I’ve looked at the sources of this paper, and it looks like the grams of CO2 per email are taken out of the ass, as it’s just a random value in „SAMRIDDHI Volume 15, Issue 1, 2023 Print ISSN: 2229-7111 Online ISSN: 2454-5767 Survey on Carbon Dioxide Emissions Through Email Conversion”

Microsoft is big tech, and GitHub is owned by y Microsoft.

My take is that it’s already your systems feature, rather than admins responsibility. If you treat departments like customers, you’d find a good way to spread the costs. If something is just a „common infrastructure”, you will always find something that makes costs that doesn’t have an easy way to track who triggered that - because you don’t pass enough information with it.

Not sure what is hard in it - you need consistent tagging, and that by itself gives you a lot of mileage in cost explorer.