Spend-based carbon accounting

Spend-based carbon accounting uses the economic value of a good or service together with a corresponding emission factor (e.g. kg CO₂e per €) to calculate the emissions caused.

The activity-based emissions calculation is a precise method for quantifying greenhouse gas emissions (GHG), in which emissions are determined by multiplying physical units of an activity by the corresponding emission factors. Examples of such activities include fuel consumption, material usage in production processes, or the kilometers traveled for transport. The emission factor indicates how much CO₂ equivalent is released per unit of activity, which forms the basis for the calculation.This method is considered the gold standard of carbon accounting, as it is based on real data, thus providing higher accuracy and transparency than other approaches, such as expenditure-based calculations. The advantage of the activity-based method lies in its high accuracy and the ability to precisely attribute emissions to individual sources. At the same time, the results are independent of price fluctuations, which excludes the influence of financial factors and makes the content clearer and more understandable for companies.The activity-based method is particularly applied in companies with complex supply chains, as it allows for the development of targeted reduction measures and compliance with regulatory requirements. However, collecting the necessary activity data can present technical challenges that require investments in measurement systems and careful data sharing. Overall, activity-based emissions calculation offers an indispensable tool for effective sustainability management and meeting societal expectations for transparent climate protection measures.