As the digital economy skyrockets, so does its environmental impact. Responsible for 3.5% of greenhouse gas (GHG) emissions in 2019, the figures for digital have overtaken the aviation sector (2.5% in 2018); a divide further accentuated by the pandemic. Between 2015 and 2019, energy consumption of the digital sector in the world increased by 6.2% per year1, in part driven by the soaring sales of wireless devices like smartphones, tablets, laptops, printers, TVs, other industrial devices or even surveillance cameras. As we head towards 2025, projections show that GHG emissions of the digital economy is likely to increase to as much as 5.5% (with a high risk of going beyond even that to reach 9%) and that wireless devices have been labelled as an important avenue.
Recent reports from The Shift Project point to the “Internet of Things” (IoT), the plethora of connected devices we use on a daily basis, as one of the main causes of GHG emissions for the sector. Of the categories contributing to the environmental impact of the digital sector, connected devices have shot up from causing only 1% in 2010 to a projected 18–23% in 20252. Less surprising when you consider that estimates from 2021 show, on average, each person in Western Europe owns 9 digital devices. And, whilst back in 2010 there were ~1 billion devices in the world, according to various estimates, there will be somewhere between 30 and 50 billion by 2025 and as many as 100 billion in 2030. Hence, the global data is clear – the number of connected devices is increasing exponentially driving up our digital-fuelled environmental footprint.
Focus on production and usage
“GHG emissions due to connected devices come from both their production and use. It is generally considered that half of the energy consumption concerns the production of objects, the other half their use,” explains Chantal Taconet, lecturer in computer science at Telecom SudParis. For example, figures from the ADEME show that over the lifetime of a 2kg computer it will generate 169kg of CO2 – of which as much as 124kg is from its production.
She points out that a big part of the solution lies in the lifespan of our devices, “taking into consideration the production and use of connected devices, we can evaluate how long we should use an object or piece of equipment – in months or years – to minimise the environmental footprint. We are starting to model this calculation by integrating all the parameters.” She cites the example of a connected thermostat, “we should consider the quantity of the item to be produced, cost of manufacturing, cost of use, estimated life span, etc. From that, we can evaluate an appropriate lifespan to maximise on the environmental benefits.”
Such calculations could tell us, for instance, based on the number of kilometres travelled per year and according to the country [CO2 emissions of electricity production differs according to the country] how many years an electric car owner should keep their car to obtain the real benefits in terms of CO2 compared to a thermal motor car. At Telecom SudParis, she teaches the new generation of digital engineers, “we encourage students to ask themselves the right questions when designing a new system ; to decide whether or not to produce this new object ; whether they can expect gains in an acceptable timeframe ; and, if so, how to ensure that the system consumes as little energy as possible.
Innovations in data transfer
“During their life, connected devices produce huge amounts of data traffic between these objects and the servers that process the data, whether that be in the cloud or other systems such as Edge or Fog Computing.” In fact, for connected objects, the question of environmental efficiency arises quite early in the development process, because the consumption of the object itself must be reduced to optimise the size and life of its battery.” For example, researchers are studying how to make detectors ‘sleep’ and ‘wake up’ so that they only wake up when they have something to emit.
In her research, Chantal Taconet’s work goes beyond detectors, she integrates energy efficiency issues into the design of new software. “Personally, I conduct research on distributed systems and the role of software, or ‘middleware’, which enables data exchange between distributed application components. My research concerns the entire chain of events from detection to downstream software that is controlled via clouds. We will see the biggest improvements in energy consumption if we reduce transmissions from the whole chain. As such, a sensor only transmits when necessary and clouds filter in such a way that they only transmit to applications when it corresponds to a specific requirement.” For instance, transmission signals are different depending on whether a wireless sensor is installed on top of the Eiffel Tower to inform periodically weather stations or installed in a classroom to monitor the average temperature.
She also sees a key to the solution as finding a way to improve efficiency of data transfer through distributed architecture. For example, she is looking at architecture innovations such as cloudlets, or small clouds, which are installed near data sensors. “The question is whether or not it is good – in terms of environmental impact – to have proximity clouds or not. On the one hand, yes, it is good, because it reduces the number of intermediaries for the transmission of data between producers and consumers. That said, we don’t know where the producers and consumers of this data are located. So, you need routers and software servers that distribute the data to those who will use it. On the other hand, it may be better to use central servers and thus limit the number of devices.” 5G is another area that illustrates the kind of problems the digital sector will need to solve. “For the same amount of data transferred, 5G is cheaper on the terminal side. But it overlaps with existing technologies. In fact, 5G multiplies equipment and antennas. And increased throughput always means increased usage.” Yet, overall, she concludes that to reduce energy consumption and greenhouse gas emissions, “we need to act by reducing the number of devices in use and on the production of new objects. This is the nerve of the war!”
Turn off your box
Advice for users of other types of digital devices (not necessarily connected objects) includes switching them completely off when not in use. The ADEME, for example, in their report state that “the total consumption [of an internet/TV box] over a year is between 150 and 300kWh : as much as a large refrigerator!” Also pointing out that “43% of people never switch off their box and 41% only switch it off when they are away for a long time.” Hence, from the user’s point of view, there are simple steps that could help reduce environmental impact. In a report by GreenIT, they also suggest consolidating connected devices into one, to improve overall efficiency.
