Over a wire is the most energy efficient way to transfer data. In a Digital Waste survey, when we asked people if they tried to transfer data (particularly large quantities of data) using wired cable instead of using Wi-Fi, or 3G, 4G or 5G, 62% said no.

A German study found that video streaming for one hour:
• Using a fiber optic cable caused 2 grams of CO2
• Using a copper cable caused 4 grams of CO2
• Using a 3G network caused 90 grams of CO2.

Some studies indicate that transferring data over 5G can be 90% more energy efficient than 4G. However, other studies state that 5G base stations will require at least twice the amount of energy to run as 4G stations, and that these costs can be even higher depending on the type of processing that occurs. Because of its need for speed, 5G will require “dozens of times more” base stations than 4G, adding to the overall energy bill. Other studies estimate that 5G will drive a 160% increase in overall energy consumption over 10 years because so much more data will be sent using 5G. Indications from China, which has amongst the most advanced 5G rollout, are that energy costs are higher than expected, with some carriers looking for government subsidies.

Let’s assume for a moment that sending one gigabyte of data over 5G will be more efficient than sending it over 4G. This will not cause the overall data energy costs to go down because there will be an explosion in the amount of data sent. And it’s hard to imagine how 5G could ever be more energy efficient than fiber optic cable.

What is this thing called progress? Progress in consumption? Progress in the extraction of raw materials? Progress in destruction of the conditions for life on this planet?

If you make a phone call for one hour using one of those ancient phones connected to a landline, about 3.5 MB of data will be produced. If you make the exact same audio call using Skype or Zoom, about 27 MB will be produced. Is that progress? “Wow,” a technologist said to me when I showed him these figures, “you should have seen what it used to be like making a call over the Internet. It’s got much more efficient.” He said it with pride in his voice. As if in 2021, creating 10 times more pollution to make an audio call with your new technology that replaced an “old” technology was something to be proud of.

One of the defining characteristics of most modern-day technologists and developers is their almost total lack of concern—if not disdain—for energy-conscious thinking. They treat digital as this limitless, boundless, costless space. I heard one developer sneer about how he “wasn’t going to lose any sleep” over whether his app was wasting energy or not.

How do we change this horrible, destructive culture that has led us into this climate emergency? One practical step is to focus on conserving energy. If you’re transferring data:
• Wired is better.
• Wi-Fi is about twice as inefficient as wired.
• 3G, 4G, 5G are the diesel trucks of data transfer.

German study highlights carbon footprint of video streaming
Study: 5G Has 90% Better Energy Efficiency Than 4G
5G base stations use a lot more energy than 4G base stations: MTN
5G will prompt energy consumption to grow by staggering 160% in 10 years
The 5G Dilemma: More Base Stations, More Antennas—Less Energy? - IEEE Spectrum
5G Base Station Deployments; Open-RAN Competition & HUGE 5G BS Power Problem