Our green credentials are always in the spotlight. Whether its reducing our airmiles by cutting out our UK vacation or eating less meat - there are always options to improve our green-ness. One of these is the choice of mobile phone that we own.

Retaining the smartphone you already own is your greenest option. First, we point to hazards faced by extractive and factory workers who make these devices for us. Their workplace pressures intensify each time consumers order the latest model smartphone. By keeping smartphones for as long as possible, users can de-pressurize the labor process.

Second, we look at smartphones among an array of digital screen technologies that use sizeable amounts of energy and natural resources, both in their production, through the emission of greenhouse gases and hazardous pollutants, and in their useful lifetimes, because of their need for what is often coal-fired power to recharge and connect to network systems and data services.

If we combine emissions from manufacturing and the electricity that powers network and data-storage facilities, smartphones and other so-called terminal platforms produce about 1.4 percent of the world’s total carbon footprint. Most of that happens during manufacturing; over the useful lifetime of a phone, relatively few greenhouse-gas emissions are produced. Extending that life by keeping them longer makes them greener.

Otherwise, they become poisonous waste. According to the United Nations University (UNU), “Electronic waste, or e-waste, refers to all items of electrical and electronic equipment and its parts that have been discarded by its owner as waste without the intent of reuse.”8 When we throw smartphones away or “recycle” them, they frequently end up as toxic e-waste, the fastest-growing element in global waste streams: about 46 to 50 million metric tons, and growing by three to four percent annually. Cellphones alone comprise approximately ten percent of those figures. The average period people in the global North keep their phones is less than two years. This is out of habit, not loss of functionality. Retaining them for as long as possible can lighten the flow of e-waste to an already overburdened system.