It takes a lot of energy to use a smartphone. You charge the phone daily, you browse and exchange messages, you create tweets and Instagram posts that are saved on some faraway energy-guzzling server. Yet the biggest way to lessen the environmental impact of your phone doesn't have anything to do with how you use it, according to a new review: All of that activity pales in comparison to how much energy it takes to extract and refine the dozens of precious metals that go into a smartphone. In other words, abstaining from replacing your smartphone more frequently than need be—and recycling it when you're done with it—may be the best way to make a difference.
"The current business model of mobile contracts encourages consumers to upgrade frequently, regardless of whether their current phone is fit for purpose," University of Surrey physicist James Suckling, one of the review's authors, said in a statement. "This isn't a trend that can continue if we are to have the mobile lifestyle we want, while still ensuring a sustainable future."
There are an estimated 85 million unused cell phones in the United Kingdom. Altogether, those phones contain almost four and a half tons of gold.
For the review, which will be published in the International Journal of Life Cycle Assessment, Suckling and his colleague Jacquetta Lee collected the results of dozens of studies about how much energy smartphones use and how much Earth-warming greenhouse gases their production emits. Suckling and Lee divided the studies into the different stages of a smartphone's "life cycle": Birth, productive life, and death. The researchers found the studies they reviewed to vary widely in their calculations of how much energy and greenhouse gas smartphones require, but the numbers the studies come up with generally agree within a factor of 10. Most of the studies also say that the most energy- and emissions-intensive phase of a smartphone's life is its creation. One way to think about this: There are an estimated 85 million unused cell phones in the United Kingdom, where Suckling and Lee are based. Altogether, those phones contain almost four and a half tons of gold, all of which took electricity to mine and purify.
Meanwhile, the review also found the vast majority of people don't recycle their unwanted smartphones. Instead, they keep their old phones, in case the new one breaks. (I admit I do the same—but have never actually had to re-use one of my old phones.)
In his statement, Suckling offered some ideas for reducing the waste and encouraging recycling. Service contracts could include "take-back" clauses that encourage people to send their old phones back to the manufacturer when they upgrade. Phones and their apps could also do more of their computing in the cloud, instead of on the device. If devices need to perform less processing, they'll require fewer precious metals to make; plus, they'll last longer. Whether service, phone, and app companies would be willing to make these changes without some benefit to them remains to be seen.
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