Dear Greta,

Never before has my mind been so restless as I imagine our society’s future. Humanity and our ecosystems are in the midst of profound changes. I had so many ‘aha’ moments in 2020. I realize that attempts to maintain a few people’s privileges destroy our civilization; and, on the other hand, I feel extraordinary hope that everyone on Earth can have enough food, proper shelter, and a meaningful, sustainable life. In this vision, we need wise choices for our health, environment, and technology.

This leads me to 5G, the fifth generation of wireless telecommunication networks. My research shows that 5G is a corporate scheme. It would impair efforts to create a sustainable society. The more I learn about 5G, the more I dream of another kind of Internet. Today I will describe how 5G use would harm our planet—and offer alternatives that would allow us to avoid it.

First, I want to tell a story of how a mobile Internet connection can take life and use energy. Then, I want to show you how to create more sustainable connectivity. The story stars a girl, a cat and a genie. (Geeks, watch out: I’ve got three hidden abbreviations here—with definitions named below1).

Last winter, Pash was a kitten, chasing squirrels on an icy porch. One day, Jack, Pash’s companion, captured her ice ballet on his phone and posted it on YouTube. Within hours, Pash was ranked most viewed kitten ever. Two weeks later, seven-and-a-half-year-old Altea sits in her dentist’s waiting room. To relax, this girl is watching cute cat videos on her mum’s smartphone. Meanwhile, NRgee, the genie, slumbers. NRgee can sleep for millions or even billions of years, curled up inside of tiny coal, gas or petroleum molecules. He can hide inside the even tinier nucleus of an atom, where there’s room for lots of genies. Superpowers give NRgee abilities to travel inside vehicles like water, wind, sun rays or batteries; to transform into other forms; to travel at the speed of light and to live eternally. Plenty of clones can assist NRgee when he wants to satisfy his master. Under specific conditions, we mortals can summon NRgee.

Actually, young Altea has the power to summon NRgee at her fingertips. Just by tapping the touchscreen, she can wake the genie! Freed from a molecule in the smartphone’s battery, NRgee transforms into electricity. In the blink of an eye, NRgee and his clones work all over the smartphone to get YouTube to stream Pash the Kitten onto Altea’s mother’s screen.

NRgee clones transform again, this time into microwaves from the smartphone’s antenna. They radiate in all directions around Altea. Only a minuscule fraction of the clones makes it to the cellular antenna. Most of the NRgee clones are lost. The lucky ones tell the cellular network that they need to reach YouTube’s data center as soon as possible, using an IP address. To deliver Altea’s order to stream the cute cat video to YouTube, NRgee seeks help from more clones traveling the electric power grid and feeding the Internet’s “highways.” To assist, most genies will first leave their long slumber (from coal, natural gas, uranium, you name it) using an incredible human-made machine called a power plant.

Whenever a molecule containing carbon frees a genie, a reaction makes him fart carbon dioxide (CO2). Power plants using fossil fuels (coal, gas, oil) or biomass use oxygen (O2) and emit CO2. So, these power plants do exactly the opposite of living plants. During photosynthesis, trees and flowers absorb CO2, emit O2 and capture NRgee from light to feed on it.

Back to Altea’s command: when it reaches YouTube’s data centre, other genies fly in, feed digital storage devices and servers, find Pash’s video and send it to Altea’s screen. Lots of NRgee genies are needed to carry the data-heavy video file and play the video for Altea before she goes to her dentist’s chair.

Greta, to show you where NRgee genies are most needed in this story, I’ve got a pie chart. This one shows that when you stream a video using 4G (available today), the mobile access network uses more energy (60%) than the smartphone (30%) or the data center (8%)2. The smartphone also uses significant energy to connect to the mobile network (3.7 times the microprocessor’s energy3). The mobile network is composed of many parts and each consumes energy to operate4,5.


Compared to all data shared or accessed using a mobile connection (for video, music, photos, websites, documents, posts, tweets, emails, texts, Apps, etc.), video consumes the most data (63% and growing6) and the most energy. Video emits the most greenhouse gases and has the greatest impact on climate change. Then, although 5G is more energy-efficient than 4G, it will cause a dramatic increase in energy use and greenhouse gas emissions since it requires additional infrastructure and will increase data traffic. In 5G’s era, video is expected to have a far greater footprint than it already has. (When I talk about video, I mean streaming, video-calling and messaging.)

I’ve got to admit that I love watching videos on a smartphone, tablet or laptop. But my priority is to reduce my carbon footprint. When I learned how much energy is involved in watching videos, I had to question my habit. Is it possible to reduce videos’ energy demands and environmental impacts—and still watch them?

It is possible! The key to a more sustainable Internet is to limit the use of energy-guzzling mobile networks and rely on wired networks whenever possible.

If you love watching videos while traveling, load them onto your device using a fixed Internet connection (wired is better; wireless is possible), or a public Wi-Fi hotspot. Plenty of movies will fit on a smartphone or a cheap memory card. (A microSD card can fit hundreds of hours of high-definition video). If you pay monthly for a video streaming service, you should have a download button in the App. Some platforms offer downloads free of charge. Downloading one hour of video takes from a few seconds with an optical fiber connection, up to a few minutes with a decent 10 megabits per second (Mbps) wired connection.

With pre-loaded videos, you won’t experience drops in mobile service, even in tunnels or rural areas. You will save your battery since your device will not have to radiate radio frequencies to the nearest mobile (or Wi-Fi) antenna while your video plays. Your body will be less exposed to electromagnetic radiation. Then, by not using a mobile network (the largest, blue, slice of the pie chart), you will reduce energy use significantly. If it’s alright to be offline for a while and you want to save even more energy and radiation, switch off mobile data and Wi-Fi. Activate plane mode whenever possible. The same benefits apply to music downloads, although music uses less data than video.

If you really need to load a video while you’re on the go, first try connecting to a Wi-Fi hotspot, which uses less energy than a mobile network7,8. If possible, download the video and, when done, switch off the Wi-Fi—and enjoy your video. If a hotspot is not available, your last option is a mobile connection. If you decrease the video’s quality, you’ll save energy: open video quality settings by tapping three little dots, three small horizontal bars, or a cogwheel. For example, on YouTube, 360p will use significantly less data and energy than 720p. In Netflix’s App, opt for “mobile data usage” then “save data.”

If you love long video-calls on your mobile device, first try connecting with a cable. I didn’t think I could do it. But there are elegant wired solutions for mobile devices9. I’ve switched off our home Wi-Fi, and all family members use superfast cable connections. We’ve all reduced our mobile and energy use. If you really must have mobility, choose Wi-Fi over mobile data. If you really need a mobile network, look for a setting like Google Duo’s “limit mobile data usage.” This could mean upgrading to a newer version of the mobile video App. After upgrading, look for new features that can save data and energy.

Besides reducing energy use and climate impacts, keeping distance from wireless devices is healthier. A Wi-Fi router can be switched off easily at night using a mechanical outlet timer.

Another thing, if you care about reducing your carbon footprint: avoid Fixed-Wireless-Access (FWA) connections. FWA uses inefficient mobile networks, and typically much more data than a mobile device connection. Unless there’s no alternative, it makes little sense for users or the environment. If fiber optics or other wired links are available (TV cable, VDSL, ADSL10), they will provide the best experience in reliability, speed, response time, security and energy efficiency.

Video will continue to drive data traffic—and the Internet’s energy consumption and greenhouse gas emissions. In an article about the economic implications of 5G for network operators, William Webb summarizes the industry’s most promising 5G applications. He shows that there is no proof that autonomous cars, virtual reality, the Internet of Things (IoT), industrial IoT, network slicing, remote surgery or smart homes can benefit from national 5G networks.

Why are simple guidelines about reducing our Internet footprint not taught in schools or described in user manuals? Why do we learn to turn off lights and use energy-saving bulbs, to turn off the tap and use eco-shower heads, but not to switch off the Internet connection when we don’t use it, and limit 4G/5G connections? Does this knowledge compromise the industry’s dream of ever-exponential growth in mobile data and 5G?

If significant numbers of people adopted the steps I reported here to reduce mobile video streaming and calls, we would significantly reduce our energy use and greenhouse gas emissions. Mobile traffic could decrease! This leads to the crazy idea (is it?) that we could avoid 4G network saturation—as well as large-scale 5G network deployments. Let’s leave 5G to its true beneficiaries—a few large factories. By deploying infrastructure at specific sites, we would not have to build or operate 5G networks. We’d save energy and reduce greenhouse gas emissions dramatically. This is my dream.



1 Hidden abbreviations - answers: Kitten: Pash - HSPA 3.5G (High Speed Packet Access); Girl: Altea - a-LTE-A - LTE-A 4.5G (Long Term Evolution-Advanced); Genie: NRgy - NR 5G (New Radio).
2 Yan M. et al., Modeling the Total Energy Consumption of Mobile Network Services and Applications, 2019, fig. 5.(b) (Video Play) – using 4G macrocells.
3 Ibid., table 1. To stream a video (“video play” scenario), on average, 51.4 J are consumed by the 4G network, while 13.8 J are consumed by the CPU (video play).
4 In mobile networks, operating energy is consumed mostly in base stations (est. 80%), but also in backhaul connections (between base stations and the mobile core network) and in the mobile core network.
5 A base station’s operating energy includes (in decreasing order): power amplifiers, transceivers, power supplies, cooling, and others. Humar I. et al., Rethinking Energy Efficiency Models of Cellular Networks with Embodied Energy, 2011, fig. 3.
6 Ericsson Mobility Report June 2020.
7 On a smartphone, 4G consumes 23 times more energy than WiFi.
8 Mobile networks (in 2015, 5G not yet included) caused about 60% of total carbon emissions of all telecommunication networks. Mobile networks: 100 Mt CO2e ; total all networks : 169 Mt CO2e. Malmodin J. & Lundén D., The Energy and Carbon Footprint of the Global ICT and E&M Sectors 2010–2015, 2018, fig.6.
9 You need up to three things to connect your smartphone, tablet or laptop with a cable. First, you need an ethernet RJ45 adapter for your device (unless your laptop has an RJ45 socket, or you already have an RJ45 adapter). Examples here. Then, you need an ethernet cable. See examples here: or retractable cables here. Last, if your device is too far from your Internet router, you can use a pair of power socket adapters anywhere in your home. Plug one adapter near your device, and the second adapter near the router, connected with a second ethernet cable). See here. Powerline adapters are a higher investment, but they make it possible to switch off your Wi-Fi. My family uses many of these adapters around the house.
10 VDSL2 and ADSL2 speeds over 10 Mbps require a distance from the exchange no longer than 2.7 km (1.7 miles).