Digital services also have a physical value chain
Watching a video, streaming music or using a cloud service may seem intangible. Yet these services depend on devices, telecommunications networks and data centres. Manufacturing equipment requires materials and energy; using it consumes electricity; and the infrastructure needs maintenance and replacement over time.
Life Cycle Assessment (LCA) makes it possible to examine these contributions together, from equipment production to infrastructure operation and end of life.
What the YouTube study set out to measure
A study by Preist, Schien and Shabajee examined YouTube’s digital services during 2016 and estimated the greenhouse-gas emissions associated with platform use. It considered several parts of the value chain, including user devices, transmission networks and data centres.
For that year, and under the study’s assumptions, the authors estimated electricity use of 19.6 TWh and associated emissions of 10.1 million tonnes of CO₂ equivalent. These are historical model estimates for 2016—not figures for YouTube’s current footprint, and not values that should be extrapolated to other services without analysis.
The authors also explored design and usage scenarios that could reduce data transmission in specific situations, such as providing audio only when visual content is not needed. The relevance of any intervention depends on user behaviour, technology and the infrastructure involved.
Where do the impacts occur?
The footprint of a digital service may include:
- manufacturing and replacing computers, phones, televisions and network equipment;
- electricity consumed by user devices during operation;
- data transmission through fixed and mobile networks;
- operation and cooling of data centres;
- construction, maintenance and end of life of infrastructure.
The relative contribution of each stage varies with the service, equipment, location, electricity mix, network efficiency and device lifetime.
The methodological challenge
LCA of digital services requires clearly defined boundaries and representative data. The functional unit must be explicit—for example, one hour of video streamed at a specified quality—as must assumptions about devices, traffic, server utilisation and the allocation of shared consumption.
Digital-service emissions also create challenges for corporate GHG accounting. The GHG Protocol organises emissions into Scopes 1, 2 and 3, but practical application to digital services depends on how an organisation defines its value chain, collects data and avoids double counting. LCA provides a complementary service-oriented, life-cycle perspective.
The 2016 example remains useful as a methodological illustration. Current decisions, however, require recent data specific to the infrastructure and service being assessed.