Cold data storage: an ecological solution for reducing the environmental impact of data

Published on 04 September 2023 Read 25 min

While immaterial in appearance, software currently generates as much if not more greenhouse gases worldwide than air transport [1], and this impact is continuing to grow. At a time when companies are increasingly engaging in CSR transformation plans, changing their data management habits can be a lever for minimizing their environmental impact.

Through a series dedicated to the environmental and social impact of data, Alcimed invites you to explore 3 areas of transformation, including adopting sustainable data management systems, optimizing data storage, and implementing new technologies. In this second category, Alcimed analyzes the cold data storage.

Data: an activity with a high environmental impact

Today, digital technology represents between 2-4% of worldwide greenhouse gas emissions.

Today, many companies are focusing their CSR strategies around actions such as limiting aerial transport or reducing waste. While important, these strategies are insufficient compared to the growing impact of other activities, such as data management. It is therefore important to reassess the priorities of companies and the pros and cons that each of these actions can represent.

Today, data represents between 2-4% of worldwide greenhouse gas emissions; by way of comparison, civilian air transport represents between 2-3% [1]. The transfer and storage of data, as well as the manufacture of electronic components required for the machines, are energy-consuming processes by nature: it has been estimated that the energetic consumption of data centers in 2018 was 205 TWh, or 1% of the total worldwide energy consumption [2]. At the same time, a second study suggests that the amount of data created or replicated per year in the world may increase by 4.5-fold between 2018 and 2025 [3]. If preventative measures are not taken, the environmental impact of data could therefore explode in the coming years – in France alone, it is estimated that data will be responsible for 7% of greenhouse gas emissions by 2040 [4].

Despite a non-negligible environmental impact, data is still under the radar of many companies, and it’s environmental impact is largely underestimated. Three reasons can explain this: the illusion of immateriality of data and their small financial cost can result in excessive generation of data; storage practices that are energy-consuming and not adapted to the data usages; and the novel nature of Big Data technologies and lack of familiarity with them.

Fortunately, there are solutions that can limit the environmental impact of data to slow down or even reverse these trends.

Hot data storage hell

Today, often due to lacking optimization and organization, we have the tendency to store all of our data using “hot storage”.

Contrary to industries based on data transfer such as videoconferences (mentioned in the first category of this series on sustainable data management), the environmental impact of data in most industries is largely due to their storage. Indeed, the difference between data storage and transfer is that the first consumes electricity every day, while the second only consumes at the moment of transfer. Additionally, storage consumes more electricity per byte than data transfer. This is due to our manner of storing data.

Often due to lack of optimization and organization, we have the tendency to store most data by “hot storage”. This means that our data are stored on servers which are accessible at any moment, and therefore permanently turned on. This hot storage method is the most common, but also the most consuming. Indeed, storing 1 GB of shared data on a cloud server, for example, has a carbon footprint of around 15g CO2eq per year in Europe [5], which is more than a trip of 100m in a car. While this may seem anecdotal for a year’s time, we are talking about a single gigabyte; companies generate and store thousands of gigabytes of data every year. The impact of storage is even higher if these collaborative documents are stored on local servers, as they are powered by communal electricity and rarely offer algorithmic optimization of data management, unlike the Cloud. Their usage can still be necessary for cybersecurity reasons. In this case, other storage techniques can be used to limit the environmental impact of our data, such as cold data storage.

Read more: Green cloud computing: a sustainable solution for reducing the environmental impact of data storage?

Cold data storage: a more ecological data storage solution

What is cold data storage?

When the data is no longer used on a daily basis, “cold storage” is sufficient.

Immediate accessibility at any time is not practical for a large part of our data, notably for those that we keep for archiving or compliance reasons, and therefore consult rarely (if ever). When the data are no longer useful on a daily basis, cold storage is sufficient. This technology, which is on the rise for all data storage solution providers (Cloud or not), places cold data in servers which are only turned on upon request; the stored data are thus “frozen” and the servers do not consume energy unless an access request is made. This can slow down the access to information, as the data that are cold-stored can only be consulted several days after the access request. However, this approach considerably reduces electricity consumption linked to data storage [6], and thus their financial costs and environmental impact, by a factor of up to 3.5 [7].

4 steps for adopting cold data storage starting today

Cold storage of data is an effective and easy solution to implement, given that simply migrating data to cold servers is sufficient. Here are the steps to follow for implementing this migration today:

  • Step 1: identify the data currently in hot storage that should be archived
  • Step 2: establish a policy of data management for the future, with periods of hot and cold storage that are well-defined for the different types of data collected (for certain types of data, hot storage could even be completely avoided)
  • Step 3: organize regular and systematic archiving campaigns to ensure that this policy is respected by migrating archived files to cold servers whenever possible
  • Step 4: delete the cold data at the end of the defined storage period

Digital technology has truly become a high-priority environmental challenge whose impact is still exponentially growing, notably due to data storage. Establishing an internal policy that aims to better manage stored data, as well as a larger adoption of cold data storage, can reduce (and even reverse) this trend. In the third and final category of our series, we will explore the advantages of the Cloud in terms of environmental impact. Alcimed is at your side to help you meet your challenges of data storage through a digital sobriety strategy. Contact our team to learn more!

[1] Freitag, C. et al. (2021). The real climate and transformative impact of ICT : A critique of estimates, trends, and regulations. Patterns, 2(9), 100340.
[2] Deluzarche, C. – Réchauffement climatique : le secteur du numérique génère plus de gaz à effet de serre que l’aviation. Futura.
[3] Gaudiaut, T. (2021, 19 octobre). Le Big Bang du Big Data. Statista Infographies.
[4] Sénat (2020). Mission d’information sur l’empreinte environnementale du numérique.
[5] Cloud Carbon Footprint – An open source tool to measure and analyze cloud carbon emissions.
[6] LogicMonitor. (2022). Hot Storage vs. Cold Storage.
[7] Holcman, K. – Comment réduire l’impact environnemental du stockage de données ?

About the author, 

Matthieu, Consultant in Alcimed’s Data team in USA

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