Just about everybody today knows what a hot mobile phone feels like in their hand.

That’s energy burning. And your hand is not the only thing your phone is making hotter.

The massive infrastructure that supports your phone is contributing to climate change, and the problem looks likely to get worse.

A recent report by sustainability analysis firm Greenspector found that popular apps TikTok, Facebook and Snapchat, with their billions of users, drive further energy use and emissions. Its research claimed that a person’s daily use of the world’s 10 most popular social media apps is similar to traveling 0.87 miles in a light vehicle, or 332 miles a year.

Lotfi Belkhir, associate professor of engineering at McMaster University, said our appetite for phones and the apps that populate them are a contributing factor to climate change.

“I think from a sustainability perspective, consumers need to know that much screen time on a smartphone is equivalent to digital pollution and digital waste,” Belkhir said.

“It's simply unhealthy in excessive amounts so I think the idea of digital pollution should start making its way towards the masses, that excessive and unnecessary use of smartphones can be just as bad as throwing away your plastic in the street.”

It is difficult to pin down just how many smartphones are out there. Forecasts from consumer data firm Statista show that there are almost 15 billion mobile devices in operation globally — that includes both smartphones and tablets.

Despite there being more devices in the world than people, consumers are still buying the latest and greatest models. This is pushed by a smartphone market that is fiercely competitive with major players like Apple, Samsung and Huawei, to name just a few, jostling for market share with the latest devices — with Apple recently unveiling the iPhone 13.

Consumer spending habits back this up. In its last quarterly earnings report, Apple reported $38.87 billion in iPhone sales — an increase of more than $12 billion the year prior. Samsung also reported a boost in sales in its latest quarterly report.

In 2018, Belkhir and his colleagues published a paper that examined the emissions trajectory of information and communication technology. Since that time, demand for digital services has only swelled.

Belkhir told CNBC that the cumulative use of millions of smartphones day to day is driving demand for bigger, more rigorous infrastructure to manage that load.

“If we didn't have the smartphones, we would not have all the data centers and therefore the indirect impact through the proliferation and rapid growth of the infrastructure is really what's creating this explosive increase in the carbon footprint of ICT,” Belkhir said.

Stefan Koester, a senior policy analyst at a thinktank called the Information Technology and Innovation Foundation, told CNBC that generally smartphone manufacturers have made their devices more efficient when it comes to electricity use but rapidly expanding connectivity, such as 5G, will put that to the test.

“Particularly during Covid, we all saw the benefits of increased access to telecommunications services, but 5G in particular will require larger energy draws,” Koester said.

Just what that impact will be on the emissions trajectory of digitalization remains to be seen, he added.

“I think it's a question that's not yet fully understood or answered. It could be either quite substantial or with the continued improvements in the power electronics  efficiency, it could be small.”

According to Ericsson, the uptake of 5G subscriptions has been much swifter than its predecessors. It estimates that there will be 580 million 5G subscriptions by year end. It predicts that by 2026, 5G networks will account for more than half of the world’s smartphone traffic.

Reducing emissions has been a banner issue for many of the tech giants with several making various pledges for the coming decades. iPhone maker Apple said it will be carbon neutral by 2030 and has invested heavily in renewable energy for its operations while China's Huawei recently announced it would be rolling out more energy efficient infrastructure like antennae to make its 5G networks greener.

Reducing emissions has been a banner issue for many of the tech giants with several making various pledges for the coming decades. iPhone maker Apple said it will be carbon neutral by 2030 and has invested heavily in renewable energy for its operations while China's Huawei recently announced it would be rolling out more energy efficient infrastructure like antennae to make its 5G networks greener. Snap has committed to being net negative by 2030.

Apple, Samsung, Huawei, Meta and TikTok were all contacted by CNBC but had not responded by the time of publication.

Data center energy hogs

While the model of the smartphone in your hand has become sleeker over the years, behind the scenes its supporting infrastructure has become more and more robust and sprawling.

That key piece of infrastructure is data centers, the vast halls of servers that store and churn through data every day, making every email, tweet and TikTok video possible.

Data centers and their insatiable hunger for energy have regularly come in for criticism, both in the role they play in climate change and the significant demands they put on electricity grids.

According to estimates from some researchers, these massive server halls collectively consume more than 200 terawatt-hours of electricity annually and growing. That’s about 1% of global electricity use. To put that in context, the state of New York uses about 226 terawatt-hours of electric power annually.

Despite all of that, John Dinsdale, chief analyst at Synergy Research Group, said there has been no slowdown in data center building, especially with large hyperscale data centers.

“We have consistently seen 60-70 new hyperscale data centers being opened each year and we expect a similar level of new data center openings over the next five years. At the same time data centers are growing in size so the hyperscale data center capacity is growing even more rapidly,” Dinsdale said.

He added that there is “a lot of greenwashing in marketing and PR material” around data centers’ commitments to using renewable or clean energy, but that it is factored into building and planning applications now more than ever.

For Belkhir, that transition isn’t happening fast enough.

“All the indicators are showing that this explosive growth is going to continue and with it the carbon footprint, unless we move very quickly to renewable energy across all of those layers of infrastructure like data centers and communication networks,” Belkhir said.

It is not just data centers that power our smartphones. The communications networks themselves, such as radio base stations, have grown to meet the demand of mobile devices, especially as more demanding uses like live video streaming and augmented reality become more common.

ITIF’s Koester said we’re still living in “primarily a fossil fuel world on the electric side” for powering these networks.

“There will be significant power draws as a result of building out these networks and the reliance on new devices. The hope is that by allowing for greater connectivity, allowing for faster processing that you will eventually get to a point where the benefits of these systems outweigh the inevitable draws,” Koester said.

“Of course, all this is relative to whatever the electricity grid backbone is and so hopefully we're living in a world in which the grid is getting cleaner and cleaner every year, and so hopefully the idea is this will be a sector that's fairly easy to decarbonize once we're able to decarbonize the grid in a significant way.”

Designed to fail?

Meanwhile, the entire manufacturing process behind each smartphone continues to be a carbon intensive endeavor, from the mining of rare earth metals, to the manufacturing and assembly of devices, to the shipping of products to shelves and mailboxes around the world.

“There’s a lot of embodied energy that goes into making these phones. There’s a large carbon and climate impact that goes into phone production and shipping new phones around the world,” Kerry Sheehan, policy director at repair website iFixit, said.

iFixit is a proponent of the right to repair. It carries out teardowns of electronic devices to see how they work and how resilient they are — or not — and makes the case for replaceable or easily repaired parts.

According to iFixit, a major factor in reducing the carbon emissions of smartphones is making them last longer.

Sheehan said the average lifecycle of a smartphone in the U.S. is 2½ years before someone moves on to the next model: “I haven't noticed a significant change over the last few years,” she said.

More often than not, she explained, people throw phones in a drawer at home or toss them in the thrash after they have upgraded to a new model. There is expected to be 57.4 million tons of e-waste created globally this year.

“Manufacturers are making decisions to glue in batteries and instead of using removable screws, making decisions to make batteries harder to access, making the phones themselves harder to open up,” Sheehan said.

“These are decisions that manufacturers are making in the design stage that have nothing to do with the technology of the battery itself, but they’re decisions that deliberately make repair much more difficult and make battery replacement much more difficult.”

This creates a situation where a consumer has little option but to replace an entire phone rather than replace a battery or a faulty part.

Her colleague Elizabeth Chamberlain, director of sustainability, said that the recycling of phones is a positive move that people can make when they’re finished with their devices, but its effects are limited.

“The majority of cell phone recycling is shredding and when phones are shredded over half of the materials in the phone have under half a recovery rate, so many of the metals in the phone are not recovered,” Chamberlain told CNBC.

With recycling only effective to a point, stretching out the lifespan of a phone is key, she said.

Chamberlain points to the French repairability index, a legal mandate in France introduced in January of this year that forces device makers to provide a score for consumers on how repairable the product is. It measures the ease of availability of spare parts or technical documents or whether the phone can be disassembled safely. The index is intended to advise consumers on how resilient a phone is before they buy it.

“As companies see that consumers are making choices based on whether or not batteries are user replaceable, they're more likely to make those changes,” Chamberlain said.

The French index is still new, so measuring its effects aren’t yet possible but Spain has drawn up plans to follow suit.

“The solution to this is keeping them longer, getting the full benefit of all of the costs that went into producing that phone by keeping them functional longer,” Sheehan added.

One of the companies at the vanguard of repairable sustainable phones is Dutch firm Fairphone.

It recently revealed its latest model, Fairphone 4, that uses repairable and replaceable parts. Monique Lempers, the company’s impact innovation director, explained that it is aiming to have a lifecycle of 4½ to five years.

“It’s definitely against the business case of selling as many smartphones as possible but that is also the behavior at the moment in the industry and that is causing e-waste,” Lempers said.

“There's a lot more that can be done on reuse. There's a lot more that can be done on refurbishment and the extraction of materials out of the phone is also still limited. Therefore it’s so important that we use the phone longer. Recycling is not the only solution or the most straightforward solution.”

Credits

Writer: Jonathan Keane
Editor: Matt Clinch
Design and code: Bryn Bache
Images and video: Getty Images