7 of the Most Eco-Friendly Cell Phones on the Market

Cell phones are now in the hands of more than half the world's population and these days they are far more than just a way to make calls. They're a mighty tool for environmentalism, they can bring us closer to wildlife, and they perform so many functions that we've come to rely on.

But yes, a cell phone is also an electronic gadget that requires fossil fuels and some amount of hazardous materials to create, so when looking for a new cell phone, it's always good to keep the planet in mind too. By 2017, it's estimated that 400 million green cell phones, or those made with at least 50 percent recycled content, will be shipped and Sprint announced this year that it will begin requiring all cell phones that it sells to meet standards set by UL Environment, which measure environmentally sensitive materials, energy management, manufacturing and operations, impact to health and environment, product performance, packaging and product stewardship.

Even with all of this progress, the market still isn't full of green cell phone models, so if you're looking to upgrade, here is a list of the most eco-friendly cell phones out there right now to make your buying decisions easier.

1. Anything Used

E-waste is a huge problem. It's estimated that the over 140 million cell phone users in the U.S. upgrade their phone every 14 to 18 months. That equals a heaping pile of hardly-used cell phones out there that could have a few more years of useful life before being recycled. So really, the greenest cell phone you can buy is a used one.

Ebay and Craigslist are good places to look, and almost all cellular companies, plus retailers like Best Buy offer certified refurbished phones, so you can score a like-new phone at a much cheaper price and do a good deed for the planet by extending the life of the product and keeping toxic e-waste out of the landfill.

2. iPhone

The iPhone, along with other smartphones, makes it to this list because of the amazing multi-functionality of the device. Think about it: the iPhone is your cell phone, iPod, digital camera, electronic planner, e-reader, GPS device, calculator and so, so much more. In fact, the more uses you find for your smartphone, the more environmentally-friendly it becomes because each time you consolidate your gadget needs into the apps and functions contained on your smartphone, the fewer peripheral devices you need. The fewer electronics you buy, the lighter impact you have on the planet.

3. Samsung Galaxy Exhilarate

Samsung has pretty much been the king of green cell phones, coming out with new models each year. The Galaxy Exhilarate is an Android smartphone that is made with 80 percent post-consumer waste material and comes with a more efficient charger. It debuted at CES this year and went on sale in June through AT&T.; The phone gets green points for being mostly made of recycled materials and because, as an Android phone, it can take the place of so many other gadgets like the iPhone listed above. Also the $30 price point makes it more accessible to more people, which is key for adoption of these greener models.

It's Platinum Certified by UL Environment and the first phone to be a part of AT&T;'s eco-rating system that it just launched this summer.

4. Samsung Replenish

Similar to the Galaxy Exhilarate, the Samsung Replenish is an Android smartphone sold through Sprint that got Platinum Certification from UL Environment. It features 82 percent recyclable materials and 34 percent recycled plastic housing, while eschewing PVC, pthlalates and brominated flame retardants.

5. Samsung Evergreen

The Evergreen is made from 70 percent post-consumer recycled plastics and the packaging is 80 percent post-consumer recycled paper. The phone received Platinum Certification from UL Environment and also features an Energy Star efficient charger that notifies you when the phone is done charging. It has a full QWERTY keyboard, camera, web browsing, apps and tons of other features.

6. Micromax's X259

The Micromax is a solar-powered cell phone that is actually affordable and that you can buy now. It features a 2.4" color screen, a camera, Bluetooth connectivity, radio capability, and a dual SIM setup. Three hours of sun gives users 90 minutes of talk time, which is great for those in developing nations where electricity is not always accessible and also for those who would rather fuel their conversations by the sun.

7. The Phone You Have

Do you really need to upgrade your cell phone? With all of the shiny new smartphones coming out every year, it's hard to resist moving to a new model, but it's likely that the one you're using right now accomplishes all of the things you need and more. Still have the iPhone 3G? The difference between that and the 4S is pretty minimal. One of the best things we can do to protect the planet is to use all of our things for longer and then to dispose of them in the most responsible manner at the end of their lives.

What to Do With Your Old Phone

If your phone is broken or you're just really ready for an upgrade, recycling your old phone is easy and can also make you anywhere from a few extra dollars to a few hundred. Companies like TechForward, NextWorth, Gazelle and ReCellular all pay cash for used cell phones. They refurbish the phones and resell them and those that can't be resold are recycled. Most cellular companies are now buying back old phones too.