Calculating greenhouse gas emissions

Greenhouse gas emissions calculations is one tool to assess the climate impact of a product or service. However, an aggregated value of the greenhouse gas emissions does not necessarily give the whole picture.

The result of such a calculation can vary a lot depending on data quality, system boundaries, choices and assumptions made and the time perspective. This means it may be difficult to interpret the result and compare it with other calculations.

In greenhouse gas emissions calculations, emissions from different gases are included, for example carbon dioxide, methane, nitrous oxide etc. Calculations can cover the whole life cycle, or it can be done for a part of the life cycle where the climate impact is considered particularly significant. Focus can be only on direct emissions, or indirect emissions can also be included. Direct emissions are emissions from sources owned or controlled by the company itself, while indirect emissions are emissions occurring elsewhere in the supply chain or as a result of purchased energy.

There are different standards for greenhouse gas emissions calculations, for example the GHG Protocol or ISO14067 (Greenhouse gases – Carbon footprint of products). However, there is a significant flexibility within these standards.

How does the Nordic Swan Ecolabel contribute?

Nordic Ecolabelling may require greenhouse gas calculations in order to help companies identify hotspots or show fulfilment of a requirement for limited climate impact. Greenhouse gas emissions calculations are required or promoted in some of the criteria for the Nordic Swan Ecolabel where calculations are assessed as a useful tool.

Nordic Ecolabelling takes the following aspects into account when considering if and how greenhouse gas emissions calculation would be included in the criteria:

  • Does the product/service have a high climate impact?
  • Is a greenhouse gas emission calculation an effective way to identify hotspots or handle the impact on climate change?
  • Should the calculation be set to the whole life cycle or be limited to the specific life cycle stages that are considered to have significant climate impact?
  • Are data of good quality available, especially for the most relevant processes?
  • Is a clear calculation methodology for the product area laid down in an official regulation?

To obtain useful results, clear rules must be set up. Transparency of the calculation is also crucial.

If Nordic Ecolabelling accepts greenhouse gas emission calculations for the whole life cycle, made by companies themselves, the calculation must as a minimum be made according to the GHG Protocol methodology, but other specific standards can be required for specific product groups. Details of how the result are calculated with reference to e.g., system boundaries, assumptions and factors used must always be clear.