Though computers undoubtedly help us in our green endeavors, from finding ways of reusing our old stuff to telecommuting to reading up on green issues online, they are also a big culprit in both our excesses in energy use and toxic landfill pollution. The manufacturing of computers involves a number of dangerous chemicals, including mercury, lead, cadmium, and chromium, which have been linked to brain, kidney, and liver damage and cancers.
The computer manufacturing process is more energy-intensive than that of refrigerators, or even cars. A single 2 gram microchip creates 4 kilograms of carbon dioxide, and it takes more than 20 pounds of chemicals (not to mention gases, electricity, water, and other resources) to make a single sheet of them. Not only that, but those microchips are then packaged in a shell that may itself contain dangerous chemicals, and is derived from petroleum.
In Europe and elsewhere, newer, higher standards have been set and labels created to designate eco-friendly and safer computers. The US is lagging behind, but there are still several ways to get the most efficient and non-toxic computer possible. Energy Star ratings are a good place to begin, as they label computers with efficiency data. You can browse Energy Star-rated computers at http://www.energystar.gov (click on products, then computers). Another rating system to check out is the EPEAT--Electronic Product Environmental Assessment Tool--rating. Using a number of criteria, EPEAT grants computer models bronze, silver, and gold labels, all of which also meet Energy Star criteria. Some promising models that have taken steps in the environmental direction include a stylish, highly efficient Dell computer with a bamboo casing made with recycled materials and the Mac Mini and MacBook Air, which have mercury-free displays and come in less packaging than previous models.
If your computer is becoming obsolete or is broken, consider upgrading or repairing it rather than purchasing a new one. This may save you money, and will prevent the computer from ending up in the landfill, where it can leach its dangerous components into the soil. If you do decide to purchase a new computer, opt for a refurbished model rather than a new computer, as creating a computer takes 12 times the annual energy it will use once it is sold. Be sure that the company has a take-back or recycling program, whereby they will accept your computer once it becomes obsolete; the average life of a computer is only two years, and three-quarters of them end up in landfills. If your old computer is still in good shape, consider erasing all of your personal data and donating it to a school or charity. A few possibilites are listed at http://www.eiae.org/links/donation.cfm. If your computer is not in the proper condition for donation and your manufacturer does not offer a take-back program, look for a recycling progam, but be careful - some claim to recycle your PC only to send it to a Third-World country for disposal.
Opt for a laptop over a desktop, as laptops use up to 90% less energy. If buying a monitor, opt for an LCD/flat screen monitor, as these are more efficient than older, cathode ray tube (CRT) models. Additionally, laptop monitors and flat-screens do not contain the several pounds of lead found in their CRT brethren. If you need a device for printing, faxing, copying, or scanning, consider an all-in-one device rather than a number of individual ones, and remember that inkjet printers are up to 90% more efficient than their laser counterparts.
Though it has been claimed that it is easier on your computer to be left on, rather than turned on and off multiple times in one day, computers are built to handle thousands of on-off cycles. Enough, in fact, to turn your computer on and off 7 times a day for 8 years (4 times the life span of an average computer). So, if you'll be away from your computer for an hour or more, shut it down. Similarly, be sure to turn your computer off at night, or, better yet, plug your computer and peripherals into a power strip, and switch that off at night. This will not only save the electricity used to keep the computer on at night, but also the phantom load of power drawn even when the computer is off. The brightness of the screen or monitor is a big contributor to a computer's energy use, so check the brightness of your monitor and turn it down a bit. When you do leave your computer on, be sure to use sleep mode rather than a screensaver, as screensavers do not save energy. Sleep mode, on the other hand, can reduce energy usage by up to 70% and save you $30 a year when using it for the monitor, and $45 a year for the CPU/hard drive.