The Carbon Footprint of Streaming Movies and Videos

HD-quality video streaming produces different levels of greenhouse gas emissions depending on the transmission technology. Greenhouse gas emissions can be reduced considerably, depending on the data transmission technology used.

The COVID Pandemic with the lockdowns, and the rise of the home office culture, with live video webinars, conference calls, and binge watching movies and TV shows has led to a very high traffic in the digital autobahn. This definitely has an impact on the climate and carbon emissions can vary, as past studies showed. Now a German government funded study has found how our usage of HD Streaming, usage of cell phones and television sets and which transmission technology we use influence carbon emissions.

Which transmission technology is best for reducing green house gas

Greenhouse gas emissions can be reduced considerably, depending on the data transmission technology used. This is shown by initial research findings commissioned by the German Federal Environment Agency.

A copper cable (VDSL) generates 4 grams per hour. UMTS data transmission (3G), however, produces 90 grams of CO₂ per hour. If the transmission technology used to transmit data is 5G instead, only about 5 grams of CO₂ are emitted per hour. The electricity used by the end device is not factored into this calculation.

The CO₂ emissions generated by data processing in a data centre are relatively low, at 1.5 grams of CO₂ per hour. However, the technology used to transmit data from the data centre to the user determines the climate compatibility of cloud services like video streaming.

German Environment Minister Schulze said: “To date, the data available on how digital infrastructure affects the climate has been extremely sparse. This is why we are working to bridge the existing gaps in our knowledge with solid research. After all, good policy needs to be based on good data.

These findings now show that it is possible to stream data without negatively impacting the climate if one chooses the right method for data transmission. From an environmental perspective, it would be a good idea to set up more public WiFi hotspots, as this is more climate-friendly than streaming in mobile networks. The climate benefit of working from home and video conferencing can even increase with the right transmission methods and more efficient data centres.

“My goal is to capitalise on the German EU Council Presidency to reach a common position on environmentally friendly digitalisation because the best approach would be to set good standards throughout Europe., added Schulze”

Dirk Messner, President of the Federal Environment Agency, said: “This is good news for people who like to watch movies and series. You can use streaming services at home with a fibre optic cable or VDSL without having to feel guilty about the climate.”

But the volumes of data all around us will grow steadily over the next few years, be it in the form of networked vehicles, home cinema or video conferencing. This is why it is important to find climate friendly transmission channels. The research shows that investments in expanding fibre optic networks will help reduce carbon emission. The new 5G transmission technology is also promising in terms of climate change mitigation, according to the research.

More and more people are using cloud services. The coronavirus pandemic has further increased demand: the use of streaming services and cloud gaming rose by 30 percent between February and March 2020.

In March 2020, a peak value of 9.16 TBit (terabits) of data throughput per second was measured at the world’s largest Internet node in Frankfurt am Main (DE-CIX). This is equivalent to the simultaneous transmission of more than two million HD videos and is the highest value ever measured at this node.

Reliable figures on how cloud services such as video streaming or online data storage systems impact the climate have not been available to date. Previous studies have yielded very different results, in part due to the use of different methods or different data. However, what all the studies have in common is that the findings are based on calculation models and assumptions rather than on real measurement data. Current data from the German Federal Environment Agency on the environmental impact of cloud services makes it possible to calculate the carbon footprint of data-intensive services such as video streaming, video conferencing and online data storage more realistically than in the past. Data was measured in a large streaming data centre, among other places.

How can viewers reduce carbon emission?

The study also looked at the data volumes for different video resolutions. Transmission in ultra-HD resolution on a TV requires ten times as much data as HD quality, in other words 7 GB per hour instead of 700 MB per hour.

Users can reduce CO₂ emissions by watching films at a lower resolution. For devices with a small display, the difference in quality is not even perceptible to the human eye.

Videos are a popular tool in website design. Promotional videos often start automatically as soon as the video windows are in the visible screen area to draw the user’s attention to the advertisement. This causes considerable traffic. In the interest of climate change mitigation, website operators
should refrain from using such promotional videos. In addition, the autoplay function should be switched off by default, thus giving users more autonomy over which videos they would actually like to watch. This can conserve data and reduce CO₂ emissions.

Mobile Network has a larger Ecological Footprint

The study also mentions that data transmission in mobile networks has a significantly larger ecological footprint than that of wired broadband networks. The difference between video calls and voice calls is 300 megabytes an hour instead of 60 megabytes meaning that video calls consume 5 times more mobile data.

Mobile network tariffs that incentivise greater data consumption
are bad for the climate.

These findings were compiled on behalf of the German Federal Environment Agency by the Öko-Institut and Fraunhofer Institute for Reliability and Microintegration (IZM) as part of a Green Cloud Computing research project. The calculations are based on data recorded in data centres and data from technical data sheets. The complete results and the final report are expected in December.