With so many computers in the world today – it’s estimated that there’ll be two billion in use, worldwide, by 2015 – one of the most important things we can do to reduce our impact on the environment is to buy and dispose of them wisely.

From cradle …
The first step towards reducing your computer’s carbon footprint is to buy one that takes into account the environmental impact of its entire “life cycle” – from cradle to grave. Greenpeace’s Guide to Greener Electronics regularly rates the top 16 manufacturers of computers and other electronics. The guide’s top five computer brands right now are Wipro (Indian electronics company), followed by HP, Acer, Dell and Apple.

There’s also EPEAT (Environmental Product Environmental Assessment Tool), which rates an assortment of products, including computers, as gold, silver or bronze, based on their environmental efficiency. Gold laptops (called “notebooks” on the EPEAT website) are longer-lasting, less toxic (e.g. no added cadmium, mercury or lead), more energy-efficient and easier to recycle than bronze or silver products.

EPEAT is based in Portland, Oregon (in the US) but lists more than 3600 products from 41 countries. And there’s plenty of choice. In the US, for instance, 805 (80 per cent) of the 996 laptops listed are certified gold.

It’s also a good idea to buy hardware appropriate to your needs. Faster processors and larger monitors might sound impressive but if you don’t need them they’ll only end up costing you more (to run) and have a bigger environmental footprint.

To grave …
The United Nations estimates that between 20 and 50 million tonnes of e-waste is generated worldwide every year – and that figure is expected to grow as the lifespan of computers decreases (we kept our computers for 4-6 years in 1997 and for only two years in 2005). And according to the US Environmental Protection Agency, Americans get rid of 47.4 million computers (as well as 27.2 million televisions and 141 million mobile devices) a year.

What to do with them all? They can’t just go out with the household garbage, for two reasons: computers contain up to 1,000 substances, many of them toxic, which can leach into the environment, contaminating the surrounding air, water and soil; and, more cheerfully, many of their components can be reused.

So when it’s time to part with your old laptop, there are three main options:

1. Donate it: Donate a PC is a free service in the UK that lets you list an unwanted computer that a charity might be able to use; it also explains how to remove (not just delete) data from your old computer before donating it. Give Now lists charities in Australia that need used computers. Green PC, also in Australia, upgrades second-hand computers donated by governments and corporations, then sells them (internet-ready and with software installed) at a discount to low-income families, people living with disabilities and community organisations.

2. Recycle it: Most countries have programs to help you recycle your old computer. In Australia, for instance, there’s the National Television and Computer Recycling Scheme and Techcollect (funded by 60 technology companies) which list drop-off locations for used electronics. Some local councils have twice yearly e-waste collections.

3. Return it to the manufacturer: Many companies have recycling or take-back schemes (and are legally required to in some countries). Some take back only their own computers, others such as Apple, Dell, Sony and Acer accept computers of any kind.

The end of the line – or is it?
What happens to computers after they’re collected? In an ideal world, they’re taken apart so that some of their components can be reused and the rest made into other products. Exactly where this recycling happens, however, is a contentious issue.

For decades, developed countries shipped their e-waste to developing countries, where people (often children) would physically dismantle our old computers, putting themselves and their environment at risk.

The Basel Convention, a 1992 treaty designed to reduce the movement of hazardous waste and signed by 180 countries, went some way to reducing this practice. Many countries, and companies (Dell was the first, in 2009), have now banned the export of e-waste to developing countries. But as recently as last year, the Basel Action Network found that up to 80 per cent of e-waste collected in the US is still exported to India, China and Pakistan.

To cradle …
The latest way approach the problem of e-waste is the “cradle to cradle” way. The term was coined by architect William McDonough and chemist Dr Michael Braungart, who run a global sustainability consulting firm in the US and wrote Cradle to Cradle: Remaking the Way We Make Things in 2002.

The key is “ecologically intelligent” design, they say, inspired by the circularity of nature’s ecosystems. That is, products are designed to be made into new products at the end of their “lives”.

Apple’s entire range of products, for instance, is free of toxic materials including lead, mercury, arsenic and PVC – to ensure that there’s less thrown away, fewer harmful substances and more bits recycled, which in turn takes pressure off resources required to make new products. And more and more manufacturers are following suit, keeping the end-game in sight when creating their products – it makes economic as well as environmental sense, after all.

Written by Louise Southerden, an award-winning travel writer, author and eco-blogger based in Sydney, Australia. Follow her on Twitter, like her on Facebook and read more of her work at No Impact Girl.