In October 2024 Circular Communities Scotland received funding from Zero Waste Scotland to develop a prototype carbon calculator tool for the circular economy sector in Scotland.
The funding was awarded following the publication of our Feasibility Study in 2023, which reviewed existing carbon models and found that there is currently no single tool that covers reuse, repair and sharing.
The project was funded until March 2025, and achieved its goal of developing a prototype carbon calculator that can measure the reduced climate change impact (in kgCO2e) of the sharing, repair and reuse sectors due to the displacement of primary goods and materials.
To create this tool Circular Communities Scotland worked collaboratively with a freelance Carbon Model Coordinator, Steve Privett, who developed the prototype with support from Professor Angela Druckman, Emerita Professor of Sustainable Consumption and Production at the University of Surrey. Additionally, the project was supported by an advisory group, made up of representatives from Scottish Government, Zero Waste Scotland, and members of Circular Communities Scotland.
The calculator works with a database of embodied greenhouse gas (GHG) emissions, and estimated displacement rates for the most popular produce item types, along with estimates of operational emissions for reuse organisations, to calculate the estimated net carbon emission from the use of reuse, repair and sharing services. To populate this database, we are very grateful for the support of six Circular Communities Scotland member organisations who took the time to share their operational and utility data with us, which form the backbone to this prototype:
- Transition Stirling
- Edinburgh Tool Library
- Cunninghame Furniture
- The Reuse Shop (Stranraer)
- Remake Scotland (Crieff)
- The Edinburgh Remakery
About the Prototype
The Feasibility Study highlighted that reuse, repair and sharing organisations need a simple, easy to use, Scotland-focused tool to calculate their environmental impact so that they can communicate their environmental impact with greater confidence. By having a standard shared dataset across the sector, Circular Communities Scotland will be able to better represent the environmental impact of the sector, encourage more funding and resources towards the sector, and better influence developing policy areas due to our more informed position. Finally, funders, partnership organisations and policy stakeholders will benefit from the calculator as the resulting data will be useful in making informed policy decisions for Scotland’s circular economy.
With this in mind, it was important that the prototype was designed in a way that was easy to use, but which reported useful data – useful to the organisations themselves, but also to the wider sector. Two versions of the calculator were developed: a Simple Version, and a Detailed Version.
The Simple Version simply requires organisations to enter the total number of items reused, shared and/or repaired (i.e. not separated by categories), and based on the relative size of the operation, estimates are used to produce a carbon emission saving and product waste saving:
Figure 1 The Simple Version of the prototype Carbon Calculator asks users to enter the total number of items reused, regardless of product category (there is a separate page for sharing and repairing).
Figure 2 The Simple Version of the Prototype uses estimated values alongside the values entered by the user to calculate carbon emissions saved and product waste saving.
The Detailed Version of the Carbon Calculator requires users to enter in the total number of items reused, shared and/or repaired by product category.
Figure 3 The Detailed Version of the Prototype requires users to enter in the number of items reused by category.
In addition to entering the number of items reused, shared and repaired by category, organisations using the prototype also have the option to enter in data for their utilities, waste and transport. If they do not have this information they can opt to use estimated values based on organisations of similar size/type.
Figure 4 The Detailed Version of the prototype allows organisations to enter their transport data, which for clarity is separated into staff and organisation transport use.
The results include a summary page that is the same as for the Simple Version, which visually shows the carbon emissions saved and product waste savings. Both versions also include a detailed results page, which breaks down carbon emissions by product type, and provides a record of the information entered by the user. This summary can be downloaded and saved as a PDF file.
Below is a guided demonstration of the prototype from our CEO, Michael Cook:
Michael highlights the need for this carbon calculator in the sector:
“Historically our membership uses different criteria and measurements to assess and communicate their environmental and social impact. Whilst Circular Communities Scotland has sought to talk about the overall impact of the sector, this has necessarily been at the highest level and with a degree of estimation. We wish to support our members, and the wider sector, by enabling them to confidently measure and communicate their environmental and social impact on a consistent basis”.
Vision for the Future
In addition to measuring the environmental impact of the circular economy sector, the incredible social impact that our members have in their communities and beyond cannot be understated. With further funding this prototype calculator will be developed into an online tool, accessible to all within the sector, and include a metric for measuring social impact.
A Senior Policy Officer from SEPA said in response to the Carbon Project:
“Only by developing and testing new approaches to gathering data on reuse will it ever be possible to move towards reuse targets – targets with no calculation or reporting methodology behind them are of no value. This project will enable a greater understanding of what information can be produced. It would be separate from but complimentary to SEPA’s waste data publications and could help pave the way towards targets – maybe in combination with survey data from online marketplaces and other sources of information”.
We would like to thank Zero Waste Scotland for funding both the initial Feasibility Study and the development of the prototype calculator. Unfortunately, our preferred source of funding to take this tool online has been unsuccessful. Circular Communities Scotland is currently considering our options for taking this project forward through alternative funding.