Do you have your lengthy "to watch" list ready for when you get home from work and turn into a couch potato? Just last year, the trendy Korean drama "Squid Game" not only triggered a surge in views but also caused an upswing in internet traffic, causing disgruntled telecom operators to sue Netflix for not paying extra traffic and maintenance costs. This also led to a renewed discussion on the energy consumption and carbon emission controversy behind video streaming services.

How much carbon footprint is generated by using streaming video platforms?

Data transmission + data centers, each accounting for a percentage of global power consumption

The pandemic that spanned the past two years has made the home economy and online services very profitable. But, after watching Netflix for so long, do you know how much electricity is consumed and how much carbon is emitted? This article refers to analyses made by the International Energy Agency (IEA) and the well-known climate media Carbon Brief to give you a better picture.

Streaming services are related to carbon emissions because it requires much equipment, network infrastructure, and remote data centers to play the video you clicked on, which consumes a lot of power in the process. At the end of last year, the IEA released data indicating that the use of video streaming, online games, and social media across the world increased dramatically in 2020, causing global Internet traffic to skyrocket by more than 40% that year!

Fortunately, the efficiency of data transmission and data center operations in recent years has increased significantly, allowing relevant energy consumption to be better controlled. Excluding cryptocurrency mining, these two power-eating monsters (approximately 250 TW) each take up roughly 1% of the world's terminal power demand.

However, the IEA also warns that various internet applications will continue to grow in the future. On the one hand, technologies such as 5G, blockchain, machine learning, and deep computing are maturing. On the other hand, entertainment products such as audio-visual media, online games, and even metaverse will only become ever more popular. Just this year, the various streaming services mentioned above will account for nearly 90% of consumer internet traffic.

To answer everyone's question: what is the environmental cost of viewing Netflix for one hour? The IEA’s answer, using 2019 data, is 0.077 kWh of electricity and 36 grams of CO2! Such a carbon footprint is not far from that of a high-speed train (32~38 grams of carbon emission per person, per kilometer).

One hour on Netflix almost equals the carbon footprint generated by taking the high-speed rail

The results mentioned above show a considerable discrepancy from past reports. Yahoo, the New York Post, Deutsche Welle, and other media have cited the French think tank, the Shift Project, saying that watching half an hour of Netflix (about the length of a limited series episode) will produce as much as 1.6 kg (1600 grams) of carbon emissions.

The difference is because the study overestimated Netflix's bit transfer rate (bit/s, the amount of data transferred or processed per unit of time). The energy intensity of data transfer and data centers used by the Shift Project is 35-50 times higher than that of the IEA! The amount of data transfer and the associated power consumption thereby increased as well. Later, the Shift Project issued a correction in June 2020 and revised Netflix's carbon footprint down to 200 grams per hour. However, this is still much higher than the IEA's calculations.

It is worth mentioning that media players also impact the carbon footprint of streaming video and audio. For example, watching Netflix on a 50-inch LED TV consumes five times more power than a laptop and 100 times more power than a smartphone! This shows that, compared to other 3C devices, smartphones are more efficient in data transmission and consume less power. Whether watching videos on a small screen for prolonged periods is too strainful on the eyes is another matter.

With the current digital trend, watching videos online has inevitably become an indispensable daily entertainment for many people, thus leading to the continuous increase of related energy consumption and emissions. The IEA reminds readers that apart from improving energy efficiency, decarbonization of the overall power structure is the key to reducing the carbon footprint of streaming video and audio. This is also why many IT giants have been increasing the procurement of green power.

Data Source
Data Centres & Data Transmission Network
https://www.iea.org/reports/data-centres-and-data-transmission-networks
The carbon footprint of streaming video: fact-checking the headlines
https://www.iea.org/commentaries/the-carbon-footprint-of-streaming-video-fact-checking-the-headlines
Factcheck: What is the carbon footprint of streaming video on Netflix?
https://www.carbonbrief.org/factcheck-what-is-the-carbon-footprint-of-streaming-video-on-netflix