This page would be better for the environment without this photo, but at least it’s not a video.

Because the digital sector must find its place in the face of the rapid and massive reduction of greenhouse gas (GHG) emissions defined by the Paris Agreement and the COPs. Because the digital sector depends on many other sectors that will have to transform rapidly and affect global material structures (energy, mining, logistics, etc.). Because the environmental crisis increases the risks to many links in the sector’s extraction, supply and manufacturing chains.

According to the work of Charlotte Freitag et al. of Lancaster University, which synthesised and adjusted the various estimates, the carbon footprint of the digital sector would represent 2.1 and 3.9% of global emissions in 2020. The uncertainty is linked to the difficulty of obtaining data from the sector’s manufacturers and the opacity of the manufacturing chains. Thus, it is more rigorous to provide a range.

Projections beyond 10 years are not used as there are too many uncertain factors in the evolution of the digital sector and associated technologies. Andrae estimates that the footprint will continue to grow slowly (1269 MtCO₂e by 2030) while Malmodin projects the footprint to halve by 2030. There are many factors that can affect the evolution of the footprint so projection is a perilous exercise. In any case, despite the increasing digitalisation over the last 20 years, the major environmental trends (increasing GHG, energy consumption, material footprint) have continued to rise.

The way emissions are accounted for in the two sectors are different, the scopes of calculation are not the same and the two sectors do not serve the same purposes so there is little point in comparing the two. The comparison was used to communicate that the digital sector has material and climate consequences like a highly visible sector, aviation. Once the materiality of the digital sector has become part of the collective unconscious it will be wise to abandon the metaphor.

Greenhouse gas emissions from the digital giants can be reduced through massive investment in renewable energy. Not all players in the sector can do the same and they will use carbon offsetting to reduce their emissions from an accunting perspective. So carbon emissions can be kept under control. It is clear that a massive shift in environmental impacts is taking place from the use phase (electricity consumption and related emissions) to the manufacturing phase (which is generally outside the responsibility of service companies). That is, the reduction of GHG emissions related to electricity consumption comes at the cost of increased consumption of materials, energy and water during the manufacture of equipment.

To understand both positive and negative effects, it is necessary to have access to good quality, representative open data. Open data allows it to be independently audited by several actors to verify its reliability. Access to good quality data depends on the ability of researchers and experts to obtain real measurement data (primary data). The representativeness of the data will depend on the scale at which one wishes to extrapolate the results. Today, very few of these conditions are met and experts use global models to extrapolate their results in space and time.

We are slowly beginning to see more clearly the environmental footprint of the sector but the methods for estimating positive impacts (avoided emissions) are far too methodologically weak to be considered. Firstly, although it is easy to model two small scenarios (videoconferencing VS face-to-face conference) it is very complicated to integrate the effects of digitalisation at larger scales where there are many more factors to integrate. Secondly, the estimates aim to incorporate enablement effects, i.e. where the digital sector can reduce emissions from other sectors, but they do not incorporate enablement effects that increase emissions (e.g. increased oil barrel production due to the digitalisation of an oil platform). As such, the few estimates present a gross balance of gains and not a net balance (emissions avoided – emissions added).

Between 196 and 400 TWh worldwide. The variability is explained by the data sets used and the assumptions about the development of hyperscalers around the world. Whatever the global consumption, the location of data centres poses real questions of planning and energy transition at local level, as in Dublin, Singapore or Frankfurt for example.

There are two ways to report the power consumption of digital networks in the environmental footprint calculation. The conventional approach is to take global indicators such as data transfer and equipment power consumption to obtain a kWh/GB ratio. This approach allows for a posteriori accounting and all power consumption is allocated equally. The power model approach consists of allocating the base consumption of the equipment to each user/subscriber and then marginally allocating the surplus electricity related to the service used. The conventional approach is suitable for corporate environmental accounting and on a large scale, the power model approach is suitable for dynamic modelling of the power consumption of a data-carrying equipment/service. Whatever the approach, the power consumption of data centres and user equipment is calculated from the time of use.

Whether they are in use or not, digital infrastructures (data centres, networks) are always more or less switched on, so their consumption does not vary much according to data traffic. Similarly, the renewal of user equipment or the construction of new data centres is not directly related to data traffic. Thus, reducing global traffic does not directly reduce the environmental impact of the sector. However, if global traffic were to stabilise, one might assume that this would indirectly encourage a slowdown in the construction of new infrastructure. But traffic is only one factor among many that structure the development of the sector.

The discussion was launched following the Shift Project’s report on the issue. Many major media outlets subsequently reported the estimates. However, the think tank made several calculation errors, pointed out by George Kamiya of the IEA, leading to an overestimation of the carbon impact of online video. Today, the white paper co-authored by the Carbon Trust and numerous researchers and experts on the subject is a reference. Streaming on Netflix is estimated at 100gCO₂e per hour, video streaming in Europe is estimated at 56gCO₂e per hour. These estimates only take into account the usage phase of the digital infrastructure and exclude the impacts of the manufacturing phase. Within this limited scope, the main source of electricity consumption is the television set (smart or not). The electricity mix of the country where the consumption is located varies greatly in terms of CO₂e emissions, and there is little variability in the footprint depending on the resolution (this is linked in particular to the allocation method).

All the necessary national and European policies must be put in place to extend the life of equipment, reduce the purchase of digital equipment over time and stabilise the development of digital infrastructure (data centres, networks) in order to benefit from efficiency gains.

At the individual level the most important actions are simply to keep your equipment for as long as possible, not to buy new if possible and to avoid over-equipment per person or per household. In an ideal world we should aim for consumer equipment (smartphones, etc.) with a functional life of 10 years.