Digital sustainability: calculating our digital carbon footprint with actionable results

At Cambridge University Press & Assessment, we are committed to reducing our environmental impact across all areas of our operations. As our organisation increasingly moves towards digital delivery we are aware of our responsibility to do so in a sustainable way. But whilst we are concerned about the environmental impact of our digital activities, understanding the impact of ‘digital’ on the planet is a complex and emerging area. Chair of our digital sustainability working group, Andri Johnston, discusses our journey to begin to understand and quantify the impact of our digital operations.

What is Digital Sustainability?

When we formed a Digital Working Group in December 2020, digital sustainability was a very new field. As a group we started with a brainstorming session via the online whiteboard tool Miro, to identify areas that we would start investigating, the most critical being our emissions from cloud storage and our digital products, websites, eBooks and apps. 

It quickly became apparent that where we could talk about the carbon footprint of our paper or printing, we could not with certainty answer the question, is digital more environmentally friendly?

To answer this question, we had to understand what the carbon footprint of our digital products was and then, how we could lower this footprint by improving our products. The challenge was both daunting and exciting as we started doing research and looking beyond the publishing industry for information, tools and guidance.

Calculating our Digital Carbon Footprint with DIMPACT

During a first-of-its-kind panel discussion session for the Association of Learned and Professional Society Publishers Redux online conference on Sustainability in Publishing in 2020, I learnt of a tool called DIMPACT. Derived from Digital and Impact, the DIMPACT tool was created by sustainability consultants Carnstone and the University of Bristol to support media companies in the process of calculating the digital carbon footprint of their entire digital workflow.

In late 2020, the Academic Publishing division of Cambridge University Press approved funding for a 12-month trial period of the tool to see how it could be used to calculate the carbon footprint of academic publishing. With a project already underway to move all journals from print to digital on the Cambridge Core platform, we knew this would help us to better answer questions from our customers, for example, librarians concerned whether digital journals are, in fact, a more environmentally friendly option.

A small group of colleagues and two data apprentices set out in early 2021 to collect the data needed to calculate the emissions of the complete academic ecosystem of websites, made up of five individual but connected websites under the Cambridge Core umbrella. The work included all published content from 2019 to 2020 on the websites and their usage across those years.

As we approach the end of our trial period, the tool has helped us to identify that our End User Device emissions made up over 90% of our emissions in 2020. We now know that this is the result of a large proportion of customers accessing our products outside Europe and North America where access to green energy sources is often scarce, particularly in Africa where, for example a large proportion of our products are accessed via mobile usage.

Inspired by the book Sustainable Web Design by Tom Greenwood, we also examined the ‘weight’ of our website and identified a collection of pages with an average page weight of over 3,000kB - much higher than Tom Greenwood’s recommendation of 500kB. This was mostly due to the large number of high-resolution images on these pages. By using the tool to identify where the majority of our emissions came from, we were also able to identify possible reasons why the emissions were so high and are now using this knowledge to inform practise and policy on how we develop, build and maintain our websites.

Digital Sustainability Day and what’s next?

On Monday 27 September, our digital sustainability working group organised our first ever internal Digital Sustainability Day. The purpose of the day was to educate colleagues and raise awareness of this topic as well as inspire them to start taking action in their own areas. One of the talks during the day was led by Tom Greenwood who shared his knowledge and experience in creating sustainable websites. Tom spoke about website page weight and how using DIMPACT data can help user experience and technology teams to improve our end user device emissions based on page weight.

We are only at the beginning of our journey to understand the full impact of our digital carbon footprint and next steps include an examination of our emissions data from pre and post pandemic, with a comparison on 2021 data. We also intend to create a methodology and calculations for roll out across Cambridge University Press & Assessment so that we can embed digital sustainability thinking across all areas of the organisation.

A year ago, we were still wondering what our digital carbon footprint would be and now we’ve identified areas where real action can be taken to create more sustainable digital products for our researchers, learners, teachers and parents.

Visit our sustainability pages to read about our commitment to working sustainably and ethically, and steps we are taking to reduce our environmental impact.