Most retired mobile phones are left in drawers instead of being recycled, according to a global survey conducted by Nokia.

A mere 3 percent of the 6,500 people interviewed for the survey recycled their mobile phones. Fortunately, only 4 percent end up in landfills, according to the survey. About 44 percent are simply stored at home. Many consumers also give phones to friends and family or just sell them.

A lack of awareness is the biggest challenge, according to Susan Allsopp, Nokia spokeswoman. Some 74 percent of consumers said they don't think about recycling their phones, and half aren't even aware that phones can be recycled.

"We were surprised by the low levels of awareness, but at the same time it's an opportunity for us to work with people to raise that number," Allsopp said.

To illustrate how an improved rate of recycling can affect the environment, Nokia said that if each of the 3 billion mobile phone owners recycled one, it would mean 240,000 tons of raw materials could be reused. The carbon emissions saved by reuse of that material would be the equivalent of taking 4 million cars off the road, Nokia said.

Between 65 to 80 percent of a mobile phone can be recycled. The metals from mobile phones can end up in copper roofs, ski bindings or dental fillings, and other materials are ground up into chips and used as construction materials or for building roads.

Nokia is expanding its infrastructure for handling used phones. So far it has collection points for mobile devices in 85 countries as well as partnerships with recycling plants on every continent, with the exception of Africa. Nokia doesn't profit due to the cost of building the infrastructure, according to Allsopp.

But there is another side: if Nokia can convince customers turn in their old phones to its collection points, it's a boon for the environment, but it also means phones won't be refurbished and sold again, prompting people to buy more phones.

The refurbishment of phones has turned into a big business, with a lot of money to be earned, according to Garter senior research analyst Annette Zimmermann. Nokia phones last a long time, and the phones are considered in India as the best refurbished ones, she said.

Allsopp has a different explanation why Nokia doesn't support refurbishment. "The governments of a number of countries do not allow the shipment of second-hand electronic goods to their shores, since they are concerned these will be unwanted and end up in waste piles," she said.