Dr Gerald Weber is a computer scientist, but you might not think it by looking at the phone he uses.
It's a Samsung Galaxy S II which, while not yet in retro territory, has been succeeded by 16 newer models in the five years since it hit the market.
For the Auckland University researcher, it does the job: it has a great screen, brilliant colours and works fine for texting, taking notes and shooting pictures and video.
Weber doesn't feel the need to splurge $1400 on a new iPhone6s and he couldn't care less about not having 3DTouch, Peek and Pop or a 5.5-inch display.
"Already for years now, our mobile phones are so powerful that they can meet all our necessary demands."
Where he does face problems is the fact that support for social media and web browsing on his phone has all but vanished, as the app markets don't cater for its older hardware.
"From time to time I want to check my email, but that, too, has stopped working."
Trying to install new operating system versions on the phone would kill it.
Still, he has no plans to upgrade and add his old Galaxy to an ever-growing mountain of global electronic waste, or e-waste.
"I think that it's important that we do not push each other to throw these things away without good reason."
Weber believes what's called engineered obsolescence - companies deliberately planning for products to become no longer usable or fashionable so consumers are pushed to buy new ones - poses a threat to environmental sustainability.
"Right now, we're all under pressure to upgrade, and that's a problem."
Technology commentator Peter Griffin described engineered obsolescence as a "sustainability nightmare" that wouldn't go away any time soon, given that the tech sector had built the strategy into its technology roadmap and business model.
Apple, for example, had introduced a subscription plan that promised a new iPhone every year, reducing even further the amount of time the smartphone maker expected its customers to hold on to an iPhone.
There had been some efforts to come up with modular phones like the Fairphone, where components like the battery, processor and flash memory could be upgraded with the handset chassis remaining.
But few were yet on the market and the sleek, all-in-one design of the iPhone and Samsung Galaxy suggested the prevailing wisdom was to prevent phone users from going "under the hood" of their devices altogether, Griffin said.
"It would be okay if there was a well-defined and understood recycling programme that saw the materials used in these phones going back into the supply chain.
"But many of them are likely to hang around in people's cupboards or end up in landfill."
E-waste was a particular issue in New Zealand, which had no legislation to manage electronic recycling, meaning potentially valuable and environmentally harmful resources like copper, gold and metal were being taken to the dump each day.
According to a new report in the journal Nature, the amount of electronic waste produced by the world, such as phones, televisions and appliances, doubled to 42 million tonnes every year between 2009 and 2014.
Weber felt much of this could be avoided if consumers fought the urge to upgrade and learned to love their current gadgets.
"Just like you wouldn't throw away a pair of blue jeans you really love, we should all be encouraged to appreciate our devices."
How to make your phone last longer: Gerald Weber's tips
1. Be selective with updates: you do not always need the newest Android. Updates might slow down your phone.
2. Encourage your friends to move to open alternatives of social networks; it's a better protection against forced updates, and all of you have more control.
3. Turn off Wi-Fi and packet data if not needed: energy use, heat and frequent charging may wear out batteries.
4. Keep it dry: when sailing or tramping, at least have it in a zip bag if it's not waterproof. You can operate most phones through the bag.
5. Consult the web for advice and consider alternative operating systems such as CyanogenMod if you can't update your phone any more or it gets too slow.
Dr Gerald Weber will be speaking alongside Auckland University colleagues Dr Cate Macinnis-Ng and Professor Paul Kilmartin, and Auckland Council waste planning manager Parul Sood, in a free public talk on waste minimisation on Thursday, August 18. The lecture will be held from 6pm in lecture theatre 1, of Auckland University's Building 303, 38 Princes St.