For internal use, AI generally weighs less than 1% of the footprint: from a few kilograms of CO2e per year for a small organisation to a few tonnes for 200 employees with intensive generative use. That is marginal but real, and it should be documented. If your company builds AI into a product or service it sells, however, use by your customers can make it a much heavier emission source.
Read the source article: AI Scope 3 emissions: how to count AI in your carbon footprint