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Topics that will affect the future such as machine learning, virtual reality and blockchains are making a profound change to our world. Both with the opportunities they offer us – and with their environmental impact. However, while we do have these cutting-edge technologies, we should not underestimate the influence of traditional ICT.

Not only is the rate of digital adoption steadily rising across the board, but the use cases are also becoming more and more complex and consuming exponentially more resources. Although systems and their hardware themselves are becoming more efficient, Jevon’s Paradox – also called the rebound effect – means that these efficiency gains are causing higher production and consumption and only generating a lower environmental impact in rare cases.

As one of the fastest growing industries, the environmental impact of the digital economy is becoming increasingly problematic and has long since caught up with global air travel in terms of CO2 emissions. We will show you what the effects are and what we need to start doing now.

Sustainability has many forms

Software does not consume electricity, hardware does. But we use hardware to run software. That’s why we calculate electricity consumption based on the software that we run on the hardware.

But the impact that software has isn’t limited exclusively to environmental sustainability. It’s clear from the United Nations’ Sustainable Development Goals that we’re no longer just talking about environmental impacts when we talk about sustainability. The Bruntland Report published in 1987 gave holistic consideration to the dimensions of sustainability in terms of ecological, social and economic aspects.

The scientific literature pertaining to software also frequently examines technical sustainability. This usually involves questions of maintainability and sometimes also longevity. A large amount of helpful work has already been done in this area, although the aspects of social and, in particular, ecological sustainability have been somewhat neglected. Economic sustainability – as a major driver of IT – has also been the subject of investigation since the 1990s. We will focus on environmental and social sustainability in this blog post, so as to give a holistic assessment of the issue beyond the traditional dimensions.

Why green electricity is not enough

The electricity consumption of a computer can be measured using standard household devices, but it’s more difficult with smartphones because of the charge stored in their batteries. Now, if our software is not just a client application, but a distributed system spread across a number of servers in various data centres using third-party services and communicating over the Internet, then we are talking about the kind of software that people use every day these days and that makes up a significant part of the relevant software. This measurement, which is difficult to do, and outsourcing resource-intensive processes to remote data centres, among other things, prevent both consumers and decision-makers in companies from being able to assess the ecological footprint of the software they use.

CO2 emissions

Since we know that our electricity consumption in Germany is not yet completely covered by renewable energy sources – around 41 per cent last year according to the German Environment Agency (Bundesumweltamt) – this electricity consumption also has an impact on ecological sustainability. The CO2 (and CO2-equivalent) emissions generated by electricity consumption are usually factored in to assess its environmental impact. These are calculated from the product of the electricity consumed and its CO2 intensity. For example, just creating a large reusable machine learning model for processing language may well emit 284 tonnes of CO2 – the same amount as continuously streaming Netflix for 600 years would generate. You can also find some of the most important key figures on the environmental impact of software on our digital sustainability website.


Another major environmental factor – besides electricity consumption – is the production and disposal of hardware: the servers, smartphones, routers and all the mice, keyboards and other accessories we make to use software with. With hardware, other dimensions of environmental sustainability such as ecotoxology come into play on top of greenhouse gas emissions when we dispose of e-waste. E-waste makes up the fastest growing share of waste worldwide, around 14 per cent of which is generated in companies in Germany.

In addition to extracting the raw materials from the e-waste, which is often done under inhumane conditions (social sustainability), and the negative effects that the on-average 1,000 toxic substances it contains have on people and the environment, this also has grave economic consequences. In light of this, digital sustainability criteria catalogues such as those of the German Blue Angel (Der Blaue Engel) ecolabel or the German Informatics Society (Gesellschaft für Informatik) require not only that software programs consume a low amount of electricity but also that aspects such as backward compatibility with older hardware and low hardware utilisation when in standby mode are integrated.

Ultimately, one blog post is not enough to describe all the environmental impacts of software. Other impacts range from a scarcity of water caused by cooling data centres, to indirect impacts such as deforestation and a reduction in biodiversity and more.

Inclusive digital solutions

Turning our attention to usability and accessibility, aspects of social sustainability have been part of common standards such as ISO 25010 for software quality for over 20 years. Beyond this, however, there are still many aspects of social sustainability that researchers have only been tackling for a few years. These range from non-inclusive language in IT, such as the designation of ‘master and slave’ nodes in the Bluetooth standard or terms such as blacklists and whitelists, to the direct impact of software on our daily lives.

We see these direct impacts in older people who are excluded from participating in society due to their lack of digital literacy, and range from data autonomy in terms of tracking and online advertising to complex challenges such as fake news and human rights violations.

For many of the phenomena mentioned, it’s no longer possible to get a clear picture of whether they are direct effects of producing and operating software, or whether it’s just the use cases of the software that are unsustainable.

Should we really be doing this?

This is the question we inevitably have to ask ourselves when implementing software use cases. We can influence a lot of the decisions made in the design and implementation of software that make the final product more sustainable. However, if the intended use of the software affects the health of people and the environment and it functions more efficiently and/or it is more cost-effective due to having a more sustainable technical design – or to put it another way, it also sells better – little is gained in terms of sustainability. The rebound effect mentioned earlier in the introduction must therefore also be weighed up in relation to the use cases.

Software for sustainability and green tech are some counterexamples to this. Even if we don’t preserve the planetary boundaries through software alone, digital solutions offer massive potential to counteract climate change and have a positive influence on the other aspects of ecological sustainability such as species becoming extinct.

What we need to do now

Improve expertise

A quick look at the job portals of the big innovators these days (such as Microsoft or Amazon) quickly reveals that they’re no longer focussed on simply just fulfilling reporting requirements. They have understood that sustainability is an issue that will affect the future, which, in addition to increasing the quality of life on our planet, is already creating the profitable business models of the future. New interdisciplinary teams are being formed and new talents are being acquired to take advantage of this. In addition, sustainability is being brought up with current employees across departments, and they are being given the tools see it as an equal requirement in the future.

Take responsibility

Consumers are not the only ones who are responsible for sustainability. Even though oil company BP brought the concept of the personal ecological footprint into the mainstream in 2004, a mere 100 companies are still responsible for 71 per cent of all CO2 emissions. Consumers can make a small contribution – as we demonstrate in our blog post on the CO2 footprint of e-mails – but companies and policymakers are the ones who can have the biggest impact.


Sustainable software engineering is trying to solve many of the challenges in the field of digital sustainability. It combines findings from climate research, energy markets, measurement technology and environmental informatics to understand and improve software across all the dimensions of sustainability.

You can get a sneak preview on the topic in our blogs on Green software engineering in Java (in German) and Green cloud computing. And green tech solutions such as the Planet Hero app or urban energy are also key building blocks for an economically, ecologically and socially sustainable future.

On our website, we’ll show you what goals we at adesso have set for ourselves with regard to sustainability, what measures we want to implement and what the associated opportunities and challenges are for our company.

You will find more exciting topics from the adesso world in our latest blog posts.

Picture Yelle Lieder

Author Yelle Lieder

Yelle Lieder is Green IT Lead at adesso. As part of the CIO Advisory Competence Centre, he focuses on strategies for measuring and reducing the environmental impact of IT systems and on the use of technology to achieve sustainability goals.

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