According to the framework of the Task Force on Climate-Related Financial Disclosures (TCFD): the formula...

The Task Force on Climate-Related Financial Disclosures (TCFD) framework uses the weighted average carbon intensity metric, which calculates carbon intensity based on an issuer's revenue. The formula is as follows: \text{Weighted Average Carbon Intensity} = \sum \left( \frac{\text{Current Value of Investment}}{\text{Current Portfolio Value}} \times \frac{\text{Issuer’s Scope 1 and 2 Emissions}}{\text{Issuer’s Revenue in US$m}} \right) This approach helps investors understand their portfolio's exposure to carbon-intensive companies based on financial performance metrics such as revenue​​.