, meaning that the material is burned.

Many manufacturers are seeking to lure customers with promises of computers produced in more environmentally friendly ways. Fujitsu-Siemens is offering a "Green PC," for example: "We've calculated that we require roughly 25 fewer sacks of coal to produce it than are needed for a traditional device," says marketing director Jorg Hartmann.

What can consumers do? Labels that stand for environmental friendliness also exist for PCs - perhaps too many, Hojsik finds: "I'm skeptical about how much these labels mean." 

It's instead better to ask about a computer's production, consumption and disposal procedures before buying it in the first place, he says. Because computers grow out of date quickly, it makes sense to look for machines that can be upgraded.