This page explains how the ekko Climate API estimates the carbon footprint of a transaction.

What is the carbon footprint?

The carbon footprint is ekko's estimate of the greenhouse gas (GHG) emissions linked to a transaction, expressed in CO₂e (carbon dioxide equivalent). The API also returns relatable equivalents, such as kilometres driven or hours of phone charging, so consumers can understand the scale of the footprint.

How the calculation works

Each transaction is categorised using a Merchant Category Code (MCC). The MCC identifies the type of goods or services purchased, for example groceries or travel.

The MCC is then mapped to global emissions datasets such as EXIOBASE, which contain detailed information on the emissions profile of different industries and their supply chains. By combining the MCC with the purchase value and country, the API estimates the emissions for that transaction.

The methodology accounts for both direct emissions and the wider supply chain, since most greenhouse gas emissions occur during production and transport rather than at the point of sale.

Accuracy and limitations

Payment data doesn't currently provide item-level detail. For example, there's no way to distinguish whether a grocery transaction included beef or vegetables. The carbon footprint is therefore an estimate at the sector level, not a precise measure of a specific product.

The carbon footprint is an indicator designed to give consumers a meaningful sense of the environmental footprint of their spending. As data sources and methodology improve, ekko updates the model to reflect the latest science.

Methodology partnership

The carbon footprint methodology was developed in partnership with Nature Positive, an organisation that specialises in environmental data and measurement. The methodology is based on internationally recognised greenhouse gas accounting standards and trusted datasets including EXIOBASE.