Suppliers publish little at service level: only Google has published an official measurement (0.24 Wh per median Gemini query). You combine an energy-per-query figure from independent benchmarks, tied to a specific model, with the electricity mix of the data centres' region, and use ADEME's Base Empreinte® for the factors surrounding AI (equipment, cloud). A proxy factor that is dated, sourced and given with its uncertainty stands up to scrutiny.
Read the source article: AI Scope 3 emissions: how to count AI in your carbon footprint