There are several different ways of measuring a financial asset portfolio’s carbon footprint. TCFD mentions five, including portfolio-weighted carbon intensity that is recommended for this purpose. However, there are also alternatives when it comes to this measure for portfolios of bonds issued by states and regions. One alternative to using GDP as a measure of the country´s or region’s output is to use GDP per capita. GDP measures the total economic activity in the country, while GDP per capita gives an indication of the country’s welfare, as it gives an indication of how much is produced per person in a country, and thus how productive the country’s inhabitants are on average. By dividing greenhouse gas emissions for each country by GDP per capita, a different ratio is achieved between the carbon intensity of the countries and regions and thus the carbon footprint of the entire portfolio. This may in turn lead to two different asset portfolios being related to one another in entirely different ways, depending on the definition of the carbon footprint used. No result is wrong, only different, and the right measure to use is determined by the purpose of the analysis. In this Commentary, the Riksbank uses the production-based measure that uses GDP. This is because the objective is to compare countries based on their total estimated greenhouse gas emissions from the production of goods and services within the country or region.