The digital carbon footprint

The usage of information and communication technologies (ICTs) – computers, smartphones and in general any device using telecommunications – is not exempt from the emission of greenhouse gases, since the electricity needed to run them mostly comes from non-renewable energy sources, specially coal. Understanding carbon footprint as the amount of carbon dioxide released into the atmosphere as a result of the activities of a particular individual, organization, or community, the concept of digital carbon footprint concerns all those activities related to ICTs.


Since the invention of the Internet more than 50 years ago, the usage of information and communications technologies (ICTs) has grown tremendously, up to the point of even becoming essential for our daily survival in some specific situations. Technologies such as telecommunications, geolocalisation or robotics have enormously improved some of the most important fields in society, like the health sector or education; meanwhile ATMs, printers or social media have made our jobs and day-to-day activities more efficient and engaging. 

As an example of this worldwide digitalisation, a study recently published by Digital Economy Compass gathered some of the activities carried out on the Internet during a period of 60 seconds, among which are more than 3.8 million Google searches, almost 700.000 hours of content watched on Netflix and more than 188 million of mails being sent. If we compare this data with the one obtained from the same analysis in 2016, we may start noticing how fast this sector is evolving.

Estimated data created on the internet in one minute in 2019. Source: Statista 2019


Estimated data created on the internet in one minute in 2016. Source: Excelacom



Notwithstanding, the colossal development experimented by information and communication technologies does not come for free. The aforementioned frenetic data exchange entails huge CO2 emissions, which are mainly related to the electricity consumption used for the running of the infrastructure supporting the information transactions and the usage of ICTs at commercial and residential scale. 

Since the majority of the electricity required by the ICT sector is still produced by means of fossil fuel power plants, the usage of digital technologies results in the emission of huge amounts of CO2 into the atmosphere. Although renewable energy power plants and other low carbon technology projects are being massively put in place, the current installed capacity only accounts for the 35% of the worldwide electricity produced. 

World gross electricity production by source in 2017. Total fossil fuels: 64.4% (coal: 38.3%, oil: 3.3%, natural gas: 29.1%). Source: IEA Electricity Statistics 2017


Electricity consumption associated to ICT infrastructure

Information and Communication Technology (ICT) infrastructure is essentially composed of data centers, facilities consisting of networked computers and data storage that companies and other organizations use to organize, process, store and disseminate large amounts of data. Data centers are a critical asset for the business operation and continuity, and are therefore equipped with redundant and backup components, data communication connections, environmental controls (such as air conditioning or fire suppression) and security devices, among others. This incredibly complex ecosystem requires the consumption of great amounts of electricity that, in the case of large industrial-scale data centers, can equalize the electricity consumption of a small town. 

Whereas the electricity used to run the servers remains at a constant rate throughout the year, the electricity required for keeping them at an appropriate temperature drastically increases during summer. In the same way your computer warms up when it has to carry out several tasks at the same time or when you execute a heavy program, data centers represent an incredibly big source of heat. Since the power electronic devices from which data centers are made of tend to underperform above 40ºC, a rigorous air temperature control has to be set up, implying the use of cooling devices, usually air conditioning machines. 

Facebook’s data center Altoona Online.  Source: Facebook

Electricity consumption associated to the ICTs at home

Owing to the great amount of alternatives offered by ICTs, our behavioural patterns are changing, which directly alters the use of resources, such as electricity. The 2016 edition of the World Energy Outlook, conducted by the International Energy Agency (IEA), determined how electricity demand profiles are affected by the residential usage of ICTs such as TV or the Internet. As seen on the picture below, the employment of such technologies modified the shape of electricity demand curves, increasing the electricity consumption during the afternoon and the evening. 

Figure 1 Electricity demand profiles load curves for Spain and Sweden and as a function of three different activities: entertainment, cooking and work & study. Source: World Energy Outlook 2016 (IEA)

Total electricity consumption and CO2 emissions associated to ICTs

Overall, according to the Swedish researcher Anders Andrae, Global computing power demand from internet-connected devices, high resolution video streaming, emails, surveillance cameras and a new generation of smart TVs is increasing 20% a year, consuming roughly 3-5% of the world’s electricity in 2015. Extrapolating this data into CO2 emissions, a 3-5% of the world’s electricity produced in 2015 entailed the emission of 972-1620 Mt of CO2 (IEA CO2 Emissions Statistics), a higher amount that the one produced by the aviation sector (Air Transport Action Group).  In his study, Andrae also developed four different scenarios forecasting the evolution the electricity consumed by ICT, with percentages ranging from a 9% share to a 20% by 2025, which would make the ICT sector emit as CO2 as half of the worldwide transport sector. 


ICT share of global electricity usage as a function of four different energy efficiency scenarios. Source: Climate Change News. Credits: Anders Andrae.



Fortunately, there exist several solutions to help tackle the CO2 emissions issue and keep enjoying all the benefits that ICTs provides us. Most of the solutions are being developed at company level, however there is a huge room for improvement at home level too. Here are some examples.

What companies are doing at data center level to reduce ICT-use-related detrimental environmental effects 

  1. Free cooling as an alternative to air conditioning. During the cooler months of the year, outdoor cold air can be used to reduce indoor temperature of the rooms where data centers are in, instead of turning on air conditioning. 
  2. Specifically locate data centers on cold environments. Be it countries with cold weather, so free cooling can be used throughout the whole year and not only during winter, or under the sea, so cold seawater can be used to refrigerate the ICT infrastructure.
  3. Signing a Power Purchase Agreement (PPA) with renewable energy providers in order to guarantee that part or all of the electricity consumed by the data center comes from no-carbon-emitting sources. Companies such as Google, Microsoft or Facebook have signed these kind of agreements. 
  4. Reduce cooling requirements by employing power electronics devices withstanding higher temperatures. If technology withstanding 50ºC instead of 40ºC is used, this 10ºC difference will directly translate into electricity savings, as less energy from the cooling system will be required. 

What you can do at home to reduce ITCs-use-related detrimental environmental effects 

  1. Erase your unnecessarily stored online data. Apart from allowing information transaction, ICT infrastructure is also in charge of storing data. For instance, cleaning your email account from old or out-of-date messages you will be saving up to 1 gram of CO2 per mail (ecoinventos). This can also apply for unused email or social media accounts, since they still have saved plenty of emails, pictures or posts. An app that may help you deal with big amounts of spam or unread newsletters is Cleanfox, which will also donate part of their profits to the reforestation of Zambia.
  2. Reduce the amount of information that you receive. Related to the previous point, if we unsubscribe from newsletters or ads from products we are not interested in, or decide not to receive a warning every time somebody likes our posts on Facebook, LinkedIn or Instagram, we will be avoiding CO2 emissions as well. 
  3. Use search engines that donate part of their profits to reduce our carbon footprint. One example is Ecosia, which donates 80% or more of its profits to non-profit organizations that focus on Reforestation.
  4. Contract 100% renewable electricity. Likewise some ICT companies do (Facebook, Google…), we (the users) can hire our electricity supply to retailers who purchase 100% renewable electricity.
  5. Reduce, reuse and recycle. Taking into account that the manufacturing of ICT devices, such as televisions, computers or smartphones, also entail CO2 emissions (mainly related to the extraction of raw material, its transformation into the final product and its delivery) avoiding the unnecessary purchase of new products will also help reducing the detrimental effects that this sector has on the environment. 

Although it seems that these steps only represent the savings of a little amount of CO2, now imagine that each of us (more than internet users worldwide) decided to erase 1 email from our account. That would be 2 million kg of CO2 saved from being emitted.


Written by: Eloi Delgado Ferrer – Master’s in Renewable Energy and Energy Management

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