Behind the scenes
of digital footprint measurement

In methodological terms, what are the existing approaches to measuring the digital footprint?

There are several ways to assess the digital footprint. In Anglo-Saxon countries, single-criterion analyses dominate. For example, carbon assessments are carried out to measure the environmental footprint of a data centre. With this type of method, not everything is considered and factors involved in the manufacture of components are not included.

Another approach, multi-criteria life cycle assessment (LCA) is a comprehensive approach. The ADEME (French Agency for Ecological Transition) began promoting this methodology in the 2010s and it is particularly prominent in France in the field of environmental analysis. LCA serves as a framework for companies and can be used as a lever for financing certain actions. The method is ISO standardised.

Complementary to carbon footprinting, life cycle assessment is a standardised assessment method (ISO 14040 and 14044) used to quantify the environmental impact of a system (product, service, company or process) throughout its life cycle: from its design (extraction of raw materials for a product) to its end of life (recovery, recycling, disposal, etc.). Thanks to its comprehensive, multi-system and multi-criteria approach over time, LCA enables companies to communicate transparently about the environmental performance of their products and industrial systems.

Beyond the process itself, LCA is a subject of scientific development with dedicated communities constantly striving to improve the way reliable data is produced. LCA is also a subject of expertise, with the usual tensions between scientists and consultants, the former questioning the rigour of the latter and the latter questioning the difficulties of implementing an approach that is not flexible enough. This is one of the main operational challenges of LCA: obtaining credible results in terms of rigour using an approach that can be implemented.

When using life cycle analysis, it is necessary to collect reliable data on equipment production processes, terminal usage, data centres and networks. This data is not always easy to collect. It may be subject to trade secrets or be difficult to access due to long value chains.

What is the regulatory aspect?

Since the REEN law (the law on reducing the environmental footprint of digital technology, enacted at the end of 2021), ADEME and Arcep (the French regulatory authority for electronic communications, postal services and press distribution) have set up an observatory to monitor the environmental impact of digital technology. The aim is to quantify the direct and indirect impacts of digital technology on the environment and its contribution to the ecological and solidarity transition.

The findings of the observatory on the environmental impact of digital technology have been made public. In mid-April, Arcep published the fourth edition of its annual survey, ‘Pour un numérique soutenable’ (Towards sustainable digital technology), which presents data collected from digital players in order to report annually on the evolution of their environmental impact in France. Specifically, Arcep has the power to collect information from digital companies and has been mandated by the legislator to compile this overview. The institution began by monitoring telecommunications network operators in view of its historical links with these players, then gradually expanded its data collection to include other digital players, data centres, terminal manufacturers and all other digital components that were not originally part of the institution's historical scope.

The value of Arcep's annual report on digital technology is that it provides a basis for comparison. Interest in these issues is very recent. We are only just beginning to take an interest in the digital footprint in France and we are one of the countries that is giving the most thought to this issue, even though we entered the digital age globally several decades ago... Arcep plays a leading advisory role to BEREC, the Body of European Regulators for Electronic Communications. If we compare ourselves to our neighbours in terms of environmental policy, Germany has been more aggressive in imposing restrictions on heating networks by making them mandatory and some countries, such as the Netherlands and Ireland, have adopted approaches to better regulate the pace of arrival and spatial dispersion of data centres.

What are the main challenges today, in your opinion?

Accurately measuring water footprints remains a real issue. First, we need to agree on the terminology. What are we talking about? Are we measuring water withdrawal or water consumption? Because they are not the same thing. Water withdrawal returns to its environment, whereas water consumption does not. For data centres, for example, this will depend on the cooling system used. When water circulates in closed cooling loops, we can consider that the water is withdrawn from the environment and that, after passing through a heat exchanger system to cool the servers, it will return to the environment after a decontamination process if necessary. When the server cooling system uses droplets, based on the physical phenomenon of evaporation, water is consumed without being returned to the environment. This is not the dominant mode of operation in France, but in the United States and other countries, this type of cooling system, known as “adiabatic”, is still very widespread. The water then leaves its natural cycle and does not return to the environment. The long-term risk is that the downstream area of the data centre will be deprived of a relatively large amount of water and/or that the water table will be impacted, eventually leading to conflicts over its use.

A second issue concerns the reference framework. Companies have been using life cycle analyses for a long time, with a view to eco-design, generally at the production engineering level. In R&D, the quest to reduce consumption is a driver of innovation, but in this case, the data and reference framework remain internal to the company and are not communicated externally. When we seek to use a single reference framework as a tool for public policy, it becomes more complex. The eco-design data and methods used by companies are not uniform, and the way in which LCAs are applied differs from one company to another, even when complying with the ISO standard. However, if data is not produced in the same way, it is difficult to compare it. The challenge here is therefore to design a consistent database.

A few years ago, a consortium was formed, comprising four private entities: LCIE/Bureau Veritas, APL Data Centres, the GreenIT.fr collective and DDemain. The aim was to set up a database entirely dedicated to digital ecological assessment. NégaOctet – as the platform was called – sought to develop and test a framework for assessing the environmental impact of digital services based on an LCA approach. This concerned data exchanged via the internet (4G, fibre, etc.), data stored in data centres, data related to hosting and information processing (switches, firewalls, routers, storage) and data from consultation terminals and sensors linked to connected objects. Access to data on this platform was subject to a fee. With IT evolving so rapidly, it is very costly to keep such a database up to date and to accurately assess the digital footprint of components that are constantly changing. Access to NégaOctet is no longer marketed by the consortium. Given the growing importance of the subject, Ademe has launched another initiative and funded preliminary studies to see how such a digital database could remain public, free and up to date, involving the CNRS and Inria.