Spend-based method
The spend-based method estimates emissions by applying secondary emission factors to the economic value of goods and services.
You can apply the spend-based method to Category 1 and 2 in the same way. The spend-based method involves multiplying the total spend on purchased goods and services by an emission factor. The emission factor is a value that represents the average emissions that are associated with a unit of spend. You can obtain the factor from various sources, such as industry averages or life cycle assessment (LCA) studies. The resulting emissions estimate is then reported as the scope 3 category 1 emissions.
For example, suppose that a company spends $100,000 on purchased goods and services in a year, and the emission factor for category 1 is 0.5 tons CO2e per dollar spent. Using the spend-based method, the company's scope 3 category 1 emissions are estimated as 100,000 x 0.5, which is 50,000 tons CO2e.
