If you want to calculate your personal carbon footprint of digital content, you can consider different content formats, such as video, audio, images and text. Of these formats, video is the format of content that is most energy-intensive. Measuring the carbon footprint of video, however, is difficult, because it is distributed across several touchpoints, and system boundaries are set differently depending on the research (see part 1 of this series for the explanation of why it is difficult to measure).
Also, studies suggest distinguishing between ‘regular’ streaming of video (one-way) and the emissions of videoconferencing, as the latter is streaming and sending video data at the same time (both ways). Learn here about approaches to calculate the carbon footprint of video streaming and videoconferencing.
The carbon footprint of video streaming
As stated above, studies for measuring the carbon footprint of video consumption vary in their results: While researchers of one study calculate streaming a video at a 1080 p resolution to need 12.5 kW per hour and thus emitting 8.8 kg CO2e, other researchers found one viewing hour to require 2.91 kW and to emit 0.42 kg CO2e. These differences result from the approach to estimate energy use of data storage and transmission, as well as video resolutions.
Since the first study works with more recent data and provide a comprehensive calculation basis for CO2e emissions produced by streaming video depending on its resolution, this study is taken into account in this post. Thus, one can calculate video emissions the following way:
hours video length
* GB per hour for a given resolution
* 4.91 kWh/GB (energy intensity)
* number of unique viewers
* 0.256 kg CO2/kWh (greenhouse gas emissions by the UK government)
= carbon footprint in kg CO2e
The energy intensity of 4.91 kWh/GB considered here displays the average of two studies for Sweden and for the UK. This analysis seems to include larger system boundaries for video streaming.
For the GB per hour for a given resolution of a video, following the quoted study, one can use these measurements were studied on Netflix:
- 480 pixels: ~ 792 MB/hr
- 720 pixels: ~ 1.3 GB/hr
- 1080 pixels: ~ 1.9-2.55 GB/hr
- 1440 pixels: ~ 2.8 GB/hr
- 4K: ~ 3.5-7 GB/hr
Streaming one hour of video content in 4K (7 GB/hr) would thus result in 8.79 kg carbon emissions, comparable to driving a petrol-fuelled car for about 48 km.
The carbon emissions of videoconferencing
One study about videoconferencing and its emissions states that a videoconferencing tool requires approximately 2.5 GB per hour, which in their calculation is equivalent to 157 g CO2e/hr. One person having 15 video meetings of one hour per week would result in 9.4 kg CO2e in a month. By simply turning off the video while calling, monthly emissions would drop to 377 g CO2e, or 6.2 g CO2e/hr, saving 96 % of emissions per hour of meeting online. If one million information workers turned their camera off for their estimated 15 monthly calls, they would save as much CO2e as is emitted by burning coal to power a town of 36,000 inhabitants.
As you can see, video streaming and videoconferencing is indeed quite emission-heavy. Consider estimating your carbon emissions from the formulas quoted above and in the next step, reducing it in order to be more digitally sustainable.